Tenerife airport disaster: Difference between revisions

Coordinates: 28°28′54″N 16°20′18″W / 28.48165°N 16.3384°W / 28.48165; -16.3384
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→‎Communication misunderstandings: Added citation, under the section "Accident-initiating factors" in the citation, it said, "The controller had no intention of giving KLM a takeoff clearance."
"the Pan Am crew" is a group of people, so they.
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=== Diversion of aircraft to Los Rodeos ===
=== Diversion of aircraft to Los Rodeos ===
Both flights had been routine until they approached the islands. At 1:15 pm, a bomb (planted by the [[separatist]] [[Francisco Franco|anti-Francoist]] [[Fuerzas Armadas Guanches]]) exploded in the terminal of Gran Canaria International Airport, injuring one person.<ref>[http://www.1001crash.com/index-page-tenerife-lg-2.html The Tenerife disaster]. 1001 Crash (1977-03-27). Retrieved on 2011-01-14.</ref> There had been a phone call warning of the bomb, and soon after another call claimed that a second bomb was at the airport. The civil aviation authorities had therefore closed the airport temporarily after the bomb detonated and diverted all of its incoming flights to Los Rodeos, including the two Boeing 747 aircraft involved in the disaster.<ref name=ASN>{{cite web|title=ASN Accident Description|url=http://aviation-safety.net/database/record.php?id=19770327-0|publisher=Aviation Safety Network|accessdate=11 May 2011}}</ref> The Pan Am crew indicated that it would prefer to circle in a holding pattern until landing clearance was given, but was ordered to divert to Los Rodeos.<ref>[http://www.tenerife-information-centre.com/tenerife-airport-disaster.html The Tenerife Airport Disaster – the worst in aviation history]. Tenerife-information-centre.com (1977-03-27). Retrieved on 2011-01-14.</ref>
Both flights had been routine until they approached the islands. At 1:15 pm, a bomb (planted by the [[separatist]] [[Francisco Franco|anti-Francoist]] [[Fuerzas Armadas Guanches]]) exploded in the terminal of Gran Canaria International Airport, injuring one person.<ref>[http://www.1001crash.com/index-page-tenerife-lg-2.html The Tenerife disaster]. 1001 Crash (1977-03-27). Retrieved on 2011-01-14.</ref> There had been a phone call warning of the bomb, and soon after another call claimed that a second bomb was at the airport. The civil aviation authorities had therefore closed the airport temporarily after the bomb detonated and diverted all of its incoming flights to Los Rodeos, including the two Boeing 747 aircraft involved in the disaster.<ref name=ASN>{{cite web|title=ASN Accident Description|url=http://aviation-safety.net/database/record.php?id=19770327-0|publisher=Aviation Safety Network|accessdate=11 May 2011}}</ref> The Pan Am crew indicated that they would prefer to circle in a holding pattern until landing clearance was given, but were ordered to divert to Los Rodeos.<ref>[http://www.tenerife-information-centre.com/tenerife-airport-disaster.html The Tenerife Airport Disaster – the worst in aviation history]. Tenerife-information-centre.com (1977-03-27). Retrieved on 2011-01-14.</ref>


In all, at least five large aircraft were diverted to Los Rodeos, a regional airport that could not easily accommodate them. The airport had only 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]] or backtrack.<ref name=ASN/>
In all, at least five large aircraft were diverted to Los Rodeos, a regional airport that could not easily accommodate them. The airport had only 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]] or backtrack.<ref name=ASN/>
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Tenerife / Los Rodeos airport is at {{convert|633|m|abbr=off}} [[Height above mean sea level|above sea level]], which accounts for cloud behaviour that differs from that at most other airports. Clouds at {{convert|600|m|abbr=on}} above ground level at the nearby coast, are at ground level at Los Rodeos / Tenerife North. Drifting clouds from different densities cause wildly varying visibilities, from unhindered at one moment to below the minimums the next. The collision took place in a high density cloud.<ref>{{PDF|[http://www.project-tenerife.com/engels/PDF/alpa.pdf ALPA report on the crash]|2.70&nbsp;MB}}, p. 8 (PDF page 12 of 97)</ref>
Tenerife / Los Rodeos airport is at {{convert|633|m|abbr=off}} [[Height above mean sea level|above sea level]], which accounts for cloud behaviour that differs from that at most other airports. Clouds at {{convert|600|m|abbr=on}} above ground level at the nearby coast, are at ground level at Los Rodeos / Tenerife North. Drifting clouds from different densities cause wildly varying visibilities, from unhindered at one moment to below the minimums the next. The collision took place in a high density cloud.<ref>{{PDF|[http://www.project-tenerife.com/engels/PDF/alpa.pdf ALPA report on the crash]|2.70&nbsp;MB}}, p. 8 (PDF page 12 of 97)</ref>


The Pan Am crew found itself in poor and rapidly deteriorating visibility almost as soon as they entered the runway. According to the ALPA report, as the Pan Am aircraft taxied to the runway, the visibility was about {{convert|500|m|abbr=on}}. Shortly after they turned onto the runway it decreased to less than {{convert|100|m|abbr=on}}.<ref>{{PDF|[http://www.project-tenerife.com/engels/PDF/alpa.pdf ALPA report on the crash]|2.70&nbsp;MB}}, p. 11 (PDF page 15 of 97)</ref>
The Pan Am crew found themselves in poor and rapidly deteriorating visibility almost as soon as they entered the runway. According to the ALPA report, as the Pan Am aircraft taxied to the runway, the visibility was about {{convert|500|m|abbr=on}}. Shortly after they turned onto the runway it decreased to less than {{convert|100|m|abbr=on}}.<ref>{{PDF|[http://www.project-tenerife.com/engels/PDF/alpa.pdf ALPA report on the crash]|2.70&nbsp;MB}}, p. 11 (PDF page 15 of 97)</ref>


Meanwhile, the KLM aircraft was still in good visibility, but with clouds blowing down the runway towards them. "The KLM aircraft completed its 180 degree turn in relatively clear weather and lined up on Runway 30. The next cloud was some {{convert|900|m|abbr=on}} down the runway and moving towards the aircraft at about 12 knots (6 meters per second)".<ref>{{PDF|[http://www.project-tenerife.com/engels/PDF/alpa.pdf ALPA report on the crash]|2.70&nbsp;MB}}, p. 12 (PDF page 16 of 97)</ref>
Meanwhile, the KLM aircraft was still in good visibility, but with clouds blowing down the runway towards them. "The KLM aircraft completed its 180 degree turn in relatively clear weather and lined up on Runway 30. The next cloud was some {{convert|900|m|abbr=on}} down the runway and moving towards the aircraft at about 12 knots (6 meters per second)".<ref>{{PDF|[http://www.project-tenerife.com/engels/PDF/alpa.pdf ALPA report on the crash]|2.70&nbsp;MB}}, p. 12 (PDF page 16 of 97)</ref>

Revision as of 00:29, 25 February 2014

Tenerife airport disaster
KLM Flight 4805 · Pan Am Flight 1736
Accident
DateMarch 27, 1977
SummaryPilot error, runway incursion, poor weather conditions, limitations and failures in communication
Site
Los Rodeos Airport
(now Tenerife North Airport)
Tenerife, Canary Islands, Spain
Total fatalities583
Total injuries61
Total survivors61
First aircraft

A Pan Am Boeing 747-121
similar to the one involved.
TypeBoeing 747–121
NameClipper Victor
OperatorPan American World Airways
RegistrationN736PAdisaster[1]
Flight originLos Angeles Int'l Airport
Los Angeles, United States
StopoverJohn F. Kennedy Int'l Airport
New York City, United States
DestinationGran Canaria Airport
Canary Islands, Spain
Passengers380
Crew16
Fatalities335 (326 passengers, 9 crew)
Injuries61
Survivors61
Second aircraft

PH-BUF, the KLM Boeing 747-206B involved in the incident.
TypeBoeing 747-206B
NameRijn  ("Rhine")
OperatorKLM Royal Dutch Airlines
RegistrationPH-BUFdisaster[2]
Flight originSchiphol Airport
Amsterdam, Netherlands
DestinationGran Canaria Airport
Canary Islands, Spain
Passengers234
Crew14
Fatalities248 (all)
Survivors0

The Tenerife airport disaster was a fatal collision between two Boeing 747 passenger aircraft which occurred on Sunday, March 27, 1977, 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 a total of 583 fatalities, the crash is the deadliest accident in aviation history.

After a bomb exploded at Gran Canaria Airport, many aircraft were diverted to Tenerife. Among them were KLM Flight 4805 and Pan Am Flight 1736 – the two aircraft involved in the accident. The threat of a second bomb forced the authorities to close the airport while a search was conducted, resulting in many airplanes being diverted to the smaller Tenerife airport where air traffic controllers were forced to park many of the airplanes on the taxiway, thereby blocking it. Further complicating the situation, while authorities waited to reopen Gran Canaria, a dense fog developed at Tenerife, greatly reducing visibility.

When Gran Canaria reopened, the parked aircraft blocking the taxiway at Tenerife required both of the 747s to taxi on the only runway in order to get in position for takeoff. The fog was so thick that neither aircraft could see the other, nor could the controller in the tower see the runway or the two 747s on it. As the airport did not have ground radar, the only means for the controller to identify the location of each airplane was via voice reports over the radio. As a result of several misunderstandings in the ensuing communication, the KLM flight attempted to take off while the Pan Am flight was still on the runway. The resulting collision destroyed both aircraft, killing all 248 aboard the KLM flight and 335 of 396 aboard the Pan Am flight. Sixty-one people aboard the Pan Am flight, including the pilots and flight engineer, survived the disaster.[3]

As the accident occurred in Spanish territory, that nation was responsible for investigating the accident. Investigators from the Netherlands and the United States also participated. The investigation revealed that the primary cause of the accident was the captain of the KLM flight taking off without clearance from Air Traffic Control (ATC).[3] The investigation specified that the captain did not intentionally take off without clearance; rather he fully believed he had clearance to take off due to misunderstandings between his flight crew and ATC.[3] Dutch investigators placed a greater emphasis on this than their American and Spanish counterparts,[4] but ultimately KLM admitted their crew was responsible for the accident, and the airline financially compensated the victims' relatives.[5]

The accident had a lasting influence on the industry, particularly in the area of communication. An increased emphasis was placed on using standardized phraseology in ATC communication by both controllers and pilots alike, thereby reducing the chance for misunderstandings. As part of these changes, the word "takeoff" was removed from general usage, and is only spoken by ATC when actually clearing an aircraft to take off.[6] Less experienced flight crew members were encouraged to challenge their captains when they believed something was not correct, and captains were instructed to listen to their crew and evaluate all decisions in light of crew concerns. This concept was later expanded into what is known today as Crew Resource Management. CRM training is now mandatory for all airline pilots.[7]

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 southwest coast of Morocco.

Pan Am Flight 1736 had originated at 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, named "Clipper Victor". Of the 380 passengers (mostly in retirement age, but also including two children), 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 13 other crew members. The same aircraft had operated the inaugural 747 commercial flight on January 22, 1970.[8]

KLM Flight 4805, a charter flight for Holland International Travel Group, had arrived from Amsterdam Airport Schiphol, the Netherlands.[8] Its captain was Jacob Veldhuyzen van Zanten, KLM's chief flying instructor.[9] The First Officer was Klaas Meurs and the Flight Engineer was Willem Schreuder. The aircraft was a Boeing 747-206B, registration PH-BUF, named "Rijn (Rhine)". The KLM jet had 14 crew members and 235 passengers, including 52 children. 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, the passengers were transported to the airport terminal. When it was time to leave, a Dutch tour guide named Robina van Lanschot, who lived on the island in the town of Puerto de la Cruz and wanted to see her boyfriend there that night, chose not to re-board the 747, leaving 234 passengers on board.[10][11]

Disaster

Diversion of aircraft to Los Rodeos

Both flights had been routine until they approached the islands. At 1:15 pm, a bomb (planted by the separatist anti-Francoist Fuerzas Armadas Guanches) exploded in the terminal of Gran Canaria International Airport, injuring one person.[12] There had been a phone call warning of the bomb, and soon after another call claimed that a second bomb was at the airport. The civil aviation authorities had therefore closed the airport temporarily after the bomb detonated and diverted all of its incoming flights to Los Rodeos, including the two Boeing 747 aircraft involved in the disaster.[3] The Pan Am crew indicated that they would prefer to circle in a holding pattern until landing clearance was given, but were ordered to divert to Los Rodeos.[13]

In all, at least five large aircraft were diverted to Los Rodeos, a regional airport that could not easily accommodate them. The airport had only 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 or backtrack.[3]

After the threat at Gran Canaria International Airport had been contained, authorities reopened that airport. The Pan Am aircraft was ready to depart from Tenerife, but the KLM plane and a refueling vehicle obstructed its access to the 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.[10] Captain Veldhuyzen van Zanten had decided to fully refuel at Los Rodeos instead of Las Palmas, apparently to save time. The refueling took about 35 minutes. After that, the passengers were brought back to the plane. The search for a missing family of four delayed the flight even further.

Taxiing and takeoff preparations

Following the tower's instructions, the KLM aircraft was cleared to backtaxi the full length of runway 30 and make a 180° turn to place the aircraft in takeoff position.[14] 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.[15]

Shortly afterward, Pan Am 1736 was also instructed to backtaxi, to follow the KLM aircraft down the same runway, to exit the runway by taking the third exit on their left and then use 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.[16]

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.[17] There were no markings or signs to identify the runway exits and they were in conditions of poor visibility. 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).[18]

The angle of the third taxiway would have required the plane to perform a turn of approximately 148°, which would lead back toward the still-crowded main apron. At the end of C-3, another 148° turn would have to be made, in order to continue taxiing towards the start of the runway. Taxiway C-4 would have required two turns of just 35°. A study carried out by the Air Line Pilots Association after the accident concluded that making the second 148° turn at the end of taxiway C-3 would have been "a practical impossibility".[19] Subsequent performance calculations and taxi tests with a B747 turning off on an intersection comparable to the C-3 at Tenerife, as part of the Dutch investigation, indicate that in all probability the turns could have been made. The official report from the Spanish authorities explains that the controller instructed the Pan Am aircraft to use the third taxiway because this was the earliest exit that they could take to reach the unobstructed section of the parallel taxiway.[20]

Weather conditions at Los Rodeos

Tenerife / Los Rodeos airport is at 633 metres (2,077 feet) above sea level, which accounts for cloud behaviour that differs from that at most other airports. Clouds at 600 m (2,000 ft) above ground level at the nearby coast, are at ground level at Los Rodeos / Tenerife North. Drifting clouds from different densities cause wildly varying visibilities, from unhindered at one moment to below the minimums the next. The collision took place in a high density cloud.[21]

The Pan Am crew found themselves in poor and rapidly deteriorating visibility almost as soon as they entered the runway. According to the ALPA report, as the Pan Am aircraft taxied to the runway, the visibility was about 500 m (1,600 ft). Shortly after they turned onto the runway it decreased to less than 100 m (330 ft).[22]

Meanwhile, the KLM aircraft was still in good visibility, but with clouds blowing down the runway towards them. "The KLM aircraft completed its 180 degree turn in relatively clear weather and lined up on Runway 30. The next cloud was some 900 m (3,000 ft) down the runway and moving towards the aircraft at about 12 knots (6 meters per second)".[23]

Communication misunderstandings

Immediately after lining up, the KLM captain advanced the throttles and the aircraft started to move forward.[29] The co-pilot advised the captain that ATC clearance had not yet been given, and Captain Veldhuyzen 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 are now at takeoff."[3] Captain Veldhuyzen van Zanten interrupted the co-pilot's read-back with the comment, "We're going."[3]

The 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 in the process of taking off. The controller then immediately added "stand by for takeoff, I will call you,"[3] indicating that he had not intended the clearance to be interpreted as a takeoff clearance.[30]

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 three second long whistling sound (or heterodyne). This caused the KLM crew to miss the crucial latter portion of the tower's response. The Pan Am crew's transmission was "We're still taxiing down the runway, the Clipper 1736!". This message was also blocked by the interference and inaudible to the KLM crew. Either message, if heard in the KLM cockpit, would have alerted the crew to the situation and given them time to abort the takeoff attempt.[31]

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.[3]

After the KLM plane had started its takeoff roll, the tower instructed the Pan Am crew to "report when runway clear." The Pan Am crew replied: "OK, we'll report when we're clear." On hearing this, the KLM flight engineer expressed his concern about the Pan Am not being clear of the runway by asking the pilots in his own cockpit, "Is he not clear, that Pan American?" Veldhuyzen van Zanten emphatically replied "Oh, yes" and continued with the takeoff.[32]

Collision

Simplified map of runway, taxiways, and aircraft. The red star indicates the location of impact. Not to scale.

According to the CVR, Captain Grubbs, captain of the Pan Am plane, said, "There he is." when he spotted the KLM's landing lights through the fog just as his plane approached exit C-4. When it became clear that the KLM was approaching at takeoff speed, Grubbs exclaimed, "Goddamn, that son-of-a-bitch is coming straight at us!" while the co-pilot Robert Bragg yelled, "Get off! Get off! Get off!". The Pan Am crew applied full power to the throttles and took a sharp left turn towards the grass in an attempt to avoid a collision.[3] By the time Captain Veldhuyzen van Zanten noticed the Pan Am on the runway ahead, his aircraft was already traveling too fast to stop. In desperation he prematurely rotated his aircraft and attempted to clear the Pan Am by climbing away, causing a tailstrike for 20 m (66 ft).

The KLM was within 100 m (330 ft) of the Pan Am when it left the ground. As it did so, its nose gear cleared the Pan Am but the engines, 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),[10] ripping apart the center of the Pan Am jet almost directly above the wing. The right side engines crashed through the Pan Am's upper deck immediately behind the cockpit.

The KLM plane remained briefly airborne following the collision, but the impact with the Pan Am had sheared off the #1 (outer left) engine, caused significant amounts of shredded materials to be ingested by the #2 (inner left) engine, and damaged the wings. The crew quickly lost control and the 747 went into a stall, rolled sharply, and hit the ground at a point approximately 150 m (500 ft) past the collision, sliding a further 300 m (1,000 ft) down the runway. The full load of fuel, which had caused the earlier delay, ignited immediately.

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."[33]

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 killed,[34] 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 pilots 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, and all control lines were severed, leaving no method for the flight crew to control the aircraft's systems. 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.[10]

Captain Veldhuyzen van Zanten was KLM's chief of flight training. His photograph was used for publicity materials such as magazine advertisements, including the inflight magazine on board PH-BUF.[10][35] As such, KLM suggested that he should be part of the investigation team, before learning that he was the captain involved.[36] He had given the co-pilot on the flight his Boeing 747 qualification check about two months before the accident.[11]

Investigation

About 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 a public statement which conflicts 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 had already passed C-1 (making C-4 the third exit counting from there).[37]

Probable cause

The investigation concluded that the fundamental cause of the accident was that Captain Veldhuyzen 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.
  • Interference from 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").
  • The Pan Am aircraft had not exited the runway at C-3.
  • 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.[38]

Dutch response

The 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 match 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 (this message was not audible to the control tower or KLM crew due to simultaneous cross-communication);
  • The Pan Am had taxied beyond the third exit. Had the plane turned at the third exit as instructed, the collision would not have occurred.[4][39]

Although the Dutch authorities were initially reluctant to blame Captain Veldhuyzen van Zanten and his crew,[4][39] the airline ultimately accepted responsibility for the accident. KLM paid the victims or their families compensation ranging between $58,000 and $600,000.[5] The sum of settlements for property and damages was $110 million[40] (an average of $189,000 per victim,[citation needed] due to limitations imposed by European Compensation Conventions in effect at the time).

Speculations

This was one of the first accident investigations during which the contribution of "human factors" was studied.[41] The human factors included:

  • The flight was one of Captain Veldhuyzen van Zanten's first after spending six months training new pilots on a flight simulator,[citation needed] where he had been in charge of everything (including simulated ATC), hence having been away from the real world of flying for an extended period.[10]
  • The flight engineer's and the first officer's apparent hesitation to challenge Veldhuyzen van Zanten further. The official investigation suggested that this might have been because the captain was not only senior in rank, but also one of the most respected pilots working for the airline.[10][42] This view is questioned by Jan Bartelski, a former KLM Captain and the president of the International Federation of Air Line Pilots' Associations (IFALPA), who knew both men and believes that this explanation is inconsistent with his experience of their personalities.[43]
  • The reason only the flight engineer on the KLM plane reacted to the radio transmission "OK, we'll report when we're clear" might lie in the fact that by then he had completed his pre-flight checks, whereas his colleagues were experiencing an increased workload, just at the same time as the visibility worsened.[44]
  • The ALPA study group concluded that the KLM crew did not realise that the transmission "Papa Alpha one seven three six report when runway clear" was directed at the other 747 because 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".[45]

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[46] to the plane, which increased the takeoff distance and 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.[47][48][49]

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. Also several national air safety boards began penalizing pilots for disobeying air traffic controllers' orders. Air traffic instruction should not be acknowledged solely with a colloquial phrase such as "OK" or even "Roger" (which simply means the last transmission was received[50]), but with a readback of the key parts of the instruction, to show mutual understanding. Additionally, the phrase "takeoff" is spoken only 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, part of what has become known in the industry as Crew Resource Management.[51]

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.

Memorials

Monument in Westgaarde Cemetery, Amsterdam
File:Monumento Conmemmorativo Internacional 27 de Marzo de 1977.jpg
International Tenerife Memorial March 27, 1977, Mount Mesa Mota, Tenerife, Canary Islands, Spain

A Dutch national memorial and final resting place for the victims of the KLM plane is located in Amsterdam, at Westgaarde cemetery. There is also a memorial at the Westminster Memorial Park and Mortuary in Westminster, California.

The 30th anniversary marked the first time that Dutch and American next of kin, and aid helpers from Tenerife, joined in international commemoration service held at the Auditorio de Tenerife in Santa Cruz; the International Tenerife Memorial March 27, 1977 was inaugurated at the Mesa Mota March 27, 2007. The monument was designed by Dutch sculptor Rudi van de Wint.

Notable victims

Documentaries

The disaster has been featured in many TV shows and documentaries. These include the Mayday special episode "Crash of the Century", the Survival in the Sky episode "Blaming the Pilot", the Seconds From Disaster episode "Collision on the Runway", PBS's NOVA episode "The Deadliest Plane Crash" in 2006, the PBS special "Surviving Disaster: How the Brain Works Under Extreme Duress" (based on Amanda Ripley's book "The Unthinkable") in 2011, and the Discovery Channel TV series Most Deadly and Destroyed in Seconds.

See also

References

  1. ^ "FAA Registry (N736PA)". Federal Aviation Administration.
  2. ^ "Civil aircraft register (PH-BUF)". Inspectie Leefomgeving en Transport.
  3. ^ a b c d e f g h i j "ASN Accident Description". Aviation Safety Network. Retrieved 11 May 2011.
  4. ^ a b c "Dutch comments on the Spanish report" (PDF). Project-Tenerife.
  5. ^ a b "How KLM accepted their responsibility for the accident". Project-Tenerife.
  6. ^ "The Tenerife Airport Disaster - the worst in aviation history". Tenerife Information Centre. Retrieved 11 May 2011.
  7. ^ Baron, Robert. "The Cockpit, the Cabin, and Social Psychology". Global Operators Flight Information Resource. Retrieved 11 May 2011.
  8. ^ a b Kilroy, Chris Special Report: Tenerife AirDisaster.com.
  9. ^ Template:PDF, section 5.2, p. 38 (PDF page 41 of 63)"
  10. ^ a b c d e f g Macarthur Job (1995). Air Disaster Volume 1, ISBN 1-875671-11-0, pp.164–180
  11. ^ a b "The Deadliest Plane Crash". PBS. October 17, 2006. Retrieved 2007-07-26.
  12. ^ The Tenerife disaster. 1001 Crash (1977-03-27). Retrieved on 2011-01-14.
  13. ^ The Tenerife Airport Disaster – the worst in aviation history. Tenerife-information-centre.com (1977-03-27). Retrieved on 2011-01-14.
  14. ^ Template:PDF, p. 2 (PDF page 5 of 63)
  15. ^ Template:PDF, p. 3-4 (PDF pages 6-7 of 63)
  16. ^ Template:PDF, p. 3 (PDF page 6 of 63)
  17. ^ Template:PDF, pp. 56-57 (PDF pages 59-60 of 63)
  18. ^ Template:PDF
  19. ^ Template:PDF, p. 19 (PDF page 23 of 97)
  20. ^ Template:PDF, pp. 46 (PDF page 49 of 63)
  21. ^ Template:PDF, p. 8 (PDF page 12 of 97)
  22. ^ Template:PDF, p. 11 (PDF page 15 of 97)
  23. ^ Template:PDF, p. 12 (PDF page 16 of 97)
  24. ^ "Project-Tenerife.com" (PDF). Retrieved 2012-05-05.
  25. ^ "Airdisaster.com". Airdisaster.com. Retrieved 2012-05-05.
  26. ^ Aircraft safety: accident investigations, analyses, and applications By Shari Stamford Krause. Books.google.com. 2003-07-23. Retrieved 2012-05-05.
  27. ^ "NOVA/PBS.org: The final eight minutes". Pbs.org. 1977-03-27. Retrieved 2012-05-05.
  28. ^ JAR Professional Pilot Studies by Phil Croucher. books.google.com. Retrieved 2013-05-03.
  29. ^ Official report, p.48
  30. ^ Bruggink, Gerard M. "Remembering Tenerife". Retrieved 24 February 2014.
  31. ^ "Air travel's communications killer". Salon.com. 2002-03-28.
  32. ^ "Plane Crash Info, March 1977, page 18". Planecrashinfo.com. 1977-03-27. Retrieved 2012-05-05.
  33. ^ "Tenerife Disaster, 1977 Year in Review". Upi.com. 2012-04-30. Retrieved 2012-05-05.[dead link]
  34. ^ Fatal Events Since 1970 for KLM AirSafe.com.
  35. ^ Advertisement showing Veldhuyzen van Zanten, Project-Tenerife.
  36. ^ Jan Reijnoudt en Niek Sterk: Tragedie op Tenerife: de grootste luchtramp, optelsom van kleine missers, 2002. ISBN 9043505633
  37. ^ "Crash of the Century." Cineflix Productions.
  38. ^ Template:PDF, pp. 61–62
  39. ^ a b Nicholas Faith (1996, 1998). Black Box: pp.176–178
  40. ^ Washington Post, March 25, 1980
  41. ^ Template:PDF, p. 2 (PDF page 6 of 97). "The study group notes with approval that the official report of the spanish government has, itself, included a section on human factors involved in this accident. We feel that this is an excellent beginning toward a better understanding of the causal factors of aviation accidents, an idea whose time has finally come."
  42. ^ Template:PDF, section 5.2, p. 38 (PDF page 41 of 63): "...these circumstances could have induced the co-pilot not to ask any questions, assuming that his captain was always right"
  43. ^ Bartelski, Jan (2001). Disasters in the air: mysterious air disasters explained. Airlife. ISBN 978-1-84037-204-5. As far as the allegations that co-pilots would not have the nerve to stand up to van Zanten during flight because of his senior position in the company, and that their career could be ruined by his adverse report, this was another example of completely false presumptions. Van Zanten was a serious and introverted individual but with an open-hearted and friendly disposition. He was a studious type and was regarded as the company's pilot expert on the Boeing 747 systems. Nevertheless, he would have been the last person on the flight desk not to accept his co-pilot's advice or warning. He believed in partnership, to the extent that he insisted on his first officers addressing him during flight as «Jaap» and not «Captain van Zanten». He had learnt much about cockpit management by representing KLM at an IATA Conference in Istanbul and was trying to put this into practice ... Meurs was not the type to have been easily intimidated by a superior rank and would not have easily given in under stress. Although new to the 747 (he had only ninety hours on that type), he was formerly a temporary DC8 captain. For personal reasons, he waived his seniority right for a DC9 command and opted to fly the 747 as a first officer. Meurs was an extrovert and liked to enjoy life, a contrasting disposition to van Zanten. Both complemented each other in personalities as well as in their operational background. What van Zanten lacked in route experience, particularly in the Canary Islands area, Meurs compensated for by his ultimate knowledge of the local situation from his many past flights through Las Palmas. The reverse applied to the handling of the 747. As for his profiency as a co-pilot, I found Meurs cooperative, alert, and far from a meek and mild type. In fact, the opposite was more likely. He could be somewhat abrupt and direct in his manner, as was evident from the way he stopped van Zanten from opening the throttles {{cite book}}: Cite has empty unknown parameter: |coauthors= (help); line feed character in |quote= at position 886 (help)
  44. ^ Template:PDF, p. 22 (PDF page 26 of 97). "Both pilots were contending with heavy demands on their attention as the visibility rapidly worsened. The flight engineer, to the contrary, had completed the heaviest part of his workload and was now reverting to an instrument monitoring mode."
  45. ^ Template:PDF, p. 22 (PDF page 26 of 97). "It is our opinion that the flight engineer, like the pilots, did not perceive the message from the controller to the Pan Am asking them to report when runway clear. (Because of the use of the address "Papa Alpha)."
  46. ^ This Spanish report[dead link] says 55,500 liters of jet fuel. Based on a density of 0.8705 kg/l that weighs some 45 metric tons, or 49 US tons
  47. ^ The 55 tons of fuel the Dutch plane had taken on creates a massive fireball that seals the fate of everyone onboard NOVA | The deadliest plane crash, transcript
  48. ^ The extra fuel prolonged the fire, gifteddevil16 on Tenerife 1977
  49. ^ The full load of new fuel ignited immediately, Crossroads Today
  50. ^ CAP 413 Radio Telephony Manual (Edition 15), chapter 2 page 6
  51. ^ Helmreich, R. L.; Merritt, A. C.; Wilhelm, J. A. (1999). "The Evolution of Crew Resource Management Training in Commercial Aviation" (PDF). Int. J. Aviat. Psychol. 9 (1): 19–32. doi:10.1207/s15327108ijap0901_2. PMID 11541445.
  52. ^ "San Jose Inside – Dutch Hamann – Part 2". Sanjoseinside.com. 2006-01-23. Retrieved 2012-05-05.

External links

Wikimedia Commons has media related to Tenerife airport disaster.
External images
image icon PH-BUF (KLM 4805) - Airliners.net
image icon N736PA (Pan Am 1736) - Airliners.net

28°28′54″N 16°20′18″W / 28.48165°N 16.3384°W / 28.48165; -16.3384

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