Tenerife airport disaster
| File:Tenerife Disaster Collision aftermath 27 March 1977.jpg Pan Am 1736 ablaze after its collision with KLM 4805 | |
| Occurrence | |
|---|---|
| Date | March 27 1977 |
| Summary | Runway collision |
| Site | Tenerife, Canary Islands, Spain |
| Aircraft type | Boeing 747-121 |
| Aircraft name | Clipper Victor |
| Operator | Pan American World Airways |
| Registration | N736PAdisaster[1] |
| Passengers | 380 |
| Crew | 16 |
| Fatalities | 583 |
| Injuries | 61 |
| Survivors | 61 |
The Tenerife disaster took place on March 27, 1977, at 17:06:56 local time (also GMT), when two Boeing 747 airliners collided at Los Rodeos Airport on the island of Tenerife, Canary Islands, Spain, killing 583 people. The accident still has the highest number of fatalities (excluding ground fatalities) of any single accident in aviation history.
The aircraft involved were Pan Am Flight 1736, named Clipper Victor, under the command of Captain Victor Grubbs, and KLM Royal Dutch Airlines Flight 4805, named Rijn (Rhine River), under the command of Captain Jacob Veldhuyzen van Zanten. KLM 4805, taking off on the only runway of the airport, crashed into the Pan Am aircraft which was taxiing on the same runway.
Los Rodeos Airport (then TCI, now TFN) is situated in the northern part of Tenerife, and is used mainly for flights within the Canary Islands and flights from the Spanish mainland.
Terrorist bomb threat
Pan Am Flight 1736 had taken off from Los Angeles International Airport with an intermediate stop at New York's JFK International Airport. The aircraft was a Boeing 747-121, registration N736PA. KLM Flight 4805, a charter flight from the Netherlands, had taken off four hours before from Amsterdam Schiphol Airport. The destination of both planes was Las Palmas on Gran Canaria.
Upon contacting Gran Canaria International Airport, the Pan Am flight was told that the airport was temporarily closed due to a terrorist bomb attack by Canary Island separatists. A bomb had exploded in the airport concourse, injuring several people, and a threat of a second bomb had been received. Although the Pan Am crew indicated that they would prefer to circle until landing clearance was given, the plane was ordered to divert to Los Rodeos airport on the nearby island of Tenerife, together with many other planes. The KLM aircraft was also given instructions to divert to Los Rodeos.
In 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 them. The diverted aircraft 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.
Chain of events leading to disaster
Refueling
After 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 refueling vehicle obstructed the way to the active runway. Captain van Zanten had decided to refuel at Los Rodeos instead of Las Palmas, apparently to save time. The refuelling was to take an estimated 35 minutes.[3]
Taxiing and weather conditions
Following the tower's instructions, the KLM aircraft was cleared to taxi to the end of the only runway and make a 180 degree turn (in aviation terms this is called a 'backtaxi', or 'backtrack', and is difficult with a 747 on the narrow runway). While KLM 4805 was backtaxiing on the runway, 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 lined up in the direction of takeoff on Runway 30. During taxiing, the weather deteriorated. Fog had limited the visual range to 1000 feet (300 meters).
Pan Am was instructed to taxi along the same runway and take the third exit on their left, leaving the main runway, and head to the parallel taxiway. As the exits were not visually numbered or marked and the Pan Am airport chart did not designate the exits by number,[4] there was a degree of confusion in the Pan Am cockpit as to whether the control tower meant exit C3 or literally the third exit on their left,[5] as when this instruction had been received, the 747 was already past exit C1. Upon viewing their airport maps, the crew realized that leaving the runway at exit C3 would mean a 135° left turn onto the exit, and a 135° right turn onto the taxiway (for a simplified map of the runway and exits see Collision).
Since this maneuver is a difficult task for a 747 on an undersized airport, analysis of the cockpit voice recorder (CVR) recording suggests that the crew assumed that Tenerife ATC must have ordered them to turn at the next exit, C4, which was only 45°.
Communication problems
Immediately after lining up, the KLM captain powered up the 747 to take off; however, the co-pilot advised the captain that ATC clearance had not been given and takeoff was aborted instantly. The KLM crew then received an ATC airways clearance; a clearance to fly a certain route after take-off, but not permission for the take-off itself. The captain may have mistaken this for a take-off clearance. He released the brakes of the aircraft and the co-pilot responded with a heavy Dutch accent with words that could either be "We are at take off" or "We are taking off".[4] The control tower was confused by the message and asked for the KLM plane to stand by. However, simultaneous communication from Pan Am caused mutual interference. All that was audible was a heterodyne beat tone, making the tower response inaudible to the pilots. Coincidentally, Pan Am was reporting they had not finished taxiing. Either message, if broadcast separately, would have given the KLM crew time to abort its takeoff.
Due to the fog, the KLM crew was not able to see the Pan Am 747 taxiing 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.
While the KLM crew had started its take-off run, 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, the KLM flight engineer expressed his concern about the Pan Am not being clear of the runway, repeating this concern a few seconds later, but he was overruled by the captain. The flight engineer did not explicitly challenge him on this decision.
Final radio transmissions
At 4:58 p.m. on March 27, 1977, when this transcript begins, the KLM and Pan Am 747s are both in queue to taxi down the runway and turn around for takeoff; both could not see each other in the fog. Some back-and-forth occurs initially about what Air Traffic Control considers the best way to get the KLM plane into position for takeoff, but ultimately the controllers decide to send it taxiing straight down the runway. This led to a big mistake...
1658:14.8
KLM RT Approach KLM 4805 on the ground in Tenerife.
1658:21.5
APP KLM—ah—4805, roger.
1658:25.7
KLM RT We require backtrack on 12 for takeoff Runway 30.
1658:30.4
APP Okay, 4805 ... taxi ... to the holding position Runway 30.
Taxi into the runway and—ah—leave runway (third) to your left.
1658:47.4
KLM RT Roger, sir, (entering) the runway at this time and the first (taxiway) we, we go off the runway again for the beginning of Runway 30.
1658:55.3
APP Okay, KLM 80—ah—correction, 4805, taxi straight ahead—ah—for the runway and—ah—make—ah—backtrack.
1659:04.5
KLM RT Roger, make a backtrack.
1659:10.0
KLM RT KLM 4805 is now on the runway.
1659:15.9
APP 4805, roger.
1659:28.4
KLM RT Approach, you want us to turn left at Charlie 1, taxiway Charlie 1?
1659:32.2
APP Negative, negative, taxi straight ahead—ah—up to the end of the runway and make backtrack.
1659:39.9
KLM RT Okay, sir.
1701:57.0
PA RT Tenerife, the Clipper 1736.
1702:01.8
APP Clipper 1736, Tenerife.
1702:03.6
PA RT Ah—we were instructed to contact you and also to taxi down the runway, is that correct?
1702:08.4
APP Affirmative, taxi into the runway and—ah—leave the runway third, third to your left, [background conversation in the tower].
1702:16.4
PA RT Third to the left, okay.
1702:18.4
PA 3 Third, he said. PA? Three.
1702:20.6
APP [Th]ird one to your left.
1702:21.9
PA 1 I think he said first.
1702:26.4
PA 2 I'll ask him again.
1702:32.2
PA 2 Left turn.
1702:33.1
PA 1 I don't think they have takeoff minimums anywhere right now.
1702:39.2
PA 1 What really happened over there today?
1702:41.6
PA 4 They put a bomb (in) the terminal, sir, right where the check-in counters are.
1702:46.6
PA 1 Well, we asked them if we could hold and—uh—I guess you got the word, we landed here...
1702:49.8
APP KLM 4805 how many taxiway—ah—did you pass?
1702:55.6
KLM RT I think we just passed Charlie 4 now.
1702:59.9
APP Okay ... at the end of the runway make 180 [degree turn] and report—ah—ready—ah—for ATC clearance. [background conversation in tower]
1703:09.3
PA 2 The first one is a 90-degree turn.
1703:11.0
PA 1 Yeah, okay.
1703:12.1
PA 2 Must be the third ... I'll ask him again.
1703:14.2
PA 1 Okay.
1703:16.6
PA 1 We could probably go in, it's ah...
1703:19.1
PA 2 You gotta make a 90-degree turn.
1703:21.6
PA 1 Yeah, uh.
1703:21.6
PA 2 Ninety-degree turn to get around this ... this one down here, it's a 45.
1703:29.3
PA RT Would you confirm that you want the Clipper 1736 to turn left at the third intersection? ["third" drawn out and emphasized]
1703:35.1
PA 1 One, two.
1703:36.4
APP The third one, sir, one, two, three, third, third one.
1703:38.3
PA ? One two (four).
1703:39.0
1703:39.2
PA 1
PA RT
Good.
Very good, thank you.
1703:40.1
PA 1 That's what we need right, the third one.
1703:42.9
PA 3 Uno, dos, tres.
1703:44.0
PA 1 Uno, dos, tres.
1703:44.9
PA 3 Tres—uh—si.
1703:46.5
PA 1 Right.
1703:47.6
PA 3 We'll make it yet.
1703:47.6
APP ...er 7136 [sic] report leaving the runway.
1703:49.1
PA 2 Wing flaps?
1703:50.2
PA 1 Ten, indicate 10, leading edge lights are green.
1703:54.1
PA ? Get that.
1703:55.0
PA RT Clipper 1736.
1703:56.5
PA 2 Yaw damp and instrument?
1703:58.6
PA 1 Ah—Bob, we'll get a left one...
1703:59.3
PA 2 I got a left.
1704:00.6
PA 1 Did you?
1704.00.9
PA 2 And—ah—need a right.
1704:02.6
PA 1 I'll give you a little...
1704:03.8
PA 2 Put a little aileron in this thing.
1704:05.0
PA 1 Okay, here's a left and I'll give you a right one right here.
1704:09.7
PA 1 Okay, right turn right and left yaw.
1704:11.4
PA 2 Left yaw checks.
1704:12.4
PA 1 Okay, here's the rudders.
1704:13.6
PA 1 Here's two left, center, two right center.
1704:17.8
PA 2 Checks.
1704:19.2
PA 2 Controls.
1704:19.6
PA 1 Haven't seen any yet!
1704:20.3
PA 2 I haven't either.
1704:21.7
PA 1 They're free, the indicators are checked.
1704:24.6
PA 2 There's one.
1704:25.8
PA 1 There's one.
1704:26.4
PA 1 That's the 90-degree.
1704:28.5
PA ? Okay.
1704:34.5
PA 2 Weight and balance finals?
1704:37.7
[Sounds similar to stabilizer trim]
1704:37.2
PA 1 We were gonna put that on four and a half.
1704:39.8
PA 3 We got four and a half and we weigh 534. [sound of stabilizer trim]
1704:44.6
PA 2 Four and a half on the right.
1704:46.8
PA 2 Engineer's taxi check.
1704:48.4
PA 3 Taxi check is complete.
1704:50.5
PA 2 Takeoff and departure briefing?
1704:52.1
PA 1 Okay, it'll be standard. We gonna go straight out there till we get 3,500 feet, then we're gonna make that reversal and go back out to ... 14.
1704:58.2
APP [KLM] 8705 [sic] and Clipper 1736, for your information, the centerline lighting is out of service. [APP transmission is readable but slightly broken]
1705:05.8
KLM RT I copied that.
1705:07.7
PA RT Clipper 1736.
1705:09.6
PA 1 We got centerline markings (only) [could be "don't we"] they count the same thing as ... we need 800 meters if you don't have that centerline ... I read that on the back (of this) just a while ago.
1705:22.0
PA 1 That's two.
1705:23.5
PA 3 Yeah, that's 45 [degrees] there.
1705:25.7
PA 1 Yeah.
1705:26.5
PA 2 That's this one right here.
1705:27.2
PA 1 [Yeah], I know.
1705:28.1
PA 3 Okay.
1705:28.5
PA 3 Next one is almost a 45, huh, yeah.
1705:30.6
PA 1 But it goes...
1705:32.4
PA 1 Yeah, but it goes ... ahead, I think (it's) gonna put us on (the) taxiway.
1705:35.9
PA 3 Yeah, just a little bit, yeah.
1705:39.8
PA ? Okay, for sure.
1705:40.0
PA 2 Maybe he, maybe he counts these (are) three.
1705:40.0
PA ? Huh.
1705:44.8
PA ? I like this.
In the final minute before the collision, key misunderstandings occur among all the parties involved. And in the end, the KLM pilot initiates takeoff, even though Air Traffic Control has not issued the proper clearance.
1705:41.5
KLM 2 Wait a minute, we don't have an ATC clearance.
KLM 1 No, I know that. Go ahead, ask.
1705:44.6
KLM RT Uh, the KLM 4805 is now ready for takeoff and we're waiting for our ATC clearance.
1705:53.4
APP KLM 8705 [sic] uh you are cleared to the Papa beacon. Climb to and maintain flight level 90 ... right turn after takeoff proceed with heading 040 until intercepting the 325 radial from Las Palmas VOR.
1706:09.6
KLM RT Ah, roger, sir, we're cleared to the Papa beacon flight level 90, right turn out 040 until intercepting the 325, and we're now (at takeoff).
1706:11.08
[Brakes of KLM 4805 are released.]
1706:12.25
KLM 1 Let's go ... check thrust.
1706:14.00
[Sound of engines starting to accelerate.]
1706:18.19
APP Okay.
1706:20.08
APP Stand by for takeoff ... I will call you. PA1 No, uh.
PA RT And we are still taxiing down the runway, the Clipper 1736.
1706:25.47
APP Ah—Papa Alpha 1736 report runway clear.
1706:25.59
PA RT Okay, we'll report when we're clear.
1706:31.69
APP Thank you.
1706:32.43
KLM 3 Is he not clear, then?
1706:34.10
KLM 1 What do you say?
1706:34.15
PA ? Yup.
1706:34.70
KLM 3 Is he not clear, that Pan American?
1706:35.70
KLM 1 Oh, yes. [emphatically]
"There he is ... look at him! Goddamn, that [expletive deleted] is coming straight at us!" "Get off! Get off! Get off!" 1706:47.44, the KLM pilot screams, and the collision occurs.
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 C4. The Pan Am crew applied full power and took a sharp left turn onto the exit to avoid a collision. The KLM plane attempted to avoid a collision by climbing away, scraping the tail of the plane along the runway for 20 metres (65 ft). 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. The KLM plane then slammed into the ground belly-up 150 m past the point of collision and slid down the runway.
All 234 passengers and 14 crew members in the KLM plane were killed, and 326 passengers and 9 crew members aboard the Pan Am flight perished, primarily due to the fire and explosions resulting from the fuel spilled in the impact. Fifty-six passengers and 5 crewmembers aboard the Pan Am aircraft survived, including the Captain, First Officer, and Flight Engineer. Most of the survivors on the Pan Am aircraft were able to walk out onto the left wing through holes in the fuselage structure. At least one passenger stated that the 747's engines were still running for a few minutes after the accident. Survivors waited for rescue, but it didn't 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 jumped to the ground below. The only member of the KLM passenger manifest to avoid the disaster was Robina van Lanschot, a travel guide who lived on Tenerife and elected not to reboard the 747 when it was due to depart.[3]
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 take-off, while the Tenerife control tower was certain that the KLM 747 was stationary at the end of the runway and awaiting takeoff clearance.
Probable cause
While there is disagreement about their relative importance, the investigation concluded that the major causal factors of the accident were:
- KLM mistakenly took off without a take-off clearance.
- The KLM captain did not interrupt take-off when the Pan Am crew reported that they were still on the runway.
- The KLM captain's emphatic affirmative in reply to the KLM flight engineer's query as to whether the Pan Am plane had already left the runway.
- Squelched radio messages (two calls between the planes and the control tower interfered with each other because they happened at precisely the same instant).
- Pan Am mistakenly continued to exit 4 instead of exiting at number 3 as directed by ATC.
- Use of ambiguous non-standard phrases by the KLM co-pilot ("We're at take off") and the Tenerife control tower ("O.K.").
- The airport, designed to handle smaller aircraft like the Boeing 737, was (due to rerouting from the bomb threat) forced to accommodate a large number of larger aircraft, resulting in disruption of the normal use of taxiways.
Speculations
Experts speculated about other contributing factors:
- 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. He may have suffered from 'training syndrome', having been in charge of everything at the simulator (including simulated ATC), and having been away from the real world of flying for extended periods.[3]
- The flight engineer's apparent hesitation to further challenge van Zanten, possibly because van Zanten was not only senior in rank, but also one of the most able and experienced pilots working for the airline.[3]
- The possibility that van Zanten was in a hurry to commence the delayed flight due to Dutch regulations on exceeding crew duty hours.[6]
- The use of an unsafe procedure. An Air Traffic Control clearance by a control tower issued under no-visibility conditions is not a safe procedure as such a clearance is based on visual contact. However, most authorities allow control to continue based entirely on reports from pilots, who do not have visual contact either. Although this practice still occurs in some countries, it is increasingly being abandoned and superseded by the installation of surface movement radar. It has also been revealed that some countries do not conform entirely with international standards concerning poor visibility conditions. Some tower units accept it under the strict condition that only one aircraft is operating on the runway, while taxiing to and from it is done by using a vehicle called a "follow-me car" moving slowly ahead of the plane, leading the pilot. (The unsafe nature of the procedure that caused the accident in Tenerife was verified in a bitter way some 25 years later in what became known as the Linate Airport disaster at Milano Linate International Airport on October 8, 2001, when Flight SAS686, an MD-87 airliner, was cleared for take-off based on the report of a private jet plane (a German Cessna Citation) pilot that erroneously followed a different taxiway under zero visibility conditions, which did not allow a visual verification by the tower. The MD-87 collided with the Cessna that was crossing the runway and came down on aerodrome buildings, resulting in the deaths of 118 people.)[7]
There was some disagreement between the various investigative bodies, with the Dutch investigators accusing the Spaniards of listening to a soccer game and accusing the Americans of being at fault for staying on the runway. However, both the Spanish and American investigations pointed the finger mostly at the KLM crew.[6]
Safety response
As a consequence of the accident, there were sweeping changes 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 take-off. The FAA equivalent is "taxi into position and hold". Air traffic instruction should not be acknowledged solely with a colloquial phrase such as "OK" or even "Roger", but with a read back of the key parts of the instruction, to show mutual understanding. Additionally the phrase "take-off" is only spoken when the actual take-off clearance is given. Up until that point both aircrew and ATCOs should use the phrase "departure" in its place (e.g. "ready for departure").
Cockpit procedures were also changed. Hierarchical relations among crewmembers were played down. More emphasis was placed on decision-making by mutual agreement. This is known in the industry as crew resource management, and is now standard training in all major airlines.
Due to the frequent and dangerous fogs that cover the area around Los Rodeos airport in the North of the island, a second airport was built in the South of the Island: the new Reina Sofía Airport. This airport serves the majority of Tenerife's domestic and international commercial flights.
The Spanish authorities have installed a ground radar at Los Rodeos following the accident. Dedicated to regional flights following the accident, Los Rodeos has seen return of international flights due to the growing tourist traffic.
Memorials
A memorial and final resting place for the victims of the KLM plane is located in Amsterdam, at Westgaarde cemetery. There is also a memorial in Westminster, California. A memorial was dedicated at Tenerife airport on March 27, 2007. The 30th anniversary marks the first time that Dutch and American next of kin have joined in a ceremony.
Miscellaneous
- Captain van Zanten was the preferred pilot for KLM publicity, such as magazine ads.
- Van Zanten had given the first officer on the accident flight, Klaas Meurs, his B747 qualification check about 2 months before the accident at Tenerife.
- Clipper Victor (ex-Clipper Mayflower and Clipper Young America), N736PA, was the first jumbo to carry fare-paying passengers, replacing the original Clipper Young America, N733PA, at the last minute due to the latter's engine problems, on Pan Am's maiden 747 passenger flight from New York to London on January 22, 1970.[3]
Well-known people who were killed in the disaster were:
- Eve Meyer, a pin-up model, film actress and producer and former wife of Russ Meyer.
- A. P. Hamann, the former city manager of San Jose, California, and his wife Frances Hamann.
See also
- List of accidents and incidents on commercial airliners grouped by year
- Air Crash Investigation
- The 2005 Logan Airport runway incursion, where there was almost a similar disaster
Notes
- ^ "FAA Registry (N736PA)". Federal Aviation Administration.
- ^ "Civil aircraft register (PH-BUF)". Inspectie Leefomgeving en Transport.
- ^ a b c d e Macarthur Job (1995). Air Disaster Volume 1: pp.165-180
- ^ a b "Air Line Pilot, August 2000, p.18".
- ^ "NOVA:The Deadliest Plane Crash - The Final Eight Minutes". PBS. Retrieved 2006-10-19.
- ^ a b Nicholas Faith (1996, 1998). Black Box: pp.176-178
- ^ "Aviation Safety Network (SAS 686)". Flight Safety Foundation. Retrieved 2006-11-13.
References
- Report from Pan Am site
- Coverage from Air Safety Network site (Pan Am 1736)
- Coverage from Air Safety Network site (KLM 4805)
- AirDisaster.com Accident Database (Pan Am 1736)
- AirDisaster.com Accident Database (KLM 4805)
- ICAO document mentioning phrasing used in the accident
- Air Line Pilot, August 2000, page 18
External links
- ASN Pan Am N736PA Accident Description
- ASN KLM PH-BUF Accident Description
- BBC report with news report
- ICAO document mentioning phrasing used in the accident
- Comprehensive account of collision
- 1001 Crash - A complete story of the Tenerife disaster : This story includes DFDR transcriptions, and pictures taken the day of the tragedy
- Airmanship Online - a detailed account of the tragedy
- NOVA "The Deadliest Plane Crash" - Homepage to the NOVA TV episode
- Tenerife Memorial
- Project Tenerife
- PlaneCrashInfo.Com - Tenerife Disaster
- Ask the Pilot on the Tenerife disaster Patrick Smith, Salon.com