Investigación del accidente de Los Rodeos 27 Marzo 1977

On 27 March 1977 the collisión of the 747s the at Tenerife

REPORT

Special report Publisher on December 2004 concerning the truth about this accident and the responsible people.

GENERAL  SECRETARY  PUBLICATIONS

English

Bibliography

TENERIFE .  AVIATION DISASTER,  27.03.1977 Los Rodeos Airport

American Airlines Pilot's Association  (ALPA)

Air Disasters: Dialogue from the Black Box

Stanley Stewart, 1986

Spanish: “Subsecretaría Aviación Civil", Accident Report, 1978 ( ICAO CIRCULAR AN-/56). Madrid.

 *  *  *

MOVIMIENTO POR LA AUTODETERMINACIÓN Y LA

INDEPENDENCIA DEL ARCHIPIÉLAGO CANARIO

M.P.A.IA.C.

NOTA: Se adjunta las declaraciones del piloto jubilado de la Cía. Española IBERIA, responsable de la investigación del accidente de Los Rodeos en 1976, aparecidas en el periódico de Tenerife, "El Día", en fecha del 9 de enero del 2005, Don JAIME VELARDE SILIO, actualmente retirado, donde podrán comprobar que este profesional español no dice la verdad sino que le echa toda la culpa al avión de la KLM , sin tener en cuenta que en su día la ALPA y la lectura de las cajas negras le echaba la culpa a la torre de control de Los Rodeos en un porcentaje del 30 % y a los controladores. El gobierno español tuvo que pagar el 30 % de las indemnizaciones millonarias a las familias de los pasajeros por las faltas cometidas por los controladores españoles, llegando incluso a insinuar la ALPA , que el controlador de servicio estaba viendo un partido de fútbol en la TV mientras dirigía las operaciones y que empleaba una sola micro para los dos aviones con una misma frecuencia y que sus conocimientos del inglés eran muy malos.

Leer las reproducciones de las conversaciones de las Cajas Negras y las consideraciones de la ALPA sobre el accidente y a quienes echan la culpa y comparen con las declaraciones de D. Jaime Velarde y de toda la prensa de la época, queriendo culpar a nuestro Movimiento, el cual no tuvo nada que ver con este accidente ni de cerca ni de lejos, ni directa ni indirectamente, incluso con el incidente del aeropuerto de Gando en Las Palmas, del cual se nos quiso acusar, sin que nunca hallaran a los supuestos responsables.

*  *  *

Jaime Velarde Silió:

PILOTO JUBILADO DE IBERIA Y RESPONSABLE DE LA INVESTIGACIÓN DEL ACCIDENTE AÉREO DE LOS RODEOS

"En los accidentes aéreos no hay culpables,

sí responsables"

CLAUDIO ANDRADA, S/C. Tfe, 9 enero 2005

Aunque lo pareciera, el domingo del día 27 de marzo de 1977 no terminaría para Juan Velarde como otro día festivo cualquiera. A las 17:06 horas GMT, momento en que disfrutaba con su familia en las afueras de Madrid de su merecido descanso, este piloto de Iberia (en la actualidad de 71 años y jubilado, aunque sigue volando aparatos de época junto a su hijo, de idéntica profesión) no podía imaginar que a la llegada a su domicilio un mensaje reclamaba su presencia porque se había producido el que hasta la actualidad (da gracias a Dios de que así sea) ha sido el accidente aéreo con mayor número de víctimas mortales: el registrado en Los Rodeos, en el que perecieron 583 personas por la colisión de dos Boeing 747, uno de la compañía holandesa KLM y otro de la americana Pan Am.

Precisamente porque mañana, lunes, Nat Geographic, de Digital + ofrece a las 14:00, 19:00 y 23:00 horas un reportaje alusivo a la tragedia, EL DÍA logró entrevistar a este piloto de Iberia que conoce de primera mano qué sucedió y cómo se vivieron los momentos posteriores al terrible accidente aéreo. No en vano fue comisionado para que se encargara de la investigación oficial por parte de la asociación de pilotos que existía en aquella época.

-¿Por qué lo llamaron a usted para hacerse cargo de la investigación?

-Estaba especializado por cuenta de la asociación de pilotos españoles en la investigación de accidentes aéreos, ya que había realizado un curso en la universidad del Sur de California, aunque en realidad mi mayor y primera experiencia fue precisamente ésta. No tuve mucha suerte.

-Y con el aeropuerto de Los Rodeos cerrado, ¿cómo llegó a Tenerife?

-La asociación me dijo que me buscara la manera de llegar, y yo sabía que el tiempo corría en contra, ya que la propia actuación de los servicios de emergencia podían borrar pistas clave. Salí esa misma noche en un Iberia que iba a Caracas, vía Gran Canaria, y el único medio que existía era un helicóptero. Dio la casualidad que conocía al piloto y le rogué que me desplazara a Tenerife. Me fui como teórico mecánico de vuelo y me puse el mono. Llegué a las 5 de la mañana, aún sin amanecer, con niebla cerrada, y aún quedaban rescoldos, sobretodo de la avión de la KLM y me puse manos a la obra.

-¿Qué fue lo que más lo impresionó al presenciar lo que se le venía encima?

-Era espeluznante. Se percibía la tragedia por la tristeza en los rostros de la gente y un olor ocre que impresionaba enormemente. Y sin darle coba a los tinerfeños, tengo que decir que la respuesta solidaria fue de tal magnitud que hubo que emitir un bando por la radio para rogar que dejaran de donar sangre porque la cantidad era tal que colapsaba las entradas al recinto portuario. Impresionante.

-¿Cuáles fueron los primeros pasos en la investigación?

-Eso lo tenía muy claro. Croquis, fotografías, dibujos de los restos principales... lo antes posible, y lo segundo, afrontar la situación y responder a lo que recomienda la asociación internacional de pilotos para ponerme a disposición de la tripulación afectada, que estaba en el hospital.

-¿Hubo cortapisas para la investigación o presiones?

-La situación en España era dificilísima, ya que la estructura pertenecía al ejército del Aire, de hecho me llamó el general Franco Iribarne Garai y fue muy valiente, porque mandó la investigación a EEUU, donde se llevó a cabo. Le mostré mi disponibilidad y se buscó la verdad. Todo un orgullo.

-¿Y hacia dónde fue la culpa?

-En un accidente aéreo no hay una sola causa y no hay culpables, sino un cúmulo de causas y responsables. Lo cierto es que hubo una responsabilidad del piloto de la holandesa KLM, una de las compañías más prestigiosas y pionera de Europa.

-La realidad es que a España no le cayó nada...

-Sí, pero en la búsqueda de la verdad, tras dos años de investigaciones, las presiones de Holanda fueron muchas. Pero lo que nos preocupaba era llegar a qué fue lo que pasó, y la responsabilidad llegó a señalar sin lugar a dudas al piloto de la KLM.

-¿Cuándo se supo que la responsabilidad no era española?

-Aunque siguieron las investigaciones dos años más en EEUU, nosotros, no como investigadores sino como españoles, tras oír las "cajas negras" con las conversaciones de las dos naves y los controladores supimos que la responsabilidad fue del piloto de KLM.

LA CLAVE

"Buscamos siempre la verdad"

Cuando se presentaron las primeras conclusiones, una vez oídas las "cajas negras" de los dos aparatos siniestrados, Velarde confiesa que "la parte holandesa, precisamente de una de las compañías más antiguas y prestigiosas de Europa, trataron de hallar alguna responsabilidad en la comunicación de los controladores que operaban en aquel momento en el aeropuerto de Los Rodeos, pero -añade- la labor de los mismos fue impecable, incluso por encima del nivel, ya que el aluvión de tráfico que les llegó de repente, merced al cierre por un atentado del MPAIAC del aeropuerto de Gando, fue impresionante". Apostilla Jaime Velarde que buscaban la verdad como única opción y b "estaba dispuesto a fijar responsabilidades donde las hubiera, incluso en contra de los intereses de España si así hubiera sido, aunque después pudieran machacarme (sonríe), pero la realidad es que la responsabilidad fue un fallo clamoroso del piloto de la compañía KLM, que no esperó la autorización de la torre y puso los motores a tope para despegar, y pasó lo que pasó; pero también había niebla, y hubo un leve corte en las comunicaciones... La cierto es que cuando sucede un accidente así nunca se produce por una sola causa, sino por una suerte de infortunios", aclara el veterano piloto.

Publicado en el periódico El Día, 9 enero 2005

* * *    

English

Bibligraphy  

                                    TENERIFE . AVIATION DISASTER, 27.03.1977

                                    Los Rodeos Airport.

                                    American Airlines Pilot's Association (ALPA)

                                    Air Disasters: Dialogue from the Black Box Stanley Stewart, 1986

                                    Spanish Subsecretaría Aviación Civil", Accident Report,1978

                                    (ICAO CIRCULAR AN-/56). Madrid.

* * *

Abbreviations and Glossary

AINS        Area Inertial Navigation System

ASR         Área Surveillance Radar

ATC         Air Traffic Control

BEA         British European Airways 

CVR         Cockpit Voice Rccorder

FDR         Flight Data Recorder

F/E          Flight Engineer       

FIR          Flight Information Region

F/O          First Officer

GMT        Greenwich Mean Time

HF           High Frequency

IFR          Instrument Flight Rules

IMC         Instrument Meteorológical Conditions

INS          Inertial Navigation System

KLM        Koniges Lucht Macht — Royal Dutch Airlines

kt             knots

local         Local time if different to GMT

MHz         Megahertz

NDB         Non-Directional Beacon

nm            nautical mile

Phonetic   Alphabet used for clear and distinct spelling. This is also used as a

Alphabet  shorthand when referring to aircraft, so G-ARPI becomes ¨Papa India '

QNH        Mean Sea Level Altimeter Pressure Setting

R/T          Radio Telephony

rpm          revolutions per minute

S/O          Second Officer

Tel.          Telephone

V1            Decision speed - the go or no-go decision point on take-off

V2            Mínimum safe speed required in the air after an engine failure at VI

VFR         Visual Flight Rules

VHF         Very High Frequency

VMC        Visual Meteorological Conditions

VOR        VHF Omnidirectional range Radar beacon  

* * *

  

Pan American Flight PA1736, a Boeing 747 — registration N736PA — on charter to Royal Cruise Lines, departed Los Angeles on the evening of 26 March local date (01.29hrs GMT, 27 March) with 275 passengers for New York and Las Palmas. On the stop-over at JFK a further 103 passengers boarded, bringing the total to 378. The crew of 16 was changed. At 07.42hrs (all times GMT) Flight PA1736, call sign Clipper 1736, departed Kennedy for Las Palmas under the command of Captain Víctor Grubbs, with First Officer (F/O) Robert Bragg and Flight Engineer (F/E) George Warns. Tending the passengers' needs were 13 flight attendants. About 1 1/4 hours after the Clipper's take-off from New York , KLM Flight KL4805 departed from Amsterdam at 09.00hrs also en route to Las Palmas . The KLM Boeing 747, registration PH-BUF, was operated by the Dutch airline on behalf of Holland Internation travel group, and on board were 234 tourists bound for a vacation in the Canary Islands , plus one travel guide. After disembarking the passengers, PH-BUF was scheduled as Flight KL4806 to fly back to Amsterdam with an equally large group of returning holidaymakers. The Dutch crew rostered for the round trip was commanded by Captain Jacob van Zanten, a senior KLM training captain, and with him on the flight deck were F/O Klass Meurs and F/E William Schreuder. There were 11 cabin staff to look after the charter passengers.

As both Boeing 747s converged on Las Palmas , the bomb was detonated in the terminal building about one hour before KLM's arrival. With closure of the airport Flight KL4805 simply diverted to Los Rodeos on Tenerife pending the reopening of the airport, and landed at 13.38hrs GMT, the same time as local. At first Captain van Zanten was reluctant to disembark his passengers in case Las Palmas suddenly opened, but after 20 min of waiting he reversed his decision and buses arrived to transport the travellers to the terminal. Pan Am's arrival from New York was also affected, but since the opening of Las Palmas seemed imminent and they had adequate fuel, Captain Grubbs asked to hold at altitude near Tenerife . The request was refused and Flight PA1736 also landed at Los Rodeos at 14.15hrs, about 30min behind KLM. The weather was clear and sunny. Many aircraft were diverted from Las Palmas that day and, with Tenerife 's own week-end traffic, Los Rodeos was becoming overcrowded. To make use of all available space, aircraft were parked on the runway 12 holding area situated only a short distance from the main apron on the northern side of the runway. KLM was parked nearest the threshold of runway 12 followed in sequence by a Boeing 737, a Boeing 727, a DC-8 and the Pan Am Boeing 747 taking up the rear. These aircraft filled the holding area and subsequent arrivals were parked where space could be found on the main apron. Airport staff worked overtime to handle the doubled amount of traffic.

Meanwhile, the Dutch crew, concerned that there might be insufficient time for them to complete the round trip back to Holland ; contactad Amsterdam on high frequency long range radio. A few years before, a Dutch captain was able to extend the crew's duty day at his own discretion according to a number of factors which could be readily assessed on the flight deck. The situation was now infinitely more complex and crews were advised to liaise with Amsterdam in order to establish a limit to their duty day. Captains were bound by this limit and could be prosecuted under the law for exceeding their duty time. Amsterdam replied that if the KLM flight could depart Las Palmas by 19.00hrs at the latest they would not exceed their flight time limitation. This would be confirmed by a message in writing in Las Palmas .

Shortly after Pan Am's arrival, Las Palmas was declared open at about 14.30hrs and aircraft began to depart for Grand Canary Island . Since the Clipper charter flight's passengers were still on board they were prepared for a quick departure. Two company employees joined the flight in Tenerife for the short hop to Las Palmas and were placed in the jump seats on the flight deck, bringing the total on board to 396; 380 passengers and 16 crew. As the aircraft on the holding area positioned between the two 747s were permitted to depart, Pan Am called for clearance in turn. When start-up was requested the controller explained that although there was no air traffic delay they might have to wait. Taxying via the parallel taxi route past the main apron was not possible because of overcrowding, and the holding area exit on to the runway was probably blocked by KLM. The other aircraft parked on the holding area, being smaller in size, had managed to pass behind the KLM 747 on their departure for Las Palmas . Unable to follow suit, N736PA was trapped until the Dutch aircraft moved.

The KLM passengers were summoned from the terminal building, but it took time to bus them back to the aircraft and reboard the flight. Of those who landed in Tenerife only the Dutch company travel guide remained behind, giving a total on board of 248; 234 passengers and 14 crew. In the meantime, many aircraft were arriving at the reopened Las Palmas Airport and it, too, was becoming congested. Los Rodeos was co-ordinating the situation with Las Palmas personnel and soon news carne through of a further delay for the Dutch flight. As yet no gate was available for KLM and Captain van Zanten had no choice but to wait. The Dutch crew maintained cióse contact with Tenerife tower over their departure time and expressed concern over the delay. They had now been on the ground for over two hours. It was unlikely a speedy turn-round could be expected in Las Palmas owing to the congestión, so to ease the situation the Dutch captain made the somewhat late decisión to refuel at Tenerife . Since they were still awaiting departure clearance owing to the unavailability of the gate at Las Palmas it would save time on the transit to refuel there for the return Tenerife-Las Palmas-Amsterdam journey. The fuelling process, however, would take about 30min. The Pan Am crew, still hemmed in on both sides, was far from happy with this decision. N736PA was free to leave at any time but could not do so until KLM moved. The American first officer and flight engineer walked out on to the tarmac to measure the distance behind KLM but confirmed that there was insufficient space. Captain Grubbs had been listening in on KLM's radio conversation with the tower and knew of the Dutch captain's desire to leave as early as possible but, unaware of KLM's tight schedule, he felt the Dutch were further delaying both their departures unnecessarily. Clearance for Captain van Zánten to start could come through at any moment but would now have to wait completion of KLM's refuelling. To complícate matters the weather was beginning to deteriórate. Los Rodeos airport is situated at an elevation of 2,000ft in a kind of hollow between mountains and is frequently subject to the presence of low-lying cloud, reducing visibility. In fog, the moisture content and therefore visibility remains relatively constant, but with low cloud drifting across an airport the visibility can change rapidly from several kilometres to zero in a matter of minutes. There was a danger of the weather closing in and preventing departures for a long period. Clouds of varying density from light to dark were blowing down the departure runway 30 with the northwesterly 12 to 15kt wind. At times* the runway visibility increased to two or three kilometres and at other times dropped to 300m. The runway centre line lights were inoperaíive making judgement on take-off more difficult. There was also heavy moisture in the air with the passage of the clouds, and aircraft were frequently required to use their windscreen wipers to clear the view when taxying.

The time was now about 16.30hrs and the Pan Am crew had been on duty for 10³/4 hours. They were beginning to feel the strain and were looking forward to their rest after the short 25min hop to Las Palmas . The KLM crew had been on duty for 8% hours, but they still had to complete the round trip back to Amsterdam . Three hours remained to the deadline for departure out of Las Palmas , but with the weather worsening this time limit could easily be compromised if they had to wait for the clouds to clear. As it was, the duty limit had not yet been confirmed, and even with fuel on board the transit through Las Palmas could be slow in the overcrowded airport. If the crew ran out of hours and PH-BUF got stuck in Las Palmas , there would be more than a few problems for the ground staff. To begin with, it would be almost impossible to find 250 beds at such short notice and the joining passengers would probably have to spend the night in the airport. The crew would also be late back to Amsterdam and the aircraft would miss the next day's schedules. It was hardly surprising that the Dutch crew were keen to get away. The Americans, too, a little irritated at being held back by KLM, would also be happy to leave Los Rodeos behind.

Permission for KLM to depart did not come through until refuelling was almost finished and vindicated Captain van Zanten's decision to complete the process in Tenerife . As the Clipper crew waited, the American passengers were invited to view the flight deck, and questions about the flight were answered. At 16.45hrs Captain van Zanten signed the fuel log and at 16.51hrs, with pre-start checks completed, KLM requested start-up. Alert to the situation Pan Am heard KLM's radio call.

'Aha', said Captain Grubbs, 'he's ready!'

 The Clipper also received start clearance as KLM was starting engines and the two crews prepared to taxi. Owing to the prevailing northwesterly wind, both aircraft had to enter the runway from the holding area for runway 12 and taxi right to the far end of the ll,150ft (3,400m) runway, a distance of over two miles, for take-off in the opposite direction on runway 30.

At that time the control tower had three radio frequencies available of 121.7MHz, 118.7MHz and 119.7MHz. Only two controllers were on duty, however, and 118.7MHz was used for ground taxi instruction and 119.7MHz, the approach frequency, for both take-off and approach communication. KLM was cleared to taxi at 16.56hrs but was instructed to hold short of the runway 12 threshold and to contact approach on 119.7MHz. On establishing contact, Flight KL4805 requested permission to enter and back-track on runway 12. Clearance was received to taxi back down the runway and to exit at the third turn-off, then to continue on the parallel taxiway to the runway 30 threshold. The first officer mis-heard and read back 'first exit', but almost immediately the controller amended the taxi instruction. KLM was directed to back-track the runway all the way, then to complete a 180° turn at the end and face into the take-off direction. The first officer acknowledged the instruction but the Captain, now concentrating on more pressing matters, was beginning to overlook radio call. The visibility was changing rapidly from good to very poor as they taxied along the runway and it was proving difficult to ascertain position. The approach controller issuing taxi instructions could see nothing from the control tower so was unable to offer any help. One minute later the KLM Captain radioed the approach controller asking if they were to leave the runway at taxiway Charlie 1. Once more KLM were instructed to continue straight down the runway.

Pan Am received taxi instructions on the ground frequency of 118.7MHz and was also directed to hold at the 12 threshold. Captain Grubbs was happy to wait until after KLM's departure but almost immediately they were cleared to follow the Dutch flight. The instruction was given to back-track on the runway and leave by the third exit but because of the ground controller's heavy Spanish accent the crew had a great deal of trouble understanding the clearance. With better Communications the Captain might well have established his preference to hold position, but since several attempts were required to comprehend a simple direction it was obviously going to be easier to comply with the controller's wishes. Pan Am was given instructions to back-track on the ground frequency so the Dutch crew, already changed to approach, were at first unaware that the Americans were following behind. As Flight PA1736 began its journey down the runway, ground cleared Captain Grubbs to contact approach. At 17.02hrs KLM now heard the Pan Am crew call approach control and request confirmation of the back-track instruction.

'Affirmative', replied approach, 'taxi into the runway and leave the runway third, third to your left, third'.

By now the Americans had been on duty for over 11 1/4 hours and were feeling tired. The Dutch crew had been on duty for over 9 1/4 hours, of which about 3 1/4 hours had been spent waiting on the ground at Tenerife . The visibility began to drop markedly and fell to as low as l00m in the path of the two Boeing 747s taxying down the runway. It was difficult to spot the exits. Thick cloud patches at other parts on the airport reduced visibility right down to zero. All guidance was given via the radio as no one could see anyone else and Los Rodeos was not equipped with expensive ground radar. Captain van Zanten, when approaching taxiway Charlie 4, again asked his co-pilot if this was their turn off, but the first officer repeated that the instruction had been given to back-track all the way to the end. The KLM crew had switched on the wipers to clear the moisture and suddenly, through the mist, could see some lights. The first officer confirmed the sighting.

'Here comes the end of the runway.'

'A couple of lights to go', replied the Captain. Approach then called asking Flight 4805 to state its position.

17.02:50, Approach R/T: 'KLM 4805, how many taxiway did you pass?'

17.02:56, KLM 4805 R/T: 'I think we just passed Charlie 4 now.'

17.03:01, Approach R/T: 'OK. At the end of the runway make a 180 and report ready for ATC (Air Traffic Control) clearance.'

The KLM crew now asked if the centre line lights were operating and the controller replied he would check. The Americans were still not sure of the correct turn-off because of the language difficulties and once again asked for confirmation that they were to exit the runway at the third exit.

17.03:36, Approach R/T: 'Third one sir, one, two, three, third, third one.'

17.03:39, PA1736 R/T: 'Very good, thank you.'

Approach R/T: 'Clipper 1736, report leaving the runway'.

The Clipper replied with his call sign. As the Americans continued down the runway the taxi check was commenced. Instruments and flying controls were checked, the stabiliser was set and the flaps were positioned for take-off, etc. Meanwhile, the Pan Am crew were also trying to spot the turn-offs from the runway in order to count along to the third one, but were having a great deal of trouble in seeing properly. They passed and recognised the 90° taxi exit but were unable to see the taxiway markers so were unsure how many turn-offs they had passed. The allocated exit involved following a 'Z' shaped pattern to manoeuvre on to the parallel taxiway and was going to be difficult for the large Boeing 747 to negotiate. Finding Charlie 3 was also proving to be difficult since its shape was similar to Charlie 2.

As KLM approached the end of the runway the controller called both aircraft regarding the centre line lights.

Approach R/T: '-For your information, the centre line lighting is out of service.'

Each flight acknowledged in turn and checked the minimum visibility required for take-off in such circumstances. By now KLM was commencing the turn at the end of the runway and much was on the Captain's mind. Turning a large aircraft through  180° on  a narrow  runway  requires a degree of concentration and temporarily distracted the captain from other duties. The time was now almost 17.05hrs  and  the  restriction  for departure  out of Las  Palmas   was  rapidly approaching. If they didn't depart soon they could easily miss it. By good fortune the visibility had improved sufficiently for take-off and with a reduction in moisture the wipers were switched off. If they could get away quickly in the gap in the weather everything should be fine. As the take-off approached, the captain, having to concentrate on so many Ítems, ¨seemed a little absent from all that was heard on the flight deck'. He called for the check list.

KLM F/O: 'Cabin warned. Flaps set ten, ten.'

KLM F/E: 'Eight greens.'

KLMF/O: 'Ignition.'

KLM F/E: 'Is coming — all on flight start.'

KLMF/O:'Body gear.'

KLM F/E: 'Body gear OK?'

The turn was now almost complete with the aircraft lining up on runway 30. KLM Capt: 'Yes, go ahead .'

The visibility now improved to 900m, but a cloud could be seen ahead moving down the runway. There was just enough time to get away. The Pan Am aircraft was approaching exit Charlie 3 at this stage, half way along the 3,400m runway, but in the bad conditions was unobserved by KLM. Nothing could be seen of the locations of the 747s from the tower. The two aircraft faced each other unseen in the mist.

KLM F/O: 'Wipers on?'

KLM Capt: 'Lights are on.'

KLM F/O: 'No ... the   wipers?'

KLM Capt: 'No I'll wait a bit... if I need them I¨ll ask.'

KLM F/O: 'Body gear disarmed, landing lights on, check list completed.'

At 17.05:28 the captain stopped the aircraft'at the end of the runway and immediately opened up the throttles.

KLM F/O: 'Wait a minute, we don't have an ATC clearance.'

The KLM captain, being a senior training pilot, had a lack of recent route practice and was more used to operations in the simulator where he spent a great deal of his time. In the simulator radio work is kept to a minimum on the grounds of expediency in order to concentrate on drills and procedures, and take-offs are often conducted without any formalities. Such an oversight, although alarming, can perhaps be explained by the circumstances. On closing the throttles the captain replied, 'No, I know that, go ahead, ask'. The first officer pressed the button and asked for both the take-off clearance and the air traffic clearances in the same transmission.

KLM F/O R/T: 'KLM4805 is now ready for take-off and we are waiting for our ATC clearance.'

Pan Am arrived at exit Charlie 3 just as approach began to read back KLM's ATC clearance. Having miscounted the turn-offs, they missed their designated taxi route and continued on down the runway unaware of their mistake. They were still about l,500m from the threshold and out of sight of KLM. It was now over two minutes since the approach controller's last call to Pan Am requesting him to report leaving the runway, and in the KLM crew's desire to depart, the fact that Pan Am was still in front of them, not having cleared the runway, was being overlooked.

17.05:53 Approach R/T: 'KLM4805, you are cleared to the papa beacon, climb to and maintain flight level nine zero. Right turn after take-off, proceed with heading zero four zero until intercepting the three three five radial from Las Palmas VOR [VHF omnidirectional range radio beacon].' Towards the end of this transmission, and before the controller had finished speaking, the KLM captain accepted this as an unequivocal clearance to take-off and said, 'Yes'. He opened up the thrust levers slightly with the aircraft held on the brakes and •*" paused till the engines stabilised.

17.06:09 KLM F/O R/T: 'Ah, roger sir, we're cleared to the papa beacon, flight level nine zero…’

As the first officer spoke the captain released the brakes at 17.06:11 and, one second later, said, 'Let's go, check thrust'. The throttles were opened to take-off power and the engines were heard to spin up. The commencement of the take-off in the middle of reading back the clearance caught the first officer off balance and during the moments which followed this, he 'became noticeably hurried and less clear'.

KLM F/O R/T: '. . . right turn out, zero four zero, until intercepting the three two five. We are now at take-off.'

The last sentence was far from distinct. Did he say 'We are now uh, takin' off? Whatever was said the rapid statement was sufficiently ambiguous to cause concern and both the approach controller and the Pan Am first officer replied imultaneously.

17.06;18 Approach R/T: ‘OK…’

In the one-second gap in the controllers' transmission, Pan Am called to make their position clear. The two spoke over the top of each other.

17.06;19 Approach R/T: '…stand-by for take-off, I will call you.'

 Pan Am F/O R/T: 'No, uh . . . and we are still taxying down the runway, the Clipper 1736.'

The combined transmissions were heard as a loud three-second squeal on the KLM flight deck causing distortion to the messages. Had the words been clearer the KLM crew might have realised their predicament but, only moments later, a second chance carne for them to assess the danger. The controller had received only the Clipper call sign with any clarity but immediately called back in acknowledgement.

17.06:20 Approach R/T: 'Roger, papa alpha 1736, report the runway clear.'

On this one and only radio call the controller, for no apparent reason, used the call sign papa alpha instead of Clipper.

17.06:30 Clipper R/T: 'OK we'll report when we're clear.'

Approach R/T: Thank you.'

In spite of these transmissions the KLM Boeing 747 continued to accelerate down the runway. The words were lost to the pilots concentrating on the take-off but they caught the flight engineer's attention. He tentatively inquired of the situation.

KLM F/E: Is he not clear, then?'

KLM Capí: 'What did you say?'

KLM F/E: 'Is he not clear, that Pan American?'

KLM Capí: 'Oh, yes.'

The co-pilot also answered simultaneously in the affirmative and the flight engineer did not press the matter. The KLM aircraft continued on its take-off run into the path of Pan Am.

It is difficult for most people to understand how anyone as experienced as the Dutch captain could have made an error of such magnitude. For those used to regular hours and familiar surroundings, with nights asleep in their own time zone ''and frequent rest periods, it may be impossible to comprehend. But the flying environment, although for the most part routine, can place great strain on an individual. Constant travelling in alien environments, long duty days, flights through the night and irregular rest patterns can all take their toll. The Dutch crew had been on duty for almost 9^!/2 hours and still had to face the problems of the transit in Las Palmas and the return to Amsterdam . Lack of recent route experience for the captain, especially in these trying conditions, did not help. The pressure was on to leave Los Rodeos as early as possible and the weather was not making it any easier. A gap in the drifting cloud had presented itself and the captain had taken the opportunity to depart. Close concentration was required on the take-off as clouds were once again reducing visibility. At such moments the thought process of the brain can reach saturation point and can become overloaded. The 'filtering effect' takes over and all but urgent messages, or only important details of the task in hand, are screened from the mind. Radio Communications, which were being conducted by the first officer, were obviously placed in a low priority in the minds of both the pilots once the take-off had been commenced. The controller's use of papa alpha instead of Clipper — the only occasion that day on which this identification was used — reduced the chances of registering the transmission.

On the Clipper flight deck the crew were sufficiently alarmed by the ambiguity of the situation to comment although they were not as yet aware that the KLM had started his take-off run.

Pan Am Capt: 'Let's get the hell out of here.'

Pan Am F/O: 'Yeh, he's anxious, isn't he.'

Pan Am F/E: 'Yeh, after he held us up for an hour and a half . . . now he's in a rush.'

The flight engineer had no sooner finished speaking when the American captain saw KLM's landing lights appear, coming straight at them through the cloud bank.

Pan Am Capt: 'There he is . . . look at him . . . that . . . that son-of-a-bitch is coming.'

Pan Am F/O: 'Get off! Get off! Get off!'

Captain Grubbs threw the aircraft to the left and opened up the throttles in an attempt to run clear. At about the same time the Dutch first officer, still unaware of Pan Am's presence, called 'Ve one', the go or no-go decisión speed. Four seconds later the Dutch crew spotted the Pan Am 747 trying to scramble clear.

KLM Capt:'Oh…..’

The Dutch captain pulled back hard on the control column in an early attempt to get airborne. The tail struck the ground in the high nose up angle leaving a 20m long streak of metal on the runway surface. In spite of the endeavours of both crews to take avoiding action, however, the collision was inevitable. The KLM 747 managed to become completely airborne about l,300m down the runway, near the Charlie 4 turn-off, but almost immediately slammed into the side of Pan Am. The nosewheel of the Dutch aircraft lifted over the top of Pan Am and the KLM number one engine, on the extreme left, just grazed the side of the American aircraft. The fuselage of the KLM flight skidded over the top of the other but its main landing gear srnashed into Pan Am about the position of Clipper's number three engine. The collision was not excessively violent and many passengers thought a small bomb had exploded. Pan Am's first class upstairs lounge disappeared on impact, as did most of the top of the fuselage, and the tail section broke off. Openings appeared on the left side of the fuselage and some passengers were able to escape by these routes. The Pan Am aircraft had its nose sticking off the edge of the runway and survivors simply jumped down on to the grass. The first class lounge floor had collapsed, but the flight crew, plus the two employees in the jump seats, managed to leap below into what was left of the first class section and make their escape. On the left side the engines were still turning and there was a fire under the wing with explosions taking place.

The main landing gear of the KLM flight sheared off on impact and the aircraft sank back on to the runway about 150m further on. It skidded for another 300m and as it did so the aircraft slid to the right, rotating clockwise through a 90-degree turn before coming to a halt. Immediately an extensive and violent fire erupted engulfing the wreckage.

The controllers in the tower heard the explosions and at first thought a fuel tank had been blown up by an .error, but soon reports of a fire on the airport began to be received. The fire services were alerted and news of the emergency was transmitted to all aircraft. Both 747s on the runway were called in turn without success. The fire trucks had difficulty making their way to the scene of the fire in the misty and congested airport, but eventually the firemen saw the flames through the fog. On closer inspection the KLM aircraft was found completely ablaze. As they tackled the conflagration another fire was seen further down the runway, assumed to be a part of the same aircraft, and the fire trucks were divided. It was then discovered that a second aircraft was involved and, since the KLM flight was already totally irrecoverable, all efforts, for the moment, were concentrated on the Pan Am machine. Airport staff and individuals who happened to be on the premises bravely ran to help the survivors.

When the extent of the disaster became known a full emergency was declared on the island and ambulances and fire fighting teams were summoned from other towns. Local radio broadcast requests for qualified personnel to offer their services. Although the request for help was made with the best of intentions the rush to the airport soon caused a traffic jam, but fortunately not before the survivors were dispatched to hospital. Large numbers of islanders also kindly donated blood.

Of the 396 passengers and crew aboard the Pan Am flight only 70 escaped from the wreckage and nine died later in hospital. 335 were killed. All 248 aboard the KLM aircraft perished. On that Sunday evening of 27 March 1977, 583 people lost their lives, and as if to mock those in fear of flying, the accident happened on the ground. It stands on record as the world's worst disaster in aviation history.

As the survivors were being tended in Santa Cruz , firemen at the airport continued to fight the infernos on the runway. In the end, in spite of the intense blaze, the firefighters managed to save the left side of the Pan Am aircraft and the wing, from which 15,000-20,000kg of fuel were later recovered. It was not until the afternoon of the following day that both fires were completely extinguished.

Below:

The burnt out tail of the KLM 747 at Los Rédeos airport.   Associated Press

The events leading to this tragic accident are, summarized in the report of the International Commitee set up to investígate the causes of the accident on behalf of the Insurances Companies, and Spanish " Subsecretaría de Aviación Civil ", Accident Report, 1978 ( ICAO circular 153-AN/56 ), and the American Airline Pilot's Association (ALPA) Accident Report, 1978.

On 27 March 1977 the collisión of the 747s the at Tenerife resulted in the recommendation of improved radio Communications, especially in the take-off phase. On certains airport charts, following a number of other ground incidents, taxiway directions have been printed to help taxying procedures, especially in reduced visibility. The installation of ground radar at airport of Los Rodeos with a fog risk was recommended and people in the Tower control speaking a good English too.

The report atributed responsability in the following ways:

30 % to the Control Tower ( Spanisg Goverment ) and the remainíng 70 % between the Dutch and American aircrafts, the Dutch company paid more. It was rumoured the the Airtrafic controlers were watching a game of football on Spanish TV and this distracted their attention; needles to say the TV was switched off after the accident.

The most infortunate aspect of this accident was the analysis published in the local and Spanish Press. The analysis did not cover or include a description of the events which directly led to the tragedy. The only way to have done this would have been to have waited to see what was recorded in the Blak  boxes.

As this tragic accident took place at Los Rodeos Airport on the island of Tenerife , it is a very weak argument to associate the accident with an incident in other airport on a different island many hours earlier and even weaker to atribute blame to MPAIAC. Following this line of argument it would be very easy to blame the Dutch and American tourist companies, for having send the tourists to Las Palmas instead of sending them to Lanzarote or any place on the world. It would be just as easy to blame the head of the airport authority in Las Palmas ( who was a military officer ) who should have sent the planes to Lanzarote instead to Tenerife .

This line of arguments is the same as that used to describe the Butterfly Effect, where a butterfly flapping its wings in Tokio, can cause a hurricane in Florida . You will never reach any clear conclusion using this kind of analysis. The truth is that the misunderstanding between the control tower and the two aircraft was a result of the fact that radio contact was taking place between the control tower and two aircraft at the same time and using the same frequencies when they should have been using differents frequencies for each aircraft, " the collision resulted in the reconnendation of improved radio communications especially in the take-off phase ".

xxx

BIBLIOGRAPHY

American Airline Pilot's Association ( ALPA ), Accident Report, 1978.

Spanish " Subsecretaría de Aviación Civil " Accident Report, 1978 ( CAO CIRCULAR AN-/ 56) Madrid .

Air Disasters

Dialogue from the Black Box.

Stanley Stewart, 1986  

*  *  *