Coles was founded by George James (G.J.) Coles when what was called the "Coles Variety Store" opened on 9 April 1914 in Smith Street in the [[Melbourne]] suburb of [[Collingwood, Victoria|Collingwood]]. Expansion to more stores occurred and the chain was regarded as leaders in providing value to Australian shoppers (G. J. Coles learned the retail trade working for his father's "Coles Store" business at Wilmot, Tasmania between 1910 and 1913).
Coles' interest in food retailing was spurred in 1958 when it acquired 54 John Connell Dickins grocery stores. It then acquired the Beilby's chain in South Australia in 1959 and 265 Matthews Thompson grocery stores in New South Wales in 1960.{{cite web|publisher=Encyclopedia of Business|title=Coles Myer Limited|url=http://www.referenceforbusiness.com/history2/9/Coles-Myer-Ltd.html|accessdate=2009-06-24}}
[[File:Coles Dee Why.jpg|thumb|An entrance to a Coles supermarket in [[Dee Why, New South Wales]].]]
[[File:Refurbished Coles supermarket in Berwick.jpg|thumb|Inside a Coles supermarket in [[Berwick, Victoria]].]]
[[File:Coles South City aisle.jpg|thumb|An aisle in a Coles supermarket in [[Glenfield Park, New South Wales|Glenfield Park]]]]
In 1960 the first supermarket was opened in the Melbourne suburb [[Balwyn North, Victoria|Balwyn North]], at the corner of Burke and Doncaster Roads where a modernised version continues to operate. By 1973 Coles had established stores in all Australian capital cities.
From 1962 its supermarkets were branded ''Coles New World'' with accompanying rocket imagery.{{cite web|title=Coles|url=http://www.emelbourne.net.au/biogs/EM00373b.htm|publisher=eMelbourne - The Encyclopaedia of Melbourne Online|accessdate=7 July 2010}} In 1991 the stores were rebranded ''Coles Supermarkets'' and from 1998 simply as ''Coles''.
From mid 2006, many [[BI-LO (Australia)|BI-LO]] supermarkets were badged as Coles Supermarkets. Newmart supermarkets, under which BI-LO traded in Western Australia, were badged as Coles Supermarkets in 2002-2003. Newmart stores co-located with Coles in the same area or shopping centre were sold to Foodland and re branded as the now-defunct [[Action Supermarkets]] chain. The conversion program was put on hold at Easter 2007.{{cite news|url=http://www.smh.com.au/news/business/coles-supermarket-sales-drop/2007/05/17/1178995276828.html|title=Coles Supermarket Sales Drop|date=2007-05-17|accessdate=2007-08-23|publisher=Sydney Morning Herald}}
On 2 July 2007, Western Australian based company [[Wesfarmers]] agreed to purchase Coles Group Limited for A$22 billion. The purchase was completed in early 2008.{{cite news|title=Coles sold for $22 billion|date=2007-07-02|accessdate=2007-08-01|publisher=Herald Sun, Melbourne|url=http://www.news.com.au/business/story/0,23636,22003301-14334,00.html |archiveurl = http://web.archive.org/web/20070706033113/http://news.com.au/business/story/0,23636,22003301-14334,00.html |archivedate = 2007-07-06}}
In August 2007, as Wesfarmers foreshadowed its plans for the restructuring of Coles Group following its anticipated takeover, it stated that one of three planned divisions would comprise supermarkets, liquor and convenience stores.{{cite news|title=Wesfarmers plans Coles investment, restructuring|publisher=Reuters|date=2007-08-16|accessdate=2007-08-16|url=http://www.reuters.com/article/innovationNews/idUSSYD11087920070816?sp=true}}
In February 2008, Wesfarmers appointed UK retailer Ian McLeod as managing director of Coles Supermarkets plus liquor, fuel and convenience businesses. McLeod's previously headed UK car parts and cycle retailer [[Halfords]] and gained supermarket experience with [[Asda]] and [[Wal-Mart]].{{cite web|publisher=Sydney Morning Herald|date=2008-02-07|accessdate=2008-02-09|title=UK retailer to head up Coles|url=http://news.smh.com.au/uk-retailer-to-head-up-coles/20080207-1qti.html}}
In 2008, the ''I Test For Coles Panel'' (or ''Coles Mums' Panel'') began, with 2,500 panelists testing Coles brand products in their home and providing general feedback about Coles.{{cite web|title=Coles Mums Panel|url=http://www.coles.com.au/Products/Our-Brands/Coles-Mums-Panel.aspx|publisher=Coles|accessdate=7 July 2010}}
In February 2011, Coles acquired [[National Australia Bank]]'s 50 per cent interest in Australia's largest loyalty program [[FlyBuys (Australia)|FlyBuys]], giving it 100% ownership.{{cite news|publisher=Inside Retailing|url=http://www.insideretailing.com.au/Latest/tabid/53/ID/10102/Coles-buys-out-FlyBuys.aspx|title=Coles buys out FlyBuys|accessdate=16 February 2011|date=16 February 2011}}
Tuesday, 12 April 2011
Coles
Type: Subsidiary
Industry: Retail
Founded: 1914
Headquarters: Glen Iris, Victoria, Australia
Number of locations: 742 (including 48 BI-LO supermarket)
Key people: Ian McLeodManaging Director
Employees: 93,000+
Parent: Wesfarmers
Website: www.coles.com.au
Industry: Retail
Founded: 1914
Headquarters: Glen Iris, Victoria, Australia
Number of locations: 742 (including 48 BI-LO supermarket)
Key people: Ian McLeodManaging Director
Employees: 93,000+
Parent: Wesfarmers
Website: www.coles.com.au
Monday, 4 April 2011
Aviation disaster 27 march 1977 : A Case Study
BY KUSHAL SHRESTHA
Los Rodeos, Tenerife's North airport is, unfortunately, famous for the fateful accident which occurred on March 27, 1977, in which 583 people died when KLM and Pan Am 747s collided on a crowded, foggy runway in Tenerife, Canary Islands. The incident remains the world's worst aviation accident in history.
On 27 March 1977, a KLM-Royal Dutch Airlines Boeing 747 collided with a Pan American Boeing 747 in poor visibility at the Los Rodeos Airport, Tenerife, Canary Islands
*Probable Cause
The Subsecretaria de Aviacion Civil Report gave the probable cause of this accident:
The KLM aircraft had taken off without take-off clearance, in the absolute conviction that this clearance had been obtained, which was the result of a misunderstanding between the tower and the KLM aircraft. This misunderstanding had arisen from the mutual use of usual terminology which, however, gave rise to misinterpretation. In combination with a number of other coinciding circumstances, the premature take-off of the KLM aircraft resulted in a collision with the Pan Am aircraft, because the latter was still on the runway since it had missed the correct intersection
*Contributing Factors
“Considered factors” which contributed to the accident were (1) inadequate language, i.e., nonstandard phraseology from the KLM first officer and tower controller, (2) the Pan Am flight crew missing the correct taxiway, and (3) unusual traffic congestion, which required back-taxi operations on the active runway.
*Background
Both flights were rerouted from their original destination of Las Palmas, Canary Island, as a result of a terrorist bombing at the Las Palmas terminal. Local police had no alternative but to close the airport while they conducted a thorough search.
*Weather
On the day of the accident, light rain and patch low clouds covered the Los Rodeos Airport most of the early afternoon, which the KLM and Pan Am flights arrived. Fog and light rain persisted over the runway for the 30 minutes prior to the accident.
*History of Flights
KLM Flight 4805 was a chartered flight that originated from Amsterdam’s Schiphol Airport on the morning of the accident. The flight carried 234 holiday passengers, most of whom were Dutch, bound for the Las Palmas Airport, Grand Canary Island. The flight from Amsterdam to Las Palmas was four hours.
Pan Am Flight 1736 was a chartered flight that originated in Los Angeles, on the afternoon of 26 March. There were 364 passengers, mostly retires, boarded for the first leg of their trip to Las Palmas. From Grand Canary, they were to embark on a 12-day Mediterranean cruise.
KLM Flight 4805 was one of the first diverted flights that landed at Los Rodeos. The parking area and main taxiway were already full with airplanes that had been previously diverted by the time Flight 4805 cleared the runway.
The captain of Pan Am asked the Las Palmas controller if, instead of diverting to Los Rodeos, they could continue holding over Las Palmas. The controller refused the captain’s request and diverted the flight to Los Rodeos. Pan Am landed at 1345 and was instructed to park directly behind KLM Flight 4805.
*Pilot Experience
The KLM Captain had a total of 11,700 flight hours, 1545 in the Boeing 747. He was KLM’s chief training captain for the 747 and was featured in company advertisements, including those in in-flight magazines. The captain had spent recent years in the 747 training facility and did not typically fly much on scheduled flights.
*Language Barrier
The Spanish controllers at Los Rodeos had difficulty communicating in English. This was evident from the numerous misunderstandings and communication breakdowns between them and the KLM and Pan Am flight crews. Furthermore, the Dutch first officer, who was communicating on behalf of the KLM flight, used nonstandard ATC phraseology, some of which were most likely linked to his speaking English as a second language.
*Analyses – Flight Crew Judgment and Decision Making
Because of instances in previous years in which pilot fatigue seriously jeopardized the safety of a number of flights, the Dutch civil aviation authority required flight crews to observe rigid duty times, without exception.
From cockpit conversations, the KLM captain was worried about these restrictions and wanted to avoid the burden of remaining overnight with hundreds of passengers. He contacted the operations office in Amsterdam and was told that he had until 1830 to arrive back to Amsterdam. Shortly thereafter, ATC notified the waiting aircraft that Las Palmas Airport had just reopened.
The Captain’s worries were still not over. He needed to refuel prior to the flight into Amsterdam and with the dozens of aircraft soon arriving at Las Palmas, many presumably requiring refueling, the captain decided to refuel before departing Los Rodeos.
The Pan Am flight crew prepared to taxi but was told by the tower controller that while there was no delay in obtaining a departure clearance, the only way to the active runway was to maneuver around the KLM, which by that time had begun refueling. Undoubtedly frustrated, the Pan Am first officer radioed the KLM flight crew and asked how long the refueling would take. They were abruptly told, “About 35 minutes.” The first officer and second officer climbed down to the ground to determine if there was enough room to clear the KLM jet, but soon realized that the KLM had them blocked in and they would have to wait for the KLM to finish refueling.
Meanwhile, the weather at Los Rodeos began to deteriorate with poor surface visibility and light rain, adding to the stress already mounting for both flight crews. Moreover, the flight crews were most assuredly feeling tired – the Pan Am flight crew had been on duty for over 9 hours and the KLM flight crew for over 11 hours.
By 1625, the KLM jet was refueled and the flight crew was directed to back-taxi on runway 12 in preparation for departure on runway 30. As the KLM proceeded to move out of the congested area, the Pan Am crew received clearance to taxi a similar route as the KLM. When the Pan Am reached the holding point for runway 12, the foggy conditions had worsened over the runway.
The Pan Am crew, taxiing in the fog and a some distance from the KLM, was having difficulty understanding their taxi instructions. Reviewing the airport diagram, much like a road map, they continued their back-taxi on runway 12. The last taxiway (C4) was a high-speed taxiway for runway 12 – an easy 45-degree turn from their direction. The Pan Am first officer asked ground, “Would you confirm that you want us to turn left at the third intersection?” The controller replied, “The third one, Sir…one, two, three…third one.” The Pan Am flight crew began their pre-takeoff checklists as they continued searching for the third taxiway. The ground controller told them to report leaving the runway, and the first officer acknowledged the instructions.
Meanwhile, the KLM crew had reached the end of the runway and had made their 180-degree turn for the departure heading on runway 30. The Pan Am flight crew heard the KLM pilot ask the controller to turn on the runway centerline lights. The controller replied to both the KLM and the Pan Am flight crews that the lights were out of service.
Shortly thereafter, at 1705, the KLM captain allowed the aircraft to roll forward. The first officer stopped him and said, “Wait a minute, we don’t have an ATC clearance.” The captain stepped on the brakes and replied, “No…I know that. Go ahead and ask.” The first officer then contacted the tower controller, “KLM 4805 is now ready for takeoff…we’re waiting for our ATC clearance.” The tower controller replied with their departure clearance.
As the first officer began to read back the clearance to the tower controller, the captain released the brakes and started the takeoff roll saying, “Let’s go.” By the time the first officer completed the read-back, the aircraft was six seconds into the takeoff roll, so he added, “We are now at takeoff.” The tower controller interpreted the comment that the KLM was ready for takeoff. He told the flight crew, “OK…standby for takeoff…I will call you.”
Upon hearing that the KLM jet was “at takeoff,” the Pan Am first officer called the controller and said, “We are still taxiing down the runway.” The tower controller replied, “Roger, Clipper [universal Pan Am call sign] 1736, report clear of the runway.” The first officer responded “Roger will report when clear.” The tower controller acknowledged, “Roger papa alpha 1736, report the runway clear.” Inexplicably, the control used “papa alpha,” a call sign that would not typically register to other flight crews as a Pan Am Clipper jet. Compounding this ambiguous remark, and unbeknownst to the Pan Am flight crew and the tower controller, when the first officer made his urgent call to tell the controller that they were still taxiing on the runway, he “stepped on” the final portion of the controller’s transmission to the KLM flight crew. All they heard was “…k,” followed by a three-second, high pitched squeal. Instead of, “OK…standby for takeoff…I will call you.”
About 20 seconds into their takeoff roll, the KLM second officer asked the captain and first officer, “Did he not clear the runway then?” The captain asked, “What did you say?” The second officer repeated, “Did he not clear the runway, that Pan American?” Both pilots answered unequivocally that the Pan Am had cleared the runway.
The Pan Am jet was still taxiing on the runway after the flight crew missed the intersection for the third taxiway. The captain, apparently uneasy about remaining on an active runway in poor visibility told his crew, “Let’s get the hell right out of here!”
A few seconds later, the Pan Am flight crew saw the diffused landing light of the KLM jet begin to shake through the fog bank, indicating that the aircraft was moving down the runway. The Pan Am captain exclaimed, “There he is…look at him…[expletives]…coming!” Pushing the throttles full forward and turning a hard left, the captain made a desperate attempt to get off the runway. The first officer frantically yelled, “Get off! Get off! Get off!”
The Pan Am jet was at a 45-degree angle relative to the runway centerline. The KLM first officer called “V1” most likely at the precise moment that his captain saw the Pan Am jet directly in front of him. The KLM captain instantaneously rotated, scraping the tail for a distance of 65 feet. Fully airborne, its nose gear narrowly passed over the Pan Am, but there was not enough clearance and the main landing gear slammed broadside against the Pan Am. The impact sheared off the fuselage, destroying the upper deck just behind the flight deck. Both aircraft caught fire. The KLM jet remained airborne for a few seconds before hitting the ground 150 meters past the crash site and then sliding another 300 meters on the runway. The aircraft violently burst into a raging inferno.
*Accident Survivability
A Total of 583 passengers and crew perished between both aircraft making it the most deadly accident in aviation history. There were 234 passengers and 14 crew on board KLM Flight 4805; none survived.
On Pan Am Flight 1736, there were 335 fatalities, including nine members of the cabin crew. There were 77 survivors, including the flight crew. The impact destroyed the first-class lounge on the upper deck, causing the lounge floor to collapse onto the first-class section in the main cabin. None of those in the first-class lounge survived. According to some survivors, the shock of impact was not excessively violent, leading them to believe that the cause of was an explosion.
Many of the Pan Am passengers who were seated on the right side of the aircraft were killed instantly from the initial impact. Dozens more, who were seated in the center and aft of the fuselage, survived the impact but became trapped by the twisted metal and debris and thus were unable to escape the spreading fire. There were reports of other passengers who survived the impact but who became incapacitated from shock and fell into catatonic states, unable to move from their seats and flee the burning aircraft.
*Analyses and Lessons Learned
Communication errors, a rushed departure, monitoring and challenging errors, and poor visibility proved a deadly combination of factors that culminated with a disaster of historic proportions. While individually these factors posed a threat to safety, the most critical error committed that day was when the KLM captain departed without takeoff clearance, in the fog, when he knew that under the unusual circumstances other aircraft would be back-taxing to the departure end of the runway.
The safety analyst believed it was possible that the KLM first officer who had only 95 hours in the 747, and who was flying with the KLM Chief 747 Instructor, may have become intimidated by the captain’s legendary status. Being new to the jet and crewed with someone so well-respected may have caused him to second guess the circumstances.
*Reference
“Subsecretaria de Aviacion Civil” Accident Report, 1978. ICAO Circular 153-AN/56. Shari Stamford Krause.
Tenerife Airport Disaster - Wikipedia
Los Rodeos, Tenerife's North airport is, unfortunately, famous for the fateful accident which occurred on March 27, 1977, in which 583 people died when KLM and Pan Am 747s collided on a crowded, foggy runway in Tenerife, Canary Islands. The incident remains the world's worst aviation accident in history.
*Probable Cause
The Subsecretaria de Aviacion Civil Report gave the probable cause of this accident:
The KLM aircraft had taken off without take-off clearance, in the absolute conviction that this clearance had been obtained, which was the result of a misunderstanding between the tower and the KLM aircraft. This misunderstanding had arisen from the mutual use of usual terminology which, however, gave rise to misinterpretation. In combination with a number of other coinciding circumstances, the premature take-off of the KLM aircraft resulted in a collision with the Pan Am aircraft, because the latter was still on the runway since it had missed the correct intersection
*Contributing Factors
“Considered factors” which contributed to the accident were (1) inadequate language, i.e., nonstandard phraseology from the KLM first officer and tower controller, (2) the Pan Am flight crew missing the correct taxiway, and (3) unusual traffic congestion, which required back-taxi operations on the active runway.
*Background
Both flights were rerouted from their original destination of Las Palmas, Canary Island, as a result of a terrorist bombing at the Las Palmas terminal. Local police had no alternative but to close the airport while they conducted a thorough search.
*Weather
On the day of the accident, light rain and patch low clouds covered the Los Rodeos Airport most of the early afternoon, which the KLM and Pan Am flights arrived. Fog and light rain persisted over the runway for the 30 minutes prior to the accident.
*History of Flights
KLM Flight 4805 was a chartered flight that originated from Amsterdam’s Schiphol Airport on the morning of the accident. The flight carried 234 holiday passengers, most of whom were Dutch, bound for the Las Palmas Airport, Grand Canary Island. The flight from Amsterdam to Las Palmas was four hours.
Pan Am Flight 1736 was a chartered flight that originated in Los Angeles, on the afternoon of 26 March. There were 364 passengers, mostly retires, boarded for the first leg of their trip to Las Palmas. From Grand Canary, they were to embark on a 12-day Mediterranean cruise.
KLM Flight 4805 was one of the first diverted flights that landed at Los Rodeos. The parking area and main taxiway were already full with airplanes that had been previously diverted by the time Flight 4805 cleared the runway.
The captain of Pan Am asked the Las Palmas controller if, instead of diverting to Los Rodeos, they could continue holding over Las Palmas. The controller refused the captain’s request and diverted the flight to Los Rodeos. Pan Am landed at 1345 and was instructed to park directly behind KLM Flight 4805.
*Pilot Experience
The KLM Captain had a total of 11,700 flight hours, 1545 in the Boeing 747. He was KLM’s chief training captain for the 747 and was featured in company advertisements, including those in in-flight magazines. The captain had spent recent years in the 747 training facility and did not typically fly much on scheduled flights.
*Language Barrier
The Spanish controllers at Los Rodeos had difficulty communicating in English. This was evident from the numerous misunderstandings and communication breakdowns between them and the KLM and Pan Am flight crews. Furthermore, the Dutch first officer, who was communicating on behalf of the KLM flight, used nonstandard ATC phraseology, some of which were most likely linked to his speaking English as a second language.
*Analyses – Flight Crew Judgment and Decision Making
Because of instances in previous years in which pilot fatigue seriously jeopardized the safety of a number of flights, the Dutch civil aviation authority required flight crews to observe rigid duty times, without exception.
From cockpit conversations, the KLM captain was worried about these restrictions and wanted to avoid the burden of remaining overnight with hundreds of passengers. He contacted the operations office in Amsterdam and was told that he had until 1830 to arrive back to Amsterdam. Shortly thereafter, ATC notified the waiting aircraft that Las Palmas Airport had just reopened.
The Captain’s worries were still not over. He needed to refuel prior to the flight into Amsterdam and with the dozens of aircraft soon arriving at Las Palmas, many presumably requiring refueling, the captain decided to refuel before departing Los Rodeos.
The Pan Am flight crew prepared to taxi but was told by the tower controller that while there was no delay in obtaining a departure clearance, the only way to the active runway was to maneuver around the KLM, which by that time had begun refueling. Undoubtedly frustrated, the Pan Am first officer radioed the KLM flight crew and asked how long the refueling would take. They were abruptly told, “About 35 minutes.” The first officer and second officer climbed down to the ground to determine if there was enough room to clear the KLM jet, but soon realized that the KLM had them blocked in and they would have to wait for the KLM to finish refueling.
Meanwhile, the weather at Los Rodeos began to deteriorate with poor surface visibility and light rain, adding to the stress already mounting for both flight crews. Moreover, the flight crews were most assuredly feeling tired – the Pan Am flight crew had been on duty for over 9 hours and the KLM flight crew for over 11 hours.
By 1625, the KLM jet was refueled and the flight crew was directed to back-taxi on runway 12 in preparation for departure on runway 30. As the KLM proceeded to move out of the congested area, the Pan Am crew received clearance to taxi a similar route as the KLM. When the Pan Am reached the holding point for runway 12, the foggy conditions had worsened over the runway.
The Pan Am crew, taxiing in the fog and a some distance from the KLM, was having difficulty understanding their taxi instructions. Reviewing the airport diagram, much like a road map, they continued their back-taxi on runway 12. The last taxiway (C4) was a high-speed taxiway for runway 12 – an easy 45-degree turn from their direction. The Pan Am first officer asked ground, “Would you confirm that you want us to turn left at the third intersection?” The controller replied, “The third one, Sir…one, two, three…third one.” The Pan Am flight crew began their pre-takeoff checklists as they continued searching for the third taxiway. The ground controller told them to report leaving the runway, and the first officer acknowledged the instructions.
Meanwhile, the KLM crew had reached the end of the runway and had made their 180-degree turn for the departure heading on runway 30. The Pan Am flight crew heard the KLM pilot ask the controller to turn on the runway centerline lights. The controller replied to both the KLM and the Pan Am flight crews that the lights were out of service.
Shortly thereafter, at 1705, the KLM captain allowed the aircraft to roll forward. The first officer stopped him and said, “Wait a minute, we don’t have an ATC clearance.” The captain stepped on the brakes and replied, “No…I know that. Go ahead and ask.” The first officer then contacted the tower controller, “KLM 4805 is now ready for takeoff…we’re waiting for our ATC clearance.” The tower controller replied with their departure clearance.
As the first officer began to read back the clearance to the tower controller, the captain released the brakes and started the takeoff roll saying, “Let’s go.” By the time the first officer completed the read-back, the aircraft was six seconds into the takeoff roll, so he added, “We are now at takeoff.” The tower controller interpreted the comment that the KLM was ready for takeoff. He told the flight crew, “OK…standby for takeoff…I will call you.”
Upon hearing that the KLM jet was “at takeoff,” the Pan Am first officer called the controller and said, “We are still taxiing down the runway.” The tower controller replied, “Roger, Clipper [universal Pan Am call sign] 1736, report clear of the runway.” The first officer responded “Roger will report when clear.” The tower controller acknowledged, “Roger papa alpha 1736, report the runway clear.” Inexplicably, the control used “papa alpha,” a call sign that would not typically register to other flight crews as a Pan Am Clipper jet. Compounding this ambiguous remark, and unbeknownst to the Pan Am flight crew and the tower controller, when the first officer made his urgent call to tell the controller that they were still taxiing on the runway, he “stepped on” the final portion of the controller’s transmission to the KLM flight crew. All they heard was “…k,” followed by a three-second, high pitched squeal. Instead of, “OK…standby for takeoff…I will call you.”
About 20 seconds into their takeoff roll, the KLM second officer asked the captain and first officer, “Did he not clear the runway then?” The captain asked, “What did you say?” The second officer repeated, “Did he not clear the runway, that Pan American?” Both pilots answered unequivocally that the Pan Am had cleared the runway.
The Pan Am jet was still taxiing on the runway after the flight crew missed the intersection for the third taxiway. The captain, apparently uneasy about remaining on an active runway in poor visibility told his crew, “Let’s get the hell right out of here!”
A few seconds later, the Pan Am flight crew saw the diffused landing light of the KLM jet begin to shake through the fog bank, indicating that the aircraft was moving down the runway. The Pan Am captain exclaimed, “There he is…look at him…[expletives]…coming!” Pushing the throttles full forward and turning a hard left, the captain made a desperate attempt to get off the runway. The first officer frantically yelled, “Get off! Get off! Get off!”
The Pan Am jet was at a 45-degree angle relative to the runway centerline. The KLM first officer called “V1” most likely at the precise moment that his captain saw the Pan Am jet directly in front of him. The KLM captain instantaneously rotated, scraping the tail for a distance of 65 feet. Fully airborne, its nose gear narrowly passed over the Pan Am, but there was not enough clearance and the main landing gear slammed broadside against the Pan Am. The impact sheared off the fuselage, destroying the upper deck just behind the flight deck. Both aircraft caught fire. The KLM jet remained airborne for a few seconds before hitting the ground 150 meters past the crash site and then sliding another 300 meters on the runway. The aircraft violently burst into a raging inferno.
*Accident Survivability
A Total of 583 passengers and crew perished between both aircraft making it the most deadly accident in aviation history. There were 234 passengers and 14 crew on board KLM Flight 4805; none survived.
On Pan Am Flight 1736, there were 335 fatalities, including nine members of the cabin crew. There were 77 survivors, including the flight crew. The impact destroyed the first-class lounge on the upper deck, causing the lounge floor to collapse onto the first-class section in the main cabin. None of those in the first-class lounge survived. According to some survivors, the shock of impact was not excessively violent, leading them to believe that the cause of was an explosion.
Many of the Pan Am passengers who were seated on the right side of the aircraft were killed instantly from the initial impact. Dozens more, who were seated in the center and aft of the fuselage, survived the impact but became trapped by the twisted metal and debris and thus were unable to escape the spreading fire. There were reports of other passengers who survived the impact but who became incapacitated from shock and fell into catatonic states, unable to move from their seats and flee the burning aircraft.
*Analyses and Lessons Learned
Communication errors, a rushed departure, monitoring and challenging errors, and poor visibility proved a deadly combination of factors that culminated with a disaster of historic proportions. While individually these factors posed a threat to safety, the most critical error committed that day was when the KLM captain departed without takeoff clearance, in the fog, when he knew that under the unusual circumstances other aircraft would be back-taxing to the departure end of the runway.
The safety analyst believed it was possible that the KLM first officer who had only 95 hours in the 747, and who was flying with the KLM Chief 747 Instructor, may have become intimidated by the captain’s legendary status. Being new to the jet and crewed with someone so well-respected may have caused him to second guess the circumstances.
*Reference
“Subsecretaria de Aviacion Civil” Accident Report, 1978. ICAO Circular 153-AN/56. Shari Stamford Krause.
Tenerife Airport Disaster - Wikipedia
Assignment 1: A Case Study
The Tenerife Disaster, which happened over 30 years ago (see our feature for the 30th Anniversary on March 27, 2007), still attracts dozens of readers from all over the world, each and every day. Please do us a favor and let us know in the comments below, why you found this topic interesting and, more importantly, so we can continue to improve our coverage, does this article answer the questions you had about the disaster?
Tenerife disaster: Collision between KLM and PanAm Boeing 747's at Tenerife. Sunday, March 27, 1977.
Los Rodeos, Tenerife's North airport is, unfortunately, famous for the fateful accident which occurred on March 27, 1977, in which 583 people died when KLM and Pan Am 747s collided on a crowded, foggy runway in Tenerife, Canary Islands. The incident remains the world's worst aviation accident in history.
Many contributing factors, lead up to the crash, but the probable cause, cited by the Air Line Pilots Association (ALPA, 1978), was the KLM pilot taking off without takeoff clearance.
The wreckage of KLM Boeing 747 PH-BUFWhat happened on the Tenerife runway?
Quite simply put, the KLM attempted takeoff, even though the Pan Am was still on the runway and the KLM had not received clearance for takeoff. The Pan Am tried to get out of the way and the KLM tried to climb over, but the latter ended belly up after dragging it's tail on the ground. The lower fuselage of the KLM plane hit the upper fuselage of the Pan Am plane, ripping apart the center of the Pan Am jet nearly directly above the wing.
Pan Am 1736 ablaze after its collision with KLM 4805Whilst I have no intention of quoting chapter and verse - you can check all the background information I've used to write this summary, via the links cited below - here is quick rundown of the various possible contributing factors:
1. Neither plane should have been at Los Rodeos in the first place, which was not used to handling the traffic it had that day. They should have been in Gran Canaria, but a terrorist bomb attack by Canary Island separatists, The Canary Islands Independence Movement, closed the airport there.
2. There was fog with poor visibility at Los Rodeos. That didn't help anyone, least of all the Pan Am who was looking for a suitable exit off the runway. The one they had been advised to take, seems an impossible turn for a 747.
3. The pilot of the KLM, Captain van Zanten, their "top man", seems to have been in some considerable hurry to get going and appears to have held a level of authority that subordinates did not dare challenge with the necessary strength.
4. Analysis of the cockpit voice recorder (CVR) transcript showed that the KLM pilot was convinced that he had been cleared for takeoff, while the Tenerife control tower was certain that the KLM 747 was stationary at the end of the runway and awaiting takeoff clearance.
5. Reading the transcript of the radio transmissions, exchanges between the tower and the planes were ambiguous at best. One contributing factor to the accident at Tenerife was the involved parties’ use of non-standard phraseology during the critical moments leading up to the accident.
6. The crucial communication that might have prevented the KLM from taking off was lost in radio squelch. The congestion that results from using a single channel radiotelephone system can also lead to communications which are either missed or blocked by the transmissions of other users (Kerns, 1991, 1999). This problem of blocked transmissions was apparent in the runway collision at Tenerife in the Canary Islands, when the air traffic controller and the Pan Am pilot both tried to contact the KLM pilot at the same time.
Another article, from Wikipedia, which discusses the causes in more detail, also highlights one of the positive things to come out of the Tenerife air disaster: sweeping changes made to international airline regulations.
With no small amount of irony, commercial aviation is safer today because of that terrible day in 1977, because, "It was made a worldwide rule that all control towers and pilot crews had to use English standard phrases." Actually, I found it surprising that was introduced so recently. My father had trained RAF pilots in communications during WWII, but they would all have been British and probably flying Spitfires, i.e. men for whom standard English phrases were already their everyday language.
The other positive move, of course, was building Reina Sofia airport on the south of the island of Tenerife, which started operating in 1978. It was already under construction when the Pan Am/KLM crash occurred and, it should be highlighted, therefore, was not built merely out of the aftermath. Previously, passengers had faced a very rough two hour journey by coach from Los Rodeos to the south, so it was more a tourism concern to build the Reina Sofia airport.
My reason for researching this disaster in detail, is because I think that being aware of the facts takes away much of the fear - fear of the unknown - that can lead, ultimately, to a fear of flying. Fortunately, it is a fear I have never had.
In 1980, I had flown from London's Heathrow International Airport to New York's John F. Kennedy International Airport on a Pan Am Flight 103. Yes, the same flight that was blown up over Lockerbie in 1988. In fact, I am almost certain that we flew on the same plane, "Maid of the Seas", so, I am aware to a small extent of the feeling of "There, but for the grace of God, go I".
And, as with most information about Tenerife, there is more speculation, myth and legend published about this crash than there are plain, hard facts. Whilst I can't claim to know the full story either, I do hope to distinguish here between items that can be verified and those which cannot.
What is certain is that Tenerife doesn't have a specially dangerous airport and, in any case, if you are arriving on a tourist charter flight you are far more likely to come to the south airport, not the north one where the accident occurred.
Tenerife disaster: Collision between KLM and PanAm Boeing 747's at Tenerife. Sunday, March 27, 1977.
Los Rodeos, Tenerife's North airport is, unfortunately, famous for the fateful accident which occurred on March 27, 1977, in which 583 people died when KLM and Pan Am 747s collided on a crowded, foggy runway in Tenerife, Canary Islands. The incident remains the world's worst aviation accident in history.
Many contributing factors, lead up to the crash, but the probable cause, cited by the Air Line Pilots Association (ALPA, 1978), was the KLM pilot taking off without takeoff clearance.
The wreckage of KLM Boeing 747 PH-BUFWhat happened on the Tenerife runway?
Quite simply put, the KLM attempted takeoff, even though the Pan Am was still on the runway and the KLM had not received clearance for takeoff. The Pan Am tried to get out of the way and the KLM tried to climb over, but the latter ended belly up after dragging it's tail on the ground. The lower fuselage of the KLM plane hit the upper fuselage of the Pan Am plane, ripping apart the center of the Pan Am jet nearly directly above the wing.
Pan Am 1736 ablaze after its collision with KLM 4805Whilst I have no intention of quoting chapter and verse - you can check all the background information I've used to write this summary, via the links cited below - here is quick rundown of the various possible contributing factors:
1. Neither plane should have been at Los Rodeos in the first place, which was not used to handling the traffic it had that day. They should have been in Gran Canaria, but a terrorist bomb attack by Canary Island separatists, The Canary Islands Independence Movement, closed the airport there.
2. There was fog with poor visibility at Los Rodeos. That didn't help anyone, least of all the Pan Am who was looking for a suitable exit off the runway. The one they had been advised to take, seems an impossible turn for a 747.
3. The pilot of the KLM, Captain van Zanten, their "top man", seems to have been in some considerable hurry to get going and appears to have held a level of authority that subordinates did not dare challenge with the necessary strength.
4. Analysis of the cockpit voice recorder (CVR) transcript showed that the KLM pilot was convinced that he had been cleared for takeoff, while the Tenerife control tower was certain that the KLM 747 was stationary at the end of the runway and awaiting takeoff clearance.
5. Reading the transcript of the radio transmissions, exchanges between the tower and the planes were ambiguous at best. One contributing factor to the accident at Tenerife was the involved parties’ use of non-standard phraseology during the critical moments leading up to the accident.
6. The crucial communication that might have prevented the KLM from taking off was lost in radio squelch. The congestion that results from using a single channel radiotelephone system can also lead to communications which are either missed or blocked by the transmissions of other users (Kerns, 1991, 1999). This problem of blocked transmissions was apparent in the runway collision at Tenerife in the Canary Islands, when the air traffic controller and the Pan Am pilot both tried to contact the KLM pilot at the same time.
Another article, from Wikipedia, which discusses the causes in more detail, also highlights one of the positive things to come out of the Tenerife air disaster: sweeping changes made to international airline regulations.
With no small amount of irony, commercial aviation is safer today because of that terrible day in 1977, because, "It was made a worldwide rule that all control towers and pilot crews had to use English standard phrases." Actually, I found it surprising that was introduced so recently. My father had trained RAF pilots in communications during WWII, but they would all have been British and probably flying Spitfires, i.e. men for whom standard English phrases were already their everyday language.
The other positive move, of course, was building Reina Sofia airport on the south of the island of Tenerife, which started operating in 1978. It was already under construction when the Pan Am/KLM crash occurred and, it should be highlighted, therefore, was not built merely out of the aftermath. Previously, passengers had faced a very rough two hour journey by coach from Los Rodeos to the south, so it was more a tourism concern to build the Reina Sofia airport.
My reason for researching this disaster in detail, is because I think that being aware of the facts takes away much of the fear - fear of the unknown - that can lead, ultimately, to a fear of flying. Fortunately, it is a fear I have never had.
In 1980, I had flown from London's Heathrow International Airport to New York's John F. Kennedy International Airport on a Pan Am Flight 103. Yes, the same flight that was blown up over Lockerbie in 1988. In fact, I am almost certain that we flew on the same plane, "Maid of the Seas", so, I am aware to a small extent of the feeling of "There, but for the grace of God, go I".
And, as with most information about Tenerife, there is more speculation, myth and legend published about this crash than there are plain, hard facts. Whilst I can't claim to know the full story either, I do hope to distinguish here between items that can be verified and those which cannot.
What is certain is that Tenerife doesn't have a specially dangerous airport and, in any case, if you are arriving on a tourist charter flight you are far more likely to come to the south airport, not the north one where the accident occurred.
Caused Aviation Accidents: A Case Study 1
In the evolution of aviation safety it is often recognized that after an accident, accident investigators conduct exhaustive research in the cause of such accidents. Often, once a conclusion is reached, regulations are put in force to prevent such accidents from happening. There is one regulation, put forth by the ICAO that demands all aviators have a proficiency in the English language. This is to avoid confusion, aid in international flight operations, increase air commerce, and ensure a safer flight environment. What happens, then, if the cause of an accident is found because of this regulation? Language itself is the most complex skill humans can achieve—far beyond the difficulties of attainment of other knowledge areas (O'Grady, 2001) When discrepancies exist between any one who communicates, be it the pilots, the controllers, or even the airplane itself, misunderstanding can cause calamity and reform.
Language Confusion
In any language, the main goal is to be understood. In order for that to happen a source needs to encode a symbol, usually a spoken word, that can be decoded correctly by a receiver. Any language, whether English, mathematics, MySQL, or even whale whistles need to have symbols that have meaning. Spoken language, English for example, is a mixture of many registers that must all be decoded at once.
Phonetics is basically the study of 'noises and their meanings' Phonetics tells us that the 's,' 'z,' or 'ez,' sounds after a noun make the word a plural—or 'more than one'. Phonology tells us when to make one of these three sounds. 'horses' has a 'ez' sound because the 's' after the root is a alveolar fricative. The 'z' sound after bee is because the 'e' is voiced, and the 's' sound after 'front' is because the 't' is unvoiced.
Next, the morphology. Morphology tells us how to put phonemes together to create meaning. A word such as 'military' can turn into many other words depending on the affixes surrounding it.
ex. military—militarization—countermilitarization—demilitarization—pseudocounterdemiliterizationing—etc. Syntax tells us how to put these words together in a sentence in order to derive an even bigger meaning.
ex. Depending on how the enemies react, our military strategy should be successful in the demilitarization of their forces.
Finally, what does it all mean? Semantics helps us understand what a communicator means even though the sentence might seem to mean something else. This is most apparent in idiomatic expressions; where the sentence is different then the actual meaning.
Ex. “Take a bull by the horns” or “Hit the ground rolling”
Meaning: “Let's make sure we get started on this quickly, and thoroughly.”
So what happens then when there is a disconnect on any one of these registers? If there is an inability to decipher meaning in the smallest part of the language puzzle, then greater meaning will never be achieved. (O'Grady, 2001)
Polish Pilots
Recently a Lot Boeing 737 with ninety-three passengers aboard came within seconds of a midair collision. The plane was being piloted with two Polish-pilots who had not passed the English proficiency exam. The plane was flying into Heathrow Airport when the controllers had advised them with instructions after their instruments became unreliable. The pilots could not understand the controllers' instructions and often deviated from their vectors. Because of the Polish pilots' inability to understand clearly where they were in relationship to the airport, the controllers had to vector another plane instead in order to avoid a mid-air collision. In the final report by the Air Accidents Investigation Branch (AAIB) it states:
“The crew of Lot 282 were not able to communicate adequately the nature and extent of their problem . . .The commander, who was making the radio calls, was not able to understand some of the instructions . . . the initial error by the co-pilot . . .was compounded by the difficulty of obtaining information from the pilots because of their limited command of English ” (Ben Webster, 2008)
Tenerife
Often regarded as one of the worst aviation disasters in history involved the tragic deaths of hundreds, and the mad rush to regulation. On March 27, 1977 a PanAmerican 747-121 and a KLM 747-206B collided on the runway in low visibility. However, the cause of the accident is mostly blamed for the misunderstandings between ATC, and the pilots aboard the planes. When the KLM airplane was in position and holding, the co-pilot asked for a takeoff clearance. Air Traffic Control gave the clearance instructions, but never explicitly said they were cleared for take-off. When the co-pilot read back the clearance, he stated that they were now 'taking off' Again, without the explicit wording of 'cleared for takeoff' When the controller responded back with the words 'Okay' the pilots then regarded this as further clarification that an original clearance had been given. When KLM was on the takeoff roll, the PanAmerican plane and the controllers both radioed at the same time, canceling each other's calls that the KLM should not take off yet. KLM never heard the radio call and continued resulting in a crash that killed hundreds. (NTSB, 1978)
Once the investigations were completed, it was concluded that the most probable cause of the crash was the ambiguity of the English language that led the KLM pilots to believe that they were cleared to takeoff even without a clearance. The use of a non-standard phrase 'Okay' was the likely culprit in solidifying the KLM crew of their take-off clearance. Limited visibility, of course, was an issue, but was not the cause of the ambiguity. (Mell, 2001)
“The following must also be considered factors which contributed to the accident:
1.- Inadequate language. When the KLM Co-pilot repeated off the ATC clearance, he ended with the words, “we are now at take off”. The Controller, who had not been asked for take-off clearance, and had not granted it, did not understand that they were taking off. The O.K. From the tower, which preceded the “stand by for take-off” was likewise incorrect-although irrelevant in this case because take off had already started about six and a half seconds before” (NTSB, 1978, emphasis added)
Cause and Effect
Sweeping reform of international standardization took hold in a massive effort to keep ambiguity away from pilot/controller communications. Standard phrases and wordage became regulation. For example: 'Okay' is non-standard and now replaced by 'Roger'. This change was to disambiguate an affirmative instruction to be confused with an affirmative clearance. Explicitness in communication is the goal. 'Line-up and wait' is also non-standard and is now 'taxi into position and hold'. The 'hold' being emphasized. This was to bring a standardized term to mean 'don't take off until I say to.' A 'hold' instruction is now an affirmation that the plane is allowed to taxi onto the runway, but not allowed to take off. A clearance has not been issued.
'Take-off' is now a non-standard word and is now replaced by 'departure'. This is also to disambiguate the intentions of the pilot crew and ATC to prevent an airplane from 'taking-off' when it is really ready to 'depart'. Take-off is only used in the actual takeoff roll. While waiting, 'departure' is used.
While all accidents are tragic occurrences, some benefit is derived through standardization and reform. As unfortunate as the situations surrounding the evolution of flight safety is, it is also beneficial to effectively learn and study the causes in order to prevent a future tragedy. English as a standard can cause an accident insomuch as the pilots are deficient in the fluent communication. Stricter reform and standardization has resulted, but as the Polish example hints at, is not as centric as it needs to be yet.
Tenerife airport disaster
The Tenerife airport disaster in 1977 was a collision involving two Boeing 747 passenger aircraft on the runway of Los Rodeos Airport (now known as Tenerife North Airport) on the Spanish island of Tenerife, one of the Canary Islands. With 583 fatalities, the crash remains the deadliest accident in aviation history. All 248 aboard the fully-fuelled KLM Flight 4805 were killed. There were also 335 fatalities and 61 survivors from Pan Am Flight 1736, which was struck along its spine by the KLM's landing gear, under-belly and four engines. Rescue crews were unaware for over 20 minutes that the Pan Am aircraft was also involved in the accident, because of the heavy fog and the separation of the crippled aircraft following the collision.
The collision took place on March 27, 1977, at 17:06:56 local time. The aircraft were operating as Pan Am Flight 1736 (the Clipper Victor) under the command of Captain Victor Grubbs, and KLM Flight 4805 (the Rijn) under the command of Captain Jacob Veldhuyzen van Zanten. Taking off in heavy fog on the airport's only runway, the KLM flight crashed into the top of the Pan Am aircraft backtaxiing in the opposite direction. The Pan Am had followed the backtaxiing of the KLM aircraft, under the direction of air traffic control, and the KLM's flight crew had been aware of Pan Am backtaxiing behind them on the same runway. Despite lack of visual confirmation due to the fog the KLM captain thought that Pan Am had cleared the runway and so attempted to take off without further clearance to do so. Several other key factors contributed to the accident
1:Flight history
For both planes, Tenerife was an unscheduled stop. Their destination was Gran Canaria International Airport (also known as Las Palmas Airport), serving Las Palmas on the nearby island of Gran Canaria. Both are in the Canary Islands, an autonomous community of Spain located in the Atlantic Ocean off the west coast of Morocco.
Pan Am Flight 1736 had taken off from Los Angeles International Airport with an intermediate stop at New York's John F. Kennedy International Airport. The aircraft was a Boeing 747–121, registration N736PA. Of the 380 passengers, 14 had boarded in New York, where the crew was also changed. The new crew consisted of Captain Victor Grubbs, First Officer Robert Bragg, and Flight Engineer George Warns; there were 14 other crew members. The same aircraft had operated the inaugural 747 commercial flight on January 22, 1970.
KLM Flight 4805, a charter flight for Holland International Travel Group from the Netherlands, had taken off four hours before from Amsterdam Airport Schiphol. Its captain was Jacob Veldhuyzen van Zanten and the first officer was Klaas Meurs. The aircraft was a Boeing 747-206B, registration PH-BUF. The KLM jet had 14 crew members and 235 passengers, including 48 children and three infants. Most of the KLM passengers were Dutch; four Germans, two Austrians, and two Americans were also on the plane. After the aircraft landed at Tenerife, a Dutch tour guide named Robina van Lanschot, who lived on the island in Puerto de la Cruz and wanted to see her boyfriend that night, chose not to re-board the 747, leaving 234 passengers on board
2:Disaster
Following the tower's instructions, the KLM aircraft was cleared to backtaxi the full length of runway 30 and make a 180° turn to put the aircraft in takeoff position — a difficult maneuver to perform with a 747 on a 45 m (150 ft) wide runway. While KLM 4805 was backtaxiing on runway 30, the controller asked the flight crew to report when it was ready to copy the ATC clearance. Because the flight crew was performing the checklist, copying this clearance was postponed until the aircraft was in takeoff position on Runway 30. During taxiing, the weather deteriorated and low-lying clouds now limited the visual range to about 300 m (1,000 ft). Legal or stipulated threshold for takeoff was 700 m (2,300 ft) visibility, as noted in the NOVA documentary and relayed by surviving Pan Am co-pilot Robert Bragg.
Shortly afterward, Pan Am 1736 was instructed to also backtaxi, to follow the KLM aircraft down the same runway, to exit the runway by taking the "third exit" on their left and then using the parallel taxiway. Initially the crew was unclear as to whether the controller had told them to take the first or third exit. The crew asked for clarification and the controller responded emphatically by replying: "The third one, sir; one, two, three; third, third one". The crew began the taxi and proceeded to identify the unmarked taxiways using an airport diagram as they reached them.
Based on the chronology of the cockpit voice recorder (CVR) and the distances between the taxiways (and the location of the aircraft at the time of the collision), the crew successfully identified the first two taxiways (C-1 and C-2), but their discussion in the cockpit never indicated that they had sighted the third taxiway (C-3), which they had been instructed to use. There were no markings or signs to identify the runway exits. The Pan Am crew appeared to remain unsure of their position on the runway until the collision, which occurred near the intersection with the fourth taxiway (C-4). Pan Am's lack of visibility and runway exiting confusion probably contributed to its slow taxiing speed, another key factor in the accident.
The angle of the third taxiway would have required the plane to perform a turn of approximately 145°, which would lead counter-productively back toward the still-crowded main apron. At the end of C-3 another 145° turn would have to be made to continue taxiing towards the start of the runway. Taxiway C-4 would have required just two 35° turns. A study carried out by the Air Line Pilots Association after the accident concluded that making the second 145° turn at the end of taxiway C-3 would have been "a practical impossibility", although the Dutch report stated that such a maneuver "could reasonably be performed". The official report from the Spanish authorities did not explain why the controller had instructed the Pan Am aircraft to use the third taxiway, rather than the sensible and easier fourth taxiway
3:Communication misunderstandings
Immediately after lining up, the KLM captain advanced the throttles (a standard procedure known as "spin-up", to verify that the engines are operating properly for takeoff) and co-pilot Meurs, surprised by the maneuver, quickly advised the captain that ATC clearance had not yet been given. Captain Van Zanten responded, "I know that. Go ahead, ask." Meurs then radioed the tower that they were "ready for takeoff" and "waiting for our ATC clearance". The KLM crew then received instructions which specified the route that the aircraft was to follow after takeoff. The instructions used the word "takeoff," but did not include an explicit statement that they were cleared for takeoff.
Meurs read the flight clearance back to the controller, completing the readback with the statement "we're now at takeoff" or "we're now, uh, taking off" (the exact wording of his statement was not clear[citation needed]), indicating to the controller that they were beginning their takeoff roll. Captain Van Zanten interrupted the co-pilot's readback with the comment "We're going". As noted in the NOVA documentary, Meurs chose not to embarrass his superior a second time by stating that they still did not have the proper clearance to take off.
The Spanish controller, who could not see the runway due to the fog, initially responded with "OK" (terminology which is nonstandard), which reinforced the KLM captain's misinterpretation that they had takeoff clearance. The controller's response of "OK" to the co-pilot's nonstandard statement that they were "now at takeoff" was likely due to his misinterpretation that they were in takeoff position and ready to begin the roll when takeoff clearance was received, but not actually in the process of taking off. The controller then immediately added "stand by for takeoff, I will call you", indicating that he had not intended the clearance to be interpreted as a takeoff clearance. He probably had not heard the captain's announcement that they were "going," since Van Zanten had said this to his fellow crew members and not transmitted it on the radio himself.
A simultaneous radio call from the Pan Am crew caused mutual interference on the radio frequency, which was audible in the KLM cockpit as a whistling sound (or heterodyne). This made the crucial latter portion of the tower's response audible only with difficulty by the KLM crew. The Pan Am crew's transmission, which was also critical, was reporting that "We're still taxiing down the runway, the Clipper 1736!" This message was also blocked by the heterodyne and inaudible to the KLM crew. Either message, if heard in the KLM cockpit, would have given the KLM crew time to abort its second takeoff attempt.
Due to the fog, neither crew was able to see the other plane on the runway ahead of them. In addition, neither of the aircraft could be seen from the control tower, and the airport was not equipped with ground radar.
After the KLM plane had started its takeoff roll, the tower instructed the Pan Am crew to "report when runway clear." The crew replied: "OK, we'll report when we're clear." On hearing this, flight engineer Willem Schreuder expressed his concern about the Pan Am not being clear of the runway by asking the pilots, "Is he not clear, that Pan American?" Van Zanten emphatically replied "Oh, yes" and continued with the takeoff
4:Collision
According to the CVR, Captain Grubbs, captain of the Pan Am plane, spotted the KLM's landing lights just as the plane approached exit C-4, exclaiming, "Goddamn, that son-of-a-bitch is coming straight at us!" with the co-pilot Robert Bragg yelling, "Get off! Get off! Get off!". The Pan Am crew applied full power and took a sharp left turn towards the exit to avoid a collision. KLM Captain Van Zanten attempted to avoid a collision by climbing away, scraping the tail of the plane along the runway for 20 m (66 ft). As the KLM left the ground its steep angle of attack allowed the nose gear to clear the Pan Am but the lower fuselage and aft landing gears struck the upper right side of the Pan Am's fuselage at approximately 140 knots (260 km/h; 160 mph),[2] ripping apart the center of the Pan Am jet almost directly above the wing, and its right engines crashed through Pan Am's upper-deck passenger cabin, immediately behind the cockpit.
The KLM plane was briefly airborne, but the impact with the Pan Am had sheared off the #1 (outer left) engine, and the #2 (inner left) engine had ingested significant amounts of shredded materials from the Pan Am. The KLM pilot quickly lost control, and the 747 went into a stall, rolled sharply, slammed into the ground at a point 150 m (500 ft) past the collision and slid a further 300 m down the runway. As the jet was fully fuelled, a deadly fuel-air explosion ensued.
A survivor of the Pan Am flight, John Coombs of Haleiwa, Hawaii, said that sitting in the nose of the plane probably saved his life: "We all settled back, and the next thing an explosion took place and the whole port side, left side of the plane, was just torn wide open."
Both airplanes were destroyed. All 234 passengers and 14 crew members in the KLM plane died, while 326 passengers and 9 crew members aboard the Pan Am flight were also killed,[9] primarily due to the fire and explosions resulting from the fuel spilled and ignited in the impact. The other 56 passengers and 5 crew members aboard the Pan Am aircraft survived, including the captain, first officer, and flight engineer. Most of the survivors on the Pan Am aircraft walked out onto the left wing, the side away from the collision, through holes in the fuselage structure. The Pan Am's engines were still running at takeoff power for a few minutes after the accident despite First Officer Bragg's intention to turn them off. The top part of the cockpit, where the engine switches were located, had been destroyed in the collision. After a short time running at full power the Pan-Am's engines began to disintegrate, throwing engine parts at high speed that killed a flight attendant who had escaped the burning plane. Survivors waited for rescue, but it did not come promptly as the firefighters were initially unaware that there were two aircraft involved and were concentrating on the KLM wreck some distance away in the thick fog. Eventually, most of the survivors on the wings dropped to the ground below.
Captain Veldhuyzen van Zanten was KLM's chief of flight training and the airline's preferred pilot for publicity such as magazine advertisements. As such, KLM attempted to contact him to give public statements regarding the disaster, before learning that he was the captain involved. Veldhuyzen van Zanten had given Klaas Meurs, the first officer on the ill-fated flight, his Boeing 747 qualification check about two months before the accident.
5:Investigation
About70 crash investigators from Spain, the Netherlands, the United States, and the two airline companies were involved in the investigation. Facts showed that there had been misinterpretations and false assumptions. Analysis of the CVR transcript showed that the KLM pilot was convinced that he had been cleared for takeoff, while the Tenerife control tower was certain that the KLM 747 was stationary at the end of the runway and awaiting takeoff clearance. It appears KLM's co-pilot was not as certain about take-off clearance as the captain.
Subsequent to the crash, first officer Robert Bragg, who was responsible for handling the Pan Am's radio communications, made public statements which conflict with statements made by the Pan Am crew in the official transcript of the CVR. In the documentary Crash of the Century (produced by the makers of Mayday), he stated he was convinced the tower controller had intended they take the fourth exit C-4 because the controller delivered the message to take "the third one, sir, one; two, three; third, third one" after the Pan Am's had already passed C-1 (making C-4 the third exit counting from there). The CVR shows unequivocally that they received this message before they identified C-1, with the position of the aircraft somewhere between the entrance and C-1. Also, in a Time article, Bragg stated that he made the statement "What's he doing? He'll kill us all!" which does not appear in the CVR transcript
6:Probable cause
The investigation concluded that the fundamental cause of the accident was that Captain Van Zanten took off without takeoff clearance. The investigators suggested the reason for his mistake might have been a desire to leave as soon as possible in order to comply with KLM's duty-time regulations, and before the weather deteriorated further.
Other major factors contributing to the accident were:
*The sudden fog greatly limited visibility. The control tower and the crews of both planes were unable to see one another.
*Simultaneous radio transmissions, with the result that neither message could be heard.
The following factors were considered contributing but not critical:
*Use of ambiguous non-standard phrases by the KLM co-pilot ("We're at take off") and the Tenerife control tower ("OK").
*Pan Am mistakenly continued to exit C-4 instead of exiting at C-3 as directed.
*The airport was (due to rerouting from the bomb threat) forced to accommodate a great number of large aircraft, resulting in disruption of the normal use of taxiways.
7:Responsibility
Although the Dutch authorities were initially reluctant to blame Captain Van Zanten and his crew,the airline ultimately accepted responsibility for the accident. KLM paid the victims or their families compensation ranging between $58,000 and $600,000. As reported in a March 25, 1980, Washington Post article the sum of settlements for property and damages was $110 million (an average of $189,000 per victim, due to limitations imposed by European Compensation Conventions in effect at the time)
8:Safety response
As a consequence of the accident, sweeping changes were made to international airline regulations and to aircraft. Aviation authorities around the world introduced requirements for standard phrases and a greater emphasis on English as a common working language. For example, ICAO calls for the phrase "line up and wait" as an instruction to an aircraft moving into position but not cleared for takeoff. The FAA equivalent at the time was "position and hold" (though as of September 30, 2010, this has been changed to "line up and wait" to comply with ICAO standards). Also several national air safety boards began penalizing pilots for disobeying air traffic controller's orders. Air traffic instruction should not be acknowledged solely with a colloquial phrase such as "OK" or even "Roger", but with a readback of the key parts of the instruction, to show mutual understanding. Additionally, the phrase "takeoff" is only spoken when the actual takeoff clearance is given. Up until that point, both aircrew and controllers should use the phrase "departure" in its place (e.g. "ready for departure"). Cockpit procedures were also changed. Hierarchical relations among crew members were played down. More emphasis was placed on team decision-making by mutual agreement. This is known in the industry as Crew Resource Management.
In 1978 a second airport was inaugurated on the island: the new Tenerife South Airport (TFS). This airport now serves the majority of international tourist flights. Los Rodeos, renamed to Tenerife North Airport (TFN), was then used only for domestic and inter-island flights, but in 2002 a new terminal was opened and it carries international traffic once again, including budget airlines. The Spanish authorities installed a ground radar at Tenerife North following the accident.
References
^ Fatal Events Since 1970 for KLM AirSafe.com
^ Kilroy, Chris Special Report: Tenerife AirDisaster.com
The collision took place on March 27, 1977, at 17:06:56 local time. The aircraft were operating as Pan Am Flight 1736 (the Clipper Victor) under the command of Captain Victor Grubbs, and KLM Flight 4805 (the Rijn) under the command of Captain Jacob Veldhuyzen van Zanten. Taking off in heavy fog on the airport's only runway, the KLM flight crashed into the top of the Pan Am aircraft backtaxiing in the opposite direction. The Pan Am had followed the backtaxiing of the KLM aircraft, under the direction of air traffic control, and the KLM's flight crew had been aware of Pan Am backtaxiing behind them on the same runway. Despite lack of visual confirmation due to the fog the KLM captain thought that Pan Am had cleared the runway and so attempted to take off without further clearance to do so. Several other key factors contributed to the accident
1:Flight history
For both planes, Tenerife was an unscheduled stop. Their destination was Gran Canaria International Airport (also known as Las Palmas Airport), serving Las Palmas on the nearby island of Gran Canaria. Both are in the Canary Islands, an autonomous community of Spain located in the Atlantic Ocean off the west coast of Morocco.
Pan Am Flight 1736 had taken off from Los Angeles International Airport with an intermediate stop at New York's John F. Kennedy International Airport. The aircraft was a Boeing 747–121, registration N736PA. Of the 380 passengers, 14 had boarded in New York, where the crew was also changed. The new crew consisted of Captain Victor Grubbs, First Officer Robert Bragg, and Flight Engineer George Warns; there were 14 other crew members. The same aircraft had operated the inaugural 747 commercial flight on January 22, 1970.
KLM Flight 4805, a charter flight for Holland International Travel Group from the Netherlands, had taken off four hours before from Amsterdam Airport Schiphol. Its captain was Jacob Veldhuyzen van Zanten and the first officer was Klaas Meurs. The aircraft was a Boeing 747-206B, registration PH-BUF. The KLM jet had 14 crew members and 235 passengers, including 48 children and three infants. Most of the KLM passengers were Dutch; four Germans, two Austrians, and two Americans were also on the plane. After the aircraft landed at Tenerife, a Dutch tour guide named Robina van Lanschot, who lived on the island in Puerto de la Cruz and wanted to see her boyfriend that night, chose not to re-board the 747, leaving 234 passengers on board
2:Disaster
Following the tower's instructions, the KLM aircraft was cleared to backtaxi the full length of runway 30 and make a 180° turn to put the aircraft in takeoff position — a difficult maneuver to perform with a 747 on a 45 m (150 ft) wide runway. While KLM 4805 was backtaxiing on runway 30, the controller asked the flight crew to report when it was ready to copy the ATC clearance. Because the flight crew was performing the checklist, copying this clearance was postponed until the aircraft was in takeoff position on Runway 30. During taxiing, the weather deteriorated and low-lying clouds now limited the visual range to about 300 m (1,000 ft). Legal or stipulated threshold for takeoff was 700 m (2,300 ft) visibility, as noted in the NOVA documentary and relayed by surviving Pan Am co-pilot Robert Bragg.
Shortly afterward, Pan Am 1736 was instructed to also backtaxi, to follow the KLM aircraft down the same runway, to exit the runway by taking the "third exit" on their left and then using the parallel taxiway. Initially the crew was unclear as to whether the controller had told them to take the first or third exit. The crew asked for clarification and the controller responded emphatically by replying: "The third one, sir; one, two, three; third, third one". The crew began the taxi and proceeded to identify the unmarked taxiways using an airport diagram as they reached them.
Based on the chronology of the cockpit voice recorder (CVR) and the distances between the taxiways (and the location of the aircraft at the time of the collision), the crew successfully identified the first two taxiways (C-1 and C-2), but their discussion in the cockpit never indicated that they had sighted the third taxiway (C-3), which they had been instructed to use. There were no markings or signs to identify the runway exits. The Pan Am crew appeared to remain unsure of their position on the runway until the collision, which occurred near the intersection with the fourth taxiway (C-4). Pan Am's lack of visibility and runway exiting confusion probably contributed to its slow taxiing speed, another key factor in the accident.
The angle of the third taxiway would have required the plane to perform a turn of approximately 145°, which would lead counter-productively back toward the still-crowded main apron. At the end of C-3 another 145° turn would have to be made to continue taxiing towards the start of the runway. Taxiway C-4 would have required just two 35° turns. A study carried out by the Air Line Pilots Association after the accident concluded that making the second 145° turn at the end of taxiway C-3 would have been "a practical impossibility", although the Dutch report stated that such a maneuver "could reasonably be performed". The official report from the Spanish authorities did not explain why the controller had instructed the Pan Am aircraft to use the third taxiway, rather than the sensible and easier fourth taxiway
3:Communication misunderstandings
Immediately after lining up, the KLM captain advanced the throttles (a standard procedure known as "spin-up", to verify that the engines are operating properly for takeoff) and co-pilot Meurs, surprised by the maneuver, quickly advised the captain that ATC clearance had not yet been given. Captain Van Zanten responded, "I know that. Go ahead, ask." Meurs then radioed the tower that they were "ready for takeoff" and "waiting for our ATC clearance". The KLM crew then received instructions which specified the route that the aircraft was to follow after takeoff. The instructions used the word "takeoff," but did not include an explicit statement that they were cleared for takeoff.
Meurs read the flight clearance back to the controller, completing the readback with the statement "we're now at takeoff" or "we're now, uh, taking off" (the exact wording of his statement was not clear[citation needed]), indicating to the controller that they were beginning their takeoff roll. Captain Van Zanten interrupted the co-pilot's readback with the comment "We're going". As noted in the NOVA documentary, Meurs chose not to embarrass his superior a second time by stating that they still did not have the proper clearance to take off.
The Spanish controller, who could not see the runway due to the fog, initially responded with "OK" (terminology which is nonstandard), which reinforced the KLM captain's misinterpretation that they had takeoff clearance. The controller's response of "OK" to the co-pilot's nonstandard statement that they were "now at takeoff" was likely due to his misinterpretation that they were in takeoff position and ready to begin the roll when takeoff clearance was received, but not actually in the process of taking off. The controller then immediately added "stand by for takeoff, I will call you", indicating that he had not intended the clearance to be interpreted as a takeoff clearance. He probably had not heard the captain's announcement that they were "going," since Van Zanten had said this to his fellow crew members and not transmitted it on the radio himself.
A simultaneous radio call from the Pan Am crew caused mutual interference on the radio frequency, which was audible in the KLM cockpit as a whistling sound (or heterodyne). This made the crucial latter portion of the tower's response audible only with difficulty by the KLM crew. The Pan Am crew's transmission, which was also critical, was reporting that "We're still taxiing down the runway, the Clipper 1736!" This message was also blocked by the heterodyne and inaudible to the KLM crew. Either message, if heard in the KLM cockpit, would have given the KLM crew time to abort its second takeoff attempt.
Due to the fog, neither crew was able to see the other plane on the runway ahead of them. In addition, neither of the aircraft could be seen from the control tower, and the airport was not equipped with ground radar.
After the KLM plane had started its takeoff roll, the tower instructed the Pan Am crew to "report when runway clear." The crew replied: "OK, we'll report when we're clear." On hearing this, flight engineer Willem Schreuder expressed his concern about the Pan Am not being clear of the runway by asking the pilots, "Is he not clear, that Pan American?" Van Zanten emphatically replied "Oh, yes" and continued with the takeoff
4:Collision
According to the CVR, Captain Grubbs, captain of the Pan Am plane, spotted the KLM's landing lights just as the plane approached exit C-4, exclaiming, "Goddamn, that son-of-a-bitch is coming straight at us!" with the co-pilot Robert Bragg yelling, "Get off! Get off! Get off!". The Pan Am crew applied full power and took a sharp left turn towards the exit to avoid a collision. KLM Captain Van Zanten attempted to avoid a collision by climbing away, scraping the tail of the plane along the runway for 20 m (66 ft). As the KLM left the ground its steep angle of attack allowed the nose gear to clear the Pan Am but the lower fuselage and aft landing gears struck the upper right side of the Pan Am's fuselage at approximately 140 knots (260 km/h; 160 mph),[2] ripping apart the center of the Pan Am jet almost directly above the wing, and its right engines crashed through Pan Am's upper-deck passenger cabin, immediately behind the cockpit.
The KLM plane was briefly airborne, but the impact with the Pan Am had sheared off the #1 (outer left) engine, and the #2 (inner left) engine had ingested significant amounts of shredded materials from the Pan Am. The KLM pilot quickly lost control, and the 747 went into a stall, rolled sharply, slammed into the ground at a point 150 m (500 ft) past the collision and slid a further 300 m down the runway. As the jet was fully fuelled, a deadly fuel-air explosion ensued.
A survivor of the Pan Am flight, John Coombs of Haleiwa, Hawaii, said that sitting in the nose of the plane probably saved his life: "We all settled back, and the next thing an explosion took place and the whole port side, left side of the plane, was just torn wide open."
Both airplanes were destroyed. All 234 passengers and 14 crew members in the KLM plane died, while 326 passengers and 9 crew members aboard the Pan Am flight were also killed,[9] primarily due to the fire and explosions resulting from the fuel spilled and ignited in the impact. The other 56 passengers and 5 crew members aboard the Pan Am aircraft survived, including the captain, first officer, and flight engineer. Most of the survivors on the Pan Am aircraft walked out onto the left wing, the side away from the collision, through holes in the fuselage structure. The Pan Am's engines were still running at takeoff power for a few minutes after the accident despite First Officer Bragg's intention to turn them off. The top part of the cockpit, where the engine switches were located, had been destroyed in the collision. After a short time running at full power the Pan-Am's engines began to disintegrate, throwing engine parts at high speed that killed a flight attendant who had escaped the burning plane. Survivors waited for rescue, but it did not come promptly as the firefighters were initially unaware that there were two aircraft involved and were concentrating on the KLM wreck some distance away in the thick fog. Eventually, most of the survivors on the wings dropped to the ground below.
Captain Veldhuyzen van Zanten was KLM's chief of flight training and the airline's preferred pilot for publicity such as magazine advertisements. As such, KLM attempted to contact him to give public statements regarding the disaster, before learning that he was the captain involved. Veldhuyzen van Zanten had given Klaas Meurs, the first officer on the ill-fated flight, his Boeing 747 qualification check about two months before the accident.
5:Investigation
About70 crash investigators from Spain, the Netherlands, the United States, and the two airline companies were involved in the investigation. Facts showed that there had been misinterpretations and false assumptions. Analysis of the CVR transcript showed that the KLM pilot was convinced that he had been cleared for takeoff, while the Tenerife control tower was certain that the KLM 747 was stationary at the end of the runway and awaiting takeoff clearance. It appears KLM's co-pilot was not as certain about take-off clearance as the captain.
Subsequent to the crash, first officer Robert Bragg, who was responsible for handling the Pan Am's radio communications, made public statements which conflict with statements made by the Pan Am crew in the official transcript of the CVR. In the documentary Crash of the Century (produced by the makers of Mayday), he stated he was convinced the tower controller had intended they take the fourth exit C-4 because the controller delivered the message to take "the third one, sir, one; two, three; third, third one" after the Pan Am's had already passed C-1 (making C-4 the third exit counting from there). The CVR shows unequivocally that they received this message before they identified C-1, with the position of the aircraft somewhere between the entrance and C-1. Also, in a Time article, Bragg stated that he made the statement "What's he doing? He'll kill us all!" which does not appear in the CVR transcript
6:Probable cause
The investigation concluded that the fundamental cause of the accident was that Captain Van Zanten took off without takeoff clearance. The investigators suggested the reason for his mistake might have been a desire to leave as soon as possible in order to comply with KLM's duty-time regulations, and before the weather deteriorated further.
Other major factors contributing to the accident were:
*The sudden fog greatly limited visibility. The control tower and the crews of both planes were unable to see one another.
*Simultaneous radio transmissions, with the result that neither message could be heard.
The following factors were considered contributing but not critical:
*Use of ambiguous non-standard phrases by the KLM co-pilot ("We're at take off") and the Tenerife control tower ("OK").
*Pan Am mistakenly continued to exit C-4 instead of exiting at C-3 as directed.
*The airport was (due to rerouting from the bomb threat) forced to accommodate a great number of large aircraft, resulting in disruption of the normal use of taxiways.
7:Responsibility
Although the Dutch authorities were initially reluctant to blame Captain Van Zanten and his crew,the airline ultimately accepted responsibility for the accident. KLM paid the victims or their families compensation ranging between $58,000 and $600,000. As reported in a March 25, 1980, Washington Post article the sum of settlements for property and damages was $110 million (an average of $189,000 per victim, due to limitations imposed by European Compensation Conventions in effect at the time)
8:Safety response
As a consequence of the accident, sweeping changes were made to international airline regulations and to aircraft. Aviation authorities around the world introduced requirements for standard phrases and a greater emphasis on English as a common working language. For example, ICAO calls for the phrase "line up and wait" as an instruction to an aircraft moving into position but not cleared for takeoff. The FAA equivalent at the time was "position and hold" (though as of September 30, 2010, this has been changed to "line up and wait" to comply with ICAO standards). Also several national air safety boards began penalizing pilots for disobeying air traffic controller's orders. Air traffic instruction should not be acknowledged solely with a colloquial phrase such as "OK" or even "Roger", but with a readback of the key parts of the instruction, to show mutual understanding. Additionally, the phrase "takeoff" is only spoken when the actual takeoff clearance is given. Up until that point, both aircrew and controllers should use the phrase "departure" in its place (e.g. "ready for departure"). Cockpit procedures were also changed. Hierarchical relations among crew members were played down. More emphasis was placed on team decision-making by mutual agreement. This is known in the industry as Crew Resource Management.
In 1978 a second airport was inaugurated on the island: the new Tenerife South Airport (TFS). This airport now serves the majority of international tourist flights. Los Rodeos, renamed to Tenerife North Airport (TFN), was then used only for domestic and inter-island flights, but in 2002 a new terminal was opened and it carries international traffic once again, including budget airlines. The Spanish authorities installed a ground radar at Tenerife North following the accident.
References
^ Fatal Events Since 1970 for KLM AirSafe.com
^ Kilroy, Chris Special Report: Tenerife AirDisaster.com
Tenerife airport disaster
The Tenerife airport disaster in 1977 was a collision involving two Boeing 747 passenger aircraft on the runway of Los Rodeos Airport (now known as Tenerife North Airport) on the Spanish island of Tenerife, one of the Canary Islands. With 583 fatalities, the crash remains the deadliest accident in aviation history. All 248 aboard the fully-fuelled KLM Flight 4805 were killed. There were also 335 fatalities and 61 survivors from Pan Am Flight 1736, which was struck along its spine by the KLM's landing gear, under-belly and four engines. Rescue crews were unaware for over 20 minutes that the Pan Am aircraft was also involved in the accident, because of the heavy fog and the separation of the crippled aircraft following the collision.
The collision took place on March 27, 1977, at 17:06:56 local time. The aircraft were operating as Pan Am Flight 1736 (the Clipper Victor) under the command of Captain Victor Grubbs, and KLM Flight 4805 (the Rijn) under the command of Captain Jacob Veldhuyzen van Zanten. Taking off in heavy fog on the airport's only runway, the KLM flight crashed into the top of the Pan Am aircraft backtaxiing in the opposite direction. The Pan Am had followed the backtaxiing of the KLM aircraft, under the direction of air traffic control, and the KLM's flight crew had been aware of Pan Am backtaxiing behind them on the same runway. Despite lack of visual confirmation due to the fog the KLM captain thought that Pan Am had cleared the runway and so attempted to take off without further clearance to do so. Several other key factors contributed to the accident.
[edit] Flight historyFor both planes, Tenerife was an unscheduled stop. Their destination was Gran Canaria International Airport (also known as Las Palmas Airport), serving Las Palmas on the nearby island of Gran Canaria. Both are in the Canary Islands, an autonomous community of Spain located in the Atlantic Ocean off the west coast of Morocco.
Pan Am Flight 1736 had taken off from Los Angeles International Airport with an intermediate stop at New York's John F. Kennedy International Airport. The aircraft was a Boeing 747–121, registration N736PA. Of the 380 passengers, 14 had boarded in New York, where the crew was also changed. The new crew consisted of Captain Victor Grubbs, First Officer Robert Bragg, and Flight Engineer George Warns; there were 14 other crew members. The same aircraft had operated the inaugural 747 commercial flight on January 22, 1970.[1]
KLM Flight 4805, a charter flight for Holland International Travel Group from the Netherlands,[1] had taken off four hours before from Amsterdam Airport Schiphol. Its captain was Jacob Veldhuyzen van Zanten and the first officer was Klaas Meurs. The aircraft was a Boeing 747-206B, registration PH-BUF. The KLM jet had 14 crew members and 235 passengers, including 48 children and three infants. Most of the KLM passengers were Dutch; four Germans, two Austrians, and two Americans were also on the plane. After the aircraft landed at Tenerife, a Dutch tour guide named Robina van Lanschot, who lived on the island in Puerto de la Cruz and wanted to see her boyfriend that night, chose not to re-board the 747, leaving 234 passengers on board.[2][3]
Disaster[edit] Bombing at Las PalmasEvents on both planes had been routine until they approached the islands. Then, at 1:15 pm, a terrorist bomb (planted by separatist Fuerzas Armadas Guanches) exploded in the terminal of Gran Canaria International Airport.[4] It had been preceded by a phone call warning of the bomb. The civil aviation authorities closed that airport after the bomb detonated and diverted all of its incoming flights to Los Rodeos, including the two Boeing 747 aircraft involved in the disaster. Upon contacting Gran Canaria airport, the Pan Am flight was informed of the temporary closure. Although the Pan Am crew indicated that they would prefer to circle in a holding pattern until landing clearance was given, the plane was ordered to divert to Los Rodeos, along with the KLM flight. This led to the critical cramped aircraft conditions within the smaller airport.[5]
Congestion at Los RodeosIn all, at least five large aircraft were diverted to Los Rodeos, a regional airport that could not easily accommodate them. The airport consisted of one runway and one major taxiway parallel to it, as well as several small taxiways connecting the main taxiway and the runway. While waiting for Gran Canaria airport to reopen, the diverted aircraft took up so much space that they were parked on the long taxiway, meaning that it could not be used for taxiing. Instead, departing aircraft would have to taxi along the runway to position themselves for takeoff, a procedure known as a runway backtaxi.
RefuellingAfter the threat at Gran Canaria International Airport had been contained, authorities reopened the airport. The Pan Am aircraft was ready to depart, but the KLM plane and a refuelling vehicle obstructed the way to the active runway. The Pan Am aircraft was unable to maneuver around the fueling KLM, reach the runway and depart due to a lack of just 12 ft (3.7 m) of clearance.[2] Captain Van Zanten had decided to fully refuel at Los Rodeos instead of Las Palmas, apparently to save time, but by doing so he added extra weight, greatly retarding liftoff (and accident escape) ability, which proved fatal. The refuelling took about 35 minutes.
Taxiing and weather conditions This section needs additional citations for verification.
Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (January 2011)
Following the tower's instructions, the KLM aircraft was cleared to backtaxi the full length of runway 30 and make a 180° turn to put the aircraft in takeoff position — a difficult maneuver to perform with a 747 on a 45 m (150 ft) wide runway. While KLM 4805 was backtaxiing on runway 30, the controller asked the flight crew to report when it was ready to copy the ATC clearance. Because the flight crew was performing the checklist, copying this clearance was postponed until the aircraft was in takeoff position on Runway 30. During taxiing, the weather deteriorated and low-lying clouds now limited the visual range to about 300 m (1,000 ft). Legal or stipulated threshold for takeoff was 700 m (2,300 ft) visibility, as noted in the NOVA documentary and relayed by surviving Pan Am co-pilot Robert Bragg.
Shortly afterward, Pan Am 1736 was instructed to also backtaxi, to follow the KLM aircraft down the same runway, to exit the runway by taking the "third exit" on their left and then using the parallel taxiway. Initially the crew was unclear as to whether the controller had told them to take the first or third exit. The crew asked for clarification and the controller responded emphatically by replying: "The third one, sir; one, two, three; third, third one". The crew began the taxi and proceeded to identify the unmarked taxiways using an airport diagram as they reached them.
Based on the chronology of the cockpit voice recorder (CVR) and the distances between the taxiways (and the location of the aircraft at the time of the collision), the crew successfully identified the first two taxiways (C-1 and C-2), but their discussion in the cockpit never indicated that they had sighted the third taxiway (C-3), which they had been instructed to use. There were no markings or signs to identify the runway exits. The Pan Am crew appeared to remain unsure of their position on the runway until the collision, which occurred near the intersection with the fourth taxiway (C-4). Pan Am's lack of visibility and runway exiting confusion probably contributed to its slow taxiing speed, another key factor in the accident.
The angle of the third taxiway would have required the plane to perform a turn of approximately 145°, which would lead counter-productively back toward the still-crowded main apron. At the end of C-3 another 145° turn would have to be made to continue taxiing towards the start of the runway. Taxiway C-4 would have required just two 35° turns. A study carried out by the Air Line Pilots Association after the accident concluded that making the second 145° turn at the end of taxiway C-3 would have been "a practical impossibility", although the Dutch report stated that such a maneuver "could reasonably be performed". The official report from the Spanish authorities did not explain why the controller had instructed the Pan Am aircraft to use the third taxiway, rather than the sensible and easier fourth taxiway.[6]
Communication misunderstandingsImmediately after lining up, the KLM captain advanced the throttles (a standard procedure known as "spin-up", to verify that the engines are operating properly for takeoff) and co-pilot Meurs, surprised by the maneuver, quickly advised the captain that ATC clearance had not yet been given. Captain Van Zanten responded, "I know that. Go ahead, ask." Meurs then radioed the tower that they were "ready for takeoff" and "waiting for our ATC clearance". The KLM crew then received instructions which specified the route that the aircraft was to follow after takeoff. The instructions used the word "takeoff," but did not include an explicit statement that they were cleared for takeoff.
Meurs read the flight clearance back to the controller, completing the readback with the statement "we're now at takeoff" or "we're now, uh, taking off" (the exact wording of his statement was not clear[citation needed]), indicating to the controller that they were beginning their takeoff roll. Captain Van Zanten interrupted the co-pilot's readback with the comment "We're going". As noted in the NOVA documentary, Meurs chose not to embarrass his superior a second time by stating that they still did not have the proper clearance to take off.
The Spanish controller, who could not see the runway due to the fog, initially responded with "OK" (terminology which is nonstandard), which reinforced the KLM captain's misinterpretation that they had takeoff clearance. The controller's response of "OK" to the co-pilot's nonstandard statement that they were "now at takeoff" was likely due to his misinterpretation that they were in takeoff position and ready to begin the roll when takeoff clearance was received, but not actually in the process of taking off. The controller then immediately added "stand by for takeoff, I will call you", indicating that he had not intended the clearance to be interpreted as a takeoff clearance. He probably had not heard the captain's announcement that they were "going," since Van Zanten had said this to his fellow crew members and not transmitted it on the radio himself.
A simultaneous radio call from the Pan Am crew caused mutual interference on the radio frequency, which was audible in the KLM cockpit as a whistling sound (or heterodyne). This made the crucial latter portion of the tower's response audible only with difficulty by the KLM crew. The Pan Am crew's transmission, which was also critical, was reporting that "We're still taxiing down the runway, the Clipper 1736!" This message was also blocked by the heterodyne and inaudible to the KLM crew. Either message, if heard in the KLM cockpit, would have given the KLM crew time to abort its second takeoff attempt.
Due to the fog, neither crew was able to see the other plane on the runway ahead of them. In addition, neither of the aircraft could be seen from the control tower, and the airport was not equipped with ground radar.
After the KLM plane had started its takeoff roll, the tower instructed the Pan Am crew to "report when runway clear." The crew replied: "OK, we'll report when we're clear." On hearing this, flight engineer Willem Schreuder expressed his concern about the Pan Am not being clear of the runway by asking the pilots, "Is he not clear, that Pan American?" Van Zanten emphatically replied "Oh, yes" and continued with the takeoff.[7]
Collision
Simplified map of runway, taxiways, and aircraft. The red star indicates the location of impact.According to the CVR, Captain Grubbs, captain of the Pan Am plane, spotted the KLM's landing lights just as the plane approached exit C-4, exclaiming, "Goddamn, that son-of-a-bitch is coming straight at us!" with the co-pilot Robert Bragg yelling, "Get off! Get off! Get off!". The Pan Am crew applied full power and took a sharp left turn towards the exit to avoid a collision. KLM Captain Van Zanten attempted to avoid a collision by climbing away, scraping the tail of the plane along the runway for 20 m (66 ft). As the KLM left the ground its steep angle of attack allowed the nose gear to clear the Pan Am but the lower fuselage and aft landing gears struck the upper right side of the Pan Am's fuselage at approximately 140 knots (260 km/h; 160 mph),[2] ripping apart the center of the Pan Am jet almost directly above the wing, and its right engines crashed through Pan Am's upper-deck passenger cabin, immediately behind the cockpit.
The KLM plane was briefly airborne, but the impact with the Pan Am had sheared off the #1 (outer left) engine, and the #2 (inner left) engine had ingested significant amounts of shredded materials from the Pan Am. The KLM pilot quickly lost control, and the 747 went into a stall, rolled sharply, slammed into the ground at a point 150 m (500 ft) past the collision and slid a further 300 m down the runway. As the jet was fully fuelled, a deadly fuel-air explosion ensued.
A survivor of the Pan Am flight, John Coombs of Haleiwa, Hawaii, said that sitting in the nose of the plane probably saved his life: "We all settled back, and the next thing an explosion took place and the whole port side, left side of the plane, was just torn wide open."[8]
Both airplanes were destroyed. All 234 passengers and 14 crew members in the KLM plane died, while 326 passengers and 9 crew members aboard the Pan Am flight were also killed,[9] primarily due to the fire and explosions resulting from the fuel spilled and ignited in the impact. The other 56 passengers and 5 crew members aboard the Pan Am aircraft survived, including the captain, first officer, and flight engineer. Most of the survivors on the Pan Am aircraft walked out onto the left wing, the side away from the collision, through holes in the fuselage structure. The Pan Am's engines were still running at takeoff power for a few minutes after the accident despite First Officer Bragg's intention to turn them off. The top part of the cockpit, where the engine switches were located, had been destroyed in the collision. After a short time running at full power the Pan-Am's engines began to disintegrate, throwing engine parts at high speed that killed a flight attendant who had escaped the burning plane. Survivors waited for rescue, but it did not come promptly as the firefighters were initially unaware that there were two aircraft involved and were concentrating on the KLM wreck some distance away in the thick fog. Eventually, most of the survivors on the wings dropped to the ground below.[2]
Captain Veldhuyzen van Zanten was KLM's chief of flight training and the airline's preferred pilot for publicity such as magazine advertisements. As such, KLM attempted to contact him to give public statements regarding the disaster, before learning that he was the captain involved.[10] Veldhuyzen van Zanten had given Klaas Meurs, the first officer on the ill-fated flight, his Boeing 747 qualification check about two months before the accident.[3]
InvestigationAbout 70 crash investigators from Spain, the Netherlands, the United States, and the two airline companies were involved in the investigation. Facts showed that there had been misinterpretations and false assumptions. Analysis of the CVR transcript showed that the KLM pilot was convinced that he had been cleared for takeoff, while the Tenerife control tower was certain that the KLM 747 was stationary at the end of the runway and awaiting takeoff clearance. It appears KLM's co-pilot was not as certain about take-off clearance as the captain.
Subsequent to the crash, first officer Robert Bragg, who was responsible for handling the Pan Am's radio communications, made public statements which conflict with statements made by the Pan Am crew in the official transcript of the CVR. In the documentary Crash of the Century (produced by the makers of Mayday), he stated he was convinced the tower controller had intended they take the fourth exit C-4 because the controller delivered the message to take "the third one, sir, one; two, three; third, third one" after the Pan Am's had already passed C-1 (making C-4 the third exit counting from there).[11] The CVR shows unequivocally that they received this message before they identified C-1, with the position of the aircraft somewhere between the entrance and C-1. Also, in a Time article, Bragg stated that he made the statement "What's he doing? He'll kill us all!" which does not appear in the CVR transcript.[12]
Probable causeThe investigation concluded that the fundamental cause of the accident was that Captain Van Zanten took off without takeoff clearance. The investigators suggested the reason for his mistake might have been a desire to leave as soon as possible in order to comply with KLM's duty-time regulations, and before the weather deteriorated further.
Other major factors contributing to the accident were:
The sudden fog greatly limited visibility. The control tower and the crews of both planes were unable to see one another.
Simultaneous radio transmissions, with the result that neither message could be heard.
The following factors were considered contributing but not critical:
Use of ambiguous non-standard phrases by the KLM co-pilot ("We're at take off") and the Tenerife control tower ("OK").
Pan Am mistakenly continued to exit C-4 instead of exiting at C-3 as directed.
The airport was (due to rerouting from the bomb threat) forced to accommodate a great number of large aircraft, resulting in disruption of the normal use of taxiways.[13]
[edit] Dutch responseThe Dutch authorities were reluctant to accept the Spanish report blaming the KLM captain for the accident. The Netherlands Department of Civil Aviation published a response that, whilst accepting that the KLM aircraft had taken off "prematurely", argued that he alone should not be blamed for the "mutual misunderstanding" that occurred between the controller and the KLM crew, and that limitations of using radio as a means of communication should have been given greater consideration.
In particular, the Dutch response pointed out that
the crowded airport had placed additional pressure on all parties, KLM, Pan Am, and the controller;
sounds on the CVR suggested that during the incident the Spanish control tower crew had been listening to a football game on the radio and may have been distracted.
the transmission from the tower in which the controller passed KLM their ATC clearance was ambiguous and could have been interpreted as also giving take-off clearance. In support of this part of their response, the Dutch investigators pointed out that Pan Am's messages "No! Eh?" and "We are still taxiing down the runway, the Clipper 1736!" indicated that Captain Grubbs and First Officer Bragg had recognised the ambiguity;
if the Pan Am aircraft had not taxied beyond the third exit, the collision would not have occurred.[14][15]
SpeculationsSpeculation regarding other contributing factors includes:
Captain Van Zanten's failure to confirm instructions from the tower. The flight was one of his first after spending six months training new pilots on a flight simulator, where he had been in charge of everything (including simulated ATC), and having been away from the real world of flying for extended periods.[2]
The flight engineer's apparent hesitation to challenge Van Zanten further, possibly because Captain Van Zanten was not only senior in rank, but also one of the most able and experienced pilots working for the airline.[2]
A study group put together by the Air Line Pilots Association found that not only the captain, but the first officer as well dismissed the flight engineer's question.[16] In that case, the flight engineer might have been either reassured or even less inclined to press the question further.
The reason only the flight engineer reacted to the radio transmission "Alpha one seven three six report when runway clear" might lie in the fact that this was the first and only time the Pan Am was referred to by that name. Before that, the plane was called "Clipper one seven three six". The flight engineer, having completed his pre-flight checks, might have recognized the numbers but his colleagues, preparing themselves for take-off, might have subconsciously been tuned in to "Clipper".
The extra fuel the KLM plane took on added several factors:
it delayed takeoff an extra 35 minutes, which gave time for the fog to settle in;
it added over forty tons of weight to the plane, which made it more difficult to clear the Pan Am when taking off;
it increased the size of the fire from the crash that ultimately killed everyone on board.
Captain Van Zanten's reaction, once he spotted the Pan Am plane, was to attempt to take off. Although the plane had exceeded its V1 speed,[17] it did not yet have adequate airspeed. The sharp lifting angle caused the KLM jet to drag its tail on the runway, thereby reducing its speed even further.
ResponsibilityAlthough the Dutch authorities were initially reluctant to blame Captain Van Zanten and his crew,[14][15] the airline ultimately accepted responsibility for the accident. KLM paid the victims or their families compensation ranging between $58,000 and $600,000.[18] As reported in a March 25, 1980, Washington Post article the sum of settlements for property and damages was $110 million (an average of $189,000 per victim[citation needed], due to limitations imposed by European Compensation Conventions in effect at the time).
[edit] Safety responseAs a consequence of the accident, sweeping changes were made to international airline regulations and to aircraft. Aviation authorities around the world introduced requirements for standard phrases and a greater emphasis on English as a common working language. For example, ICAO calls for the phrase "line up and wait" as an instruction to an aircraft moving into position but not cleared for takeoff. The FAA equivalent at the time was "position and hold" (though as of September 30, 2010, this has been changed to "line up and wait" to comply with ICAO standards.[19]). Also several national air safety boards began penalizing pilots for disobeying air traffic controller's orders. Air traffic instruction should not be acknowledged solely with a colloquial phrase such as "OK" or even "Roger", but with a readback of the key parts of the instruction, to show mutual understanding. Additionally, the phrase "takeoff" is only spoken when the actual takeoff clearance is given. Up until that point, both aircrew and controllers should use the phrase "departure" in its place (e.g. "ready for departure"). Cockpit procedures were also changed. Hierarchical relations among crew members were played down. More emphasis was placed on team decision-making by mutual agreement. This is known in the industry as Crew Resource Management.
In 1978 a second airport was inaugurated on the island: the new Tenerife South Airport (TFS). This airport now serves the majority of international tourist flights. Los Rodeos, renamed to Tenerife North Airport (TFN), was then used only for domestic and inter-island flights, but in 2002 a new terminal was opened and it carries international traffic once again, including budget airlines. The Spanish authorities installed a ground radar at Tenerife North following the accident.
The collision took place on March 27, 1977, at 17:06:56 local time. The aircraft were operating as Pan Am Flight 1736 (the Clipper Victor) under the command of Captain Victor Grubbs, and KLM Flight 4805 (the Rijn) under the command of Captain Jacob Veldhuyzen van Zanten. Taking off in heavy fog on the airport's only runway, the KLM flight crashed into the top of the Pan Am aircraft backtaxiing in the opposite direction. The Pan Am had followed the backtaxiing of the KLM aircraft, under the direction of air traffic control, and the KLM's flight crew had been aware of Pan Am backtaxiing behind them on the same runway. Despite lack of visual confirmation due to the fog the KLM captain thought that Pan Am had cleared the runway and so attempted to take off without further clearance to do so. Several other key factors contributed to the accident.
[edit] Flight historyFor both planes, Tenerife was an unscheduled stop. Their destination was Gran Canaria International Airport (also known as Las Palmas Airport), serving Las Palmas on the nearby island of Gran Canaria. Both are in the Canary Islands, an autonomous community of Spain located in the Atlantic Ocean off the west coast of Morocco.
Pan Am Flight 1736 had taken off from Los Angeles International Airport with an intermediate stop at New York's John F. Kennedy International Airport. The aircraft was a Boeing 747–121, registration N736PA. Of the 380 passengers, 14 had boarded in New York, where the crew was also changed. The new crew consisted of Captain Victor Grubbs, First Officer Robert Bragg, and Flight Engineer George Warns; there were 14 other crew members. The same aircraft had operated the inaugural 747 commercial flight on January 22, 1970.[1]
KLM Flight 4805, a charter flight for Holland International Travel Group from the Netherlands,[1] had taken off four hours before from Amsterdam Airport Schiphol. Its captain was Jacob Veldhuyzen van Zanten and the first officer was Klaas Meurs. The aircraft was a Boeing 747-206B, registration PH-BUF. The KLM jet had 14 crew members and 235 passengers, including 48 children and three infants. Most of the KLM passengers were Dutch; four Germans, two Austrians, and two Americans were also on the plane. After the aircraft landed at Tenerife, a Dutch tour guide named Robina van Lanschot, who lived on the island in Puerto de la Cruz and wanted to see her boyfriend that night, chose not to re-board the 747, leaving 234 passengers on board.[2][3]
Disaster[edit] Bombing at Las PalmasEvents on both planes had been routine until they approached the islands. Then, at 1:15 pm, a terrorist bomb (planted by separatist Fuerzas Armadas Guanches) exploded in the terminal of Gran Canaria International Airport.[4] It had been preceded by a phone call warning of the bomb. The civil aviation authorities closed that airport after the bomb detonated and diverted all of its incoming flights to Los Rodeos, including the two Boeing 747 aircraft involved in the disaster. Upon contacting Gran Canaria airport, the Pan Am flight was informed of the temporary closure. Although the Pan Am crew indicated that they would prefer to circle in a holding pattern until landing clearance was given, the plane was ordered to divert to Los Rodeos, along with the KLM flight. This led to the critical cramped aircraft conditions within the smaller airport.[5]
Congestion at Los RodeosIn all, at least five large aircraft were diverted to Los Rodeos, a regional airport that could not easily accommodate them. The airport consisted of one runway and one major taxiway parallel to it, as well as several small taxiways connecting the main taxiway and the runway. While waiting for Gran Canaria airport to reopen, the diverted aircraft took up so much space that they were parked on the long taxiway, meaning that it could not be used for taxiing. Instead, departing aircraft would have to taxi along the runway to position themselves for takeoff, a procedure known as a runway backtaxi.
RefuellingAfter the threat at Gran Canaria International Airport had been contained, authorities reopened the airport. The Pan Am aircraft was ready to depart, but the KLM plane and a refuelling vehicle obstructed the way to the active runway. The Pan Am aircraft was unable to maneuver around the fueling KLM, reach the runway and depart due to a lack of just 12 ft (3.7 m) of clearance.[2] Captain Van Zanten had decided to fully refuel at Los Rodeos instead of Las Palmas, apparently to save time, but by doing so he added extra weight, greatly retarding liftoff (and accident escape) ability, which proved fatal. The refuelling took about 35 minutes.
Taxiing and weather conditions This section needs additional citations for verification.
Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (January 2011)
Following the tower's instructions, the KLM aircraft was cleared to backtaxi the full length of runway 30 and make a 180° turn to put the aircraft in takeoff position — a difficult maneuver to perform with a 747 on a 45 m (150 ft) wide runway. While KLM 4805 was backtaxiing on runway 30, the controller asked the flight crew to report when it was ready to copy the ATC clearance. Because the flight crew was performing the checklist, copying this clearance was postponed until the aircraft was in takeoff position on Runway 30. During taxiing, the weather deteriorated and low-lying clouds now limited the visual range to about 300 m (1,000 ft). Legal or stipulated threshold for takeoff was 700 m (2,300 ft) visibility, as noted in the NOVA documentary and relayed by surviving Pan Am co-pilot Robert Bragg.
Shortly afterward, Pan Am 1736 was instructed to also backtaxi, to follow the KLM aircraft down the same runway, to exit the runway by taking the "third exit" on their left and then using the parallel taxiway. Initially the crew was unclear as to whether the controller had told them to take the first or third exit. The crew asked for clarification and the controller responded emphatically by replying: "The third one, sir; one, two, three; third, third one". The crew began the taxi and proceeded to identify the unmarked taxiways using an airport diagram as they reached them.
Based on the chronology of the cockpit voice recorder (CVR) and the distances between the taxiways (and the location of the aircraft at the time of the collision), the crew successfully identified the first two taxiways (C-1 and C-2), but their discussion in the cockpit never indicated that they had sighted the third taxiway (C-3), which they had been instructed to use. There were no markings or signs to identify the runway exits. The Pan Am crew appeared to remain unsure of their position on the runway until the collision, which occurred near the intersection with the fourth taxiway (C-4). Pan Am's lack of visibility and runway exiting confusion probably contributed to its slow taxiing speed, another key factor in the accident.
The angle of the third taxiway would have required the plane to perform a turn of approximately 145°, which would lead counter-productively back toward the still-crowded main apron. At the end of C-3 another 145° turn would have to be made to continue taxiing towards the start of the runway. Taxiway C-4 would have required just two 35° turns. A study carried out by the Air Line Pilots Association after the accident concluded that making the second 145° turn at the end of taxiway C-3 would have been "a practical impossibility", although the Dutch report stated that such a maneuver "could reasonably be performed". The official report from the Spanish authorities did not explain why the controller had instructed the Pan Am aircraft to use the third taxiway, rather than the sensible and easier fourth taxiway.[6]
Communication misunderstandingsImmediately after lining up, the KLM captain advanced the throttles (a standard procedure known as "spin-up", to verify that the engines are operating properly for takeoff) and co-pilot Meurs, surprised by the maneuver, quickly advised the captain that ATC clearance had not yet been given. Captain Van Zanten responded, "I know that. Go ahead, ask." Meurs then radioed the tower that they were "ready for takeoff" and "waiting for our ATC clearance". The KLM crew then received instructions which specified the route that the aircraft was to follow after takeoff. The instructions used the word "takeoff," but did not include an explicit statement that they were cleared for takeoff.
Meurs read the flight clearance back to the controller, completing the readback with the statement "we're now at takeoff" or "we're now, uh, taking off" (the exact wording of his statement was not clear[citation needed]), indicating to the controller that they were beginning their takeoff roll. Captain Van Zanten interrupted the co-pilot's readback with the comment "We're going". As noted in the NOVA documentary, Meurs chose not to embarrass his superior a second time by stating that they still did not have the proper clearance to take off.
The Spanish controller, who could not see the runway due to the fog, initially responded with "OK" (terminology which is nonstandard), which reinforced the KLM captain's misinterpretation that they had takeoff clearance. The controller's response of "OK" to the co-pilot's nonstandard statement that they were "now at takeoff" was likely due to his misinterpretation that they were in takeoff position and ready to begin the roll when takeoff clearance was received, but not actually in the process of taking off. The controller then immediately added "stand by for takeoff, I will call you", indicating that he had not intended the clearance to be interpreted as a takeoff clearance. He probably had not heard the captain's announcement that they were "going," since Van Zanten had said this to his fellow crew members and not transmitted it on the radio himself.
A simultaneous radio call from the Pan Am crew caused mutual interference on the radio frequency, which was audible in the KLM cockpit as a whistling sound (or heterodyne). This made the crucial latter portion of the tower's response audible only with difficulty by the KLM crew. The Pan Am crew's transmission, which was also critical, was reporting that "We're still taxiing down the runway, the Clipper 1736!" This message was also blocked by the heterodyne and inaudible to the KLM crew. Either message, if heard in the KLM cockpit, would have given the KLM crew time to abort its second takeoff attempt.
Due to the fog, neither crew was able to see the other plane on the runway ahead of them. In addition, neither of the aircraft could be seen from the control tower, and the airport was not equipped with ground radar.
After the KLM plane had started its takeoff roll, the tower instructed the Pan Am crew to "report when runway clear." The crew replied: "OK, we'll report when we're clear." On hearing this, flight engineer Willem Schreuder expressed his concern about the Pan Am not being clear of the runway by asking the pilots, "Is he not clear, that Pan American?" Van Zanten emphatically replied "Oh, yes" and continued with the takeoff.[7]
Collision
Simplified map of runway, taxiways, and aircraft. The red star indicates the location of impact.According to the CVR, Captain Grubbs, captain of the Pan Am plane, spotted the KLM's landing lights just as the plane approached exit C-4, exclaiming, "Goddamn, that son-of-a-bitch is coming straight at us!" with the co-pilot Robert Bragg yelling, "Get off! Get off! Get off!". The Pan Am crew applied full power and took a sharp left turn towards the exit to avoid a collision. KLM Captain Van Zanten attempted to avoid a collision by climbing away, scraping the tail of the plane along the runway for 20 m (66 ft). As the KLM left the ground its steep angle of attack allowed the nose gear to clear the Pan Am but the lower fuselage and aft landing gears struck the upper right side of the Pan Am's fuselage at approximately 140 knots (260 km/h; 160 mph),[2] ripping apart the center of the Pan Am jet almost directly above the wing, and its right engines crashed through Pan Am's upper-deck passenger cabin, immediately behind the cockpit.
The KLM plane was briefly airborne, but the impact with the Pan Am had sheared off the #1 (outer left) engine, and the #2 (inner left) engine had ingested significant amounts of shredded materials from the Pan Am. The KLM pilot quickly lost control, and the 747 went into a stall, rolled sharply, slammed into the ground at a point 150 m (500 ft) past the collision and slid a further 300 m down the runway. As the jet was fully fuelled, a deadly fuel-air explosion ensued.
A survivor of the Pan Am flight, John Coombs of Haleiwa, Hawaii, said that sitting in the nose of the plane probably saved his life: "We all settled back, and the next thing an explosion took place and the whole port side, left side of the plane, was just torn wide open."[8]
Both airplanes were destroyed. All 234 passengers and 14 crew members in the KLM plane died, while 326 passengers and 9 crew members aboard the Pan Am flight were also killed,[9] primarily due to the fire and explosions resulting from the fuel spilled and ignited in the impact. The other 56 passengers and 5 crew members aboard the Pan Am aircraft survived, including the captain, first officer, and flight engineer. Most of the survivors on the Pan Am aircraft walked out onto the left wing, the side away from the collision, through holes in the fuselage structure. The Pan Am's engines were still running at takeoff power for a few minutes after the accident despite First Officer Bragg's intention to turn them off. The top part of the cockpit, where the engine switches were located, had been destroyed in the collision. After a short time running at full power the Pan-Am's engines began to disintegrate, throwing engine parts at high speed that killed a flight attendant who had escaped the burning plane. Survivors waited for rescue, but it did not come promptly as the firefighters were initially unaware that there were two aircraft involved and were concentrating on the KLM wreck some distance away in the thick fog. Eventually, most of the survivors on the wings dropped to the ground below.[2]
Captain Veldhuyzen van Zanten was KLM's chief of flight training and the airline's preferred pilot for publicity such as magazine advertisements. As such, KLM attempted to contact him to give public statements regarding the disaster, before learning that he was the captain involved.[10] Veldhuyzen van Zanten had given Klaas Meurs, the first officer on the ill-fated flight, his Boeing 747 qualification check about two months before the accident.[3]
InvestigationAbout 70 crash investigators from Spain, the Netherlands, the United States, and the two airline companies were involved in the investigation. Facts showed that there had been misinterpretations and false assumptions. Analysis of the CVR transcript showed that the KLM pilot was convinced that he had been cleared for takeoff, while the Tenerife control tower was certain that the KLM 747 was stationary at the end of the runway and awaiting takeoff clearance. It appears KLM's co-pilot was not as certain about take-off clearance as the captain.
Subsequent to the crash, first officer Robert Bragg, who was responsible for handling the Pan Am's radio communications, made public statements which conflict with statements made by the Pan Am crew in the official transcript of the CVR. In the documentary Crash of the Century (produced by the makers of Mayday), he stated he was convinced the tower controller had intended they take the fourth exit C-4 because the controller delivered the message to take "the third one, sir, one; two, three; third, third one" after the Pan Am's had already passed C-1 (making C-4 the third exit counting from there).[11] The CVR shows unequivocally that they received this message before they identified C-1, with the position of the aircraft somewhere between the entrance and C-1. Also, in a Time article, Bragg stated that he made the statement "What's he doing? He'll kill us all!" which does not appear in the CVR transcript.[12]
Probable causeThe investigation concluded that the fundamental cause of the accident was that Captain Van Zanten took off without takeoff clearance. The investigators suggested the reason for his mistake might have been a desire to leave as soon as possible in order to comply with KLM's duty-time regulations, and before the weather deteriorated further.
Other major factors contributing to the accident were:
The sudden fog greatly limited visibility. The control tower and the crews of both planes were unable to see one another.
Simultaneous radio transmissions, with the result that neither message could be heard.
The following factors were considered contributing but not critical:
Use of ambiguous non-standard phrases by the KLM co-pilot ("We're at take off") and the Tenerife control tower ("OK").
Pan Am mistakenly continued to exit C-4 instead of exiting at C-3 as directed.
The airport was (due to rerouting from the bomb threat) forced to accommodate a great number of large aircraft, resulting in disruption of the normal use of taxiways.[13]
[edit] Dutch responseThe Dutch authorities were reluctant to accept the Spanish report blaming the KLM captain for the accident. The Netherlands Department of Civil Aviation published a response that, whilst accepting that the KLM aircraft had taken off "prematurely", argued that he alone should not be blamed for the "mutual misunderstanding" that occurred between the controller and the KLM crew, and that limitations of using radio as a means of communication should have been given greater consideration.
In particular, the Dutch response pointed out that
the crowded airport had placed additional pressure on all parties, KLM, Pan Am, and the controller;
sounds on the CVR suggested that during the incident the Spanish control tower crew had been listening to a football game on the radio and may have been distracted.
the transmission from the tower in which the controller passed KLM their ATC clearance was ambiguous and could have been interpreted as also giving take-off clearance. In support of this part of their response, the Dutch investigators pointed out that Pan Am's messages "No! Eh?" and "We are still taxiing down the runway, the Clipper 1736!" indicated that Captain Grubbs and First Officer Bragg had recognised the ambiguity;
if the Pan Am aircraft had not taxied beyond the third exit, the collision would not have occurred.[14][15]
SpeculationsSpeculation regarding other contributing factors includes:
Captain Van Zanten's failure to confirm instructions from the tower. The flight was one of his first after spending six months training new pilots on a flight simulator, where he had been in charge of everything (including simulated ATC), and having been away from the real world of flying for extended periods.[2]
The flight engineer's apparent hesitation to challenge Van Zanten further, possibly because Captain Van Zanten was not only senior in rank, but also one of the most able and experienced pilots working for the airline.[2]
A study group put together by the Air Line Pilots Association found that not only the captain, but the first officer as well dismissed the flight engineer's question.[16] In that case, the flight engineer might have been either reassured or even less inclined to press the question further.
The reason only the flight engineer reacted to the radio transmission "Alpha one seven three six report when runway clear" might lie in the fact that this was the first and only time the Pan Am was referred to by that name. Before that, the plane was called "Clipper one seven three six". The flight engineer, having completed his pre-flight checks, might have recognized the numbers but his colleagues, preparing themselves for take-off, might have subconsciously been tuned in to "Clipper".
The extra fuel the KLM plane took on added several factors:
it delayed takeoff an extra 35 minutes, which gave time for the fog to settle in;
it added over forty tons of weight to the plane, which made it more difficult to clear the Pan Am when taking off;
it increased the size of the fire from the crash that ultimately killed everyone on board.
Captain Van Zanten's reaction, once he spotted the Pan Am plane, was to attempt to take off. Although the plane had exceeded its V1 speed,[17] it did not yet have adequate airspeed. The sharp lifting angle caused the KLM jet to drag its tail on the runway, thereby reducing its speed even further.
ResponsibilityAlthough the Dutch authorities were initially reluctant to blame Captain Van Zanten and his crew,[14][15] the airline ultimately accepted responsibility for the accident. KLM paid the victims or their families compensation ranging between $58,000 and $600,000.[18] As reported in a March 25, 1980, Washington Post article the sum of settlements for property and damages was $110 million (an average of $189,000 per victim[citation needed], due to limitations imposed by European Compensation Conventions in effect at the time).
[edit] Safety responseAs a consequence of the accident, sweeping changes were made to international airline regulations and to aircraft. Aviation authorities around the world introduced requirements for standard phrases and a greater emphasis on English as a common working language. For example, ICAO calls for the phrase "line up and wait" as an instruction to an aircraft moving into position but not cleared for takeoff. The FAA equivalent at the time was "position and hold" (though as of September 30, 2010, this has been changed to "line up and wait" to comply with ICAO standards.[19]). Also several national air safety boards began penalizing pilots for disobeying air traffic controller's orders. Air traffic instruction should not be acknowledged solely with a colloquial phrase such as "OK" or even "Roger", but with a readback of the key parts of the instruction, to show mutual understanding. Additionally, the phrase "takeoff" is only spoken when the actual takeoff clearance is given. Up until that point, both aircrew and controllers should use the phrase "departure" in its place (e.g. "ready for departure"). Cockpit procedures were also changed. Hierarchical relations among crew members were played down. More emphasis was placed on team decision-making by mutual agreement. This is known in the industry as Crew Resource Management.
In 1978 a second airport was inaugurated on the island: the new Tenerife South Airport (TFS). This airport now serves the majority of international tourist flights. Los Rodeos, renamed to Tenerife North Airport (TFN), was then used only for domestic and inter-island flights, but in 2002 a new terminal was opened and it carries international traffic once again, including budget airlines. The Spanish authorities installed a ground radar at Tenerife North following the accident.
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