Do not be nervous, do not rush, do not interrupt: the story of one tragedy
This week marks the 42nd anniversary of the terrible terrorist attack on the Canary Islands, which resulted in the death of almost 600 people. No, the bombing itself, organized by a fighter from the Canary Islands Independence Movement (the organization does not exist today; the author of this article is resolutely against any form of terrorism ) only injured 8 people. However, a series of subsequent events, including technical failures, insuperable external factors, shortcomings in personnel management, human psychology under stressful conditions and simply gross violations of the rules, has developed into such a tangle of incredible tragic coincidences that deserves the most careful analysis.
So, on a clear afternoon on March 27, 1977, a key local tourist hub, Gran Canaria Airport, located on the island of the same name in the city of Las Palmas, was closed by an explosion at a flower stall and threats of another bomb . The disturbing message was taken aback by aircraft heading to this paradise of the Atlantic Ocean, and for some it left no choice. The seventies are the heyday of the transatlantic and other long-haul transportations on the Boeing 747 aircraft. Having flown into series in 1970, this aircraft remained the most spacious in the world for 37 years, and in those years it was even more perceived as a fantastic example of technical progress. But the infrastructure, designed for such large machines in the world was still a little. With the closure of Gran Canaria in the archipelago, there was only one suitable airport for such monsters - Los Rodeos on the nearby island of Tenerife.
One of these aircraft, for which there was no choice, was the Boeing 747 flight 4805 of the Dutch airline KLM. The 50-year-old crew commander, Jacob van Zanten, was an outstanding pilot - 26 years working for KLM, nearly 12,000 length of service, of which more than 1,500 on the Boeing 747. He became literally the face of the airline, with his photos printed advertising leaflets. For the past six months, he served as a flight instructor for the company as an experienced pilot. In fact, he was already one foot in the position of top manager, but today this man was sitting at the helm of an Amsterdam-Las Palmas voyage. Next to him - the co-pilot, 42-year-old Klaas Meurs and 48-year-old flight engineer William Schroeder. Following the instructions of the dispatchers, they turned to the island of Tenerife, landed and disembarked the passengers in the building of Los Rodeos airport.
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Captain van zanten
This did not want to do another Boeing 747 - flight 1736 (Los Angeles - New York - Las Palmas) company Pan American. Commander Victor Grubbs, 56, co-pilot, 39-year-old Robert Bragg, and flight engineer 46-year-old George Warns piloted the Clipper Victor name plane. It was an iconic machine that made the very first commercial flight of the 747th: New York-London flight on January 22, 1970. The crew that had already been in the air for a long time and made an intermediate landing did not want to carry out another one, forced, landing. The tanks had enough fuel to circle Las Palmas until Gran Canaria Airport was checked for explosive devices and opened again.
But the dispatcher instructed them to leave for the alternate aerodrome , freeing airspace. Naturally, the only option could not be optimal, and in Los Rodeos there were already several wide-body aircraft in the village, which created difficulties on the ground. At 14:15 flight 1736 landed. The airfield was small - one runway with one parallel located taxiway. And all of it was crammed with a real cork from aircraft - the Boeing 747 of flight 4805 was closest to the threshold of runway 12, behind it were the Boeing 737, Boeing 727 and DC-8; Flight 1736 occupied the last position in the queue. He had no choice but to wait patiently until his way was cleared.
Two employees of the airline took advantage of the hitch, climbing aboard to fly to the neighboring island.
Unusual flow of aircraft in a small airport, which served on that Sunday, only two dispatchers, creates a nervous situation on the ground. Crews are eagerly waiting for Las Palmas Airport to open, to immediately take off and, flying just 100 km, finally deliver passengers to their destination. And this is happening soon - after just 15 minutes of landing flight 1736, at 14:30, the airport of Las Palmas announces its discovery. Airplanes gradually begin to leave the runway and take off. Boeing 747 flight 1736, as already mentioned, was the last in line. And at its beginning there was a delay. The captain of flight 4805 van Zanten, who landed the car already an hour ago, was now tensely waiting for all his passengers to be at the airport and returned on board by buses. He had an important reason for haste - he really wanted to get passengers to Las Palmas as soon as possible, but now not at all for altruistic reasons.
For a very long time, trade unions have been fighting with airlines to rationalize the working day and improve working conditions. And in response, the KLM policy has become tough. If the staff does not want to recycle - fine, he will now be forbidden to recycle. Just leave the board if you don’t fit into the standard shift time so that you don’t dare to appeal more to harsh working conditions and overtime. But then the flight is automatically postponed until the moment when a fresh crew comes on board. And the passengers are released to the ground and settled in hotels, naturally, at the expense of the airline. The conclusion immediately arises between the lines: surely the airline will follow up, due to which crews did it incur such serious penalties?
And now, when Captain Van Zanten requested an extension of the working day at the airline's office, a strict answer came from there: he must fly to Amsterdam before 7:00 pm With any kind of Canary Island and finding passengers in any way, such problems did not worry managers, the flight should have been completed within the regulatory deadlines. Naturally, Captain van Zanten could not come to terms with what was going on - the delays threatened to turn into a crew replacement and a flight postponed for a day, and he could not allow this stupid situation to affect his prestige and career.
Finally, all the passengers were found, one girl guide decided not to return, but finally went down to the ground to see her boyfriend. But then another bad news came: the airport of Gran Canaria again closed at the landing, because there were also aircraft jams. The dispatchers did not allow the airport on Tenerife permission to fly to the city of Las Palmas. Chances to fly to Amsterdam on time slowly melted. Then Van Zanten requested a full refueling of the aircraft, while they were waiting, so as not to lose time later at Gran Canaria airport.
PanAm Boeing 747 behind KLM Boeing 747
Looking at the tankers with hoses surrounding the KLM plane, the captain of flight 1736 Grubbs felt a strong annoyance. All other aircraft have already left the taxiway. Only KLM's large silver 747, surrounded by gasoline tank trucks, was still blocking their way, and the pilots even went to see for themselves when they entered the field and assessed the dimensions — something about ten meters was not enough to disperse safely. The American crew was already in the cockpit for more than 10 hours, and the senseless expectation of an airplane fully ready for departure did not add enthusiasm to them. They should have left the island of Tenerife a long time ago, which in principle could not even sit down at all.
In the meantime, the early evening began, and its unpleasant feature began to manifest itself at Los Rodeos airport - a humid breeze and slight cooling were brought with it . And it was not a light haze creeping over the ground: in fact, on the island of Tenerife jutting high out of the water, low ocean clouds began to creep into the valley where the airport was located.
Clouds covers the runway of Los Rodeos Airport - contemporary photo, photographer Manuel Luis Ramos Garcia
At 16:45, Boeing Flight 4805 finally finished a half-hour refueling and began to maneuver. The dispatcher, due to the fact that the taxiways were busy with airplanes, ordered the KLM 4805 flight to go to the runway 12, fly it all and turn around 180 degrees at the very end. Three minutes later, flight 1736 started the engines and also received instructions to follow the runway to the third exit, then turn off and continue along the lane along the taxiway. Under the guidance of a dispatcher who spoke with a strong Spanish accent, both aircraft sank into the fog that enveloped the runway. The runway axial lighting lamps did not work and the planes drove behind each other slowly, gradually losing sight of the control tower, taxiways and each other. Nevertheless, the KLM flight was moving faster - captain van Zanten was nervous and in a hurry. The dispatcher answered his request to turn on the lighting of the runway that he was not sure that it was possible, but he would clarify.
In the process of taxiing, flight 1736 was completely disoriented. The dispatcher indicated to turn to the third congress, but, unlike the first and fourth, it was not passing (at 45 ° to the runway), but sharply backward with a turn of 135 °. In principle, there was nothing impossible in such a maneuver - after all, flight 4805 had to turn around at the end by all 180 °. But the fog, the lack of lights on the lane, the bewilderment of why it was necessary to go in a zigzag and doubts that the dispatcher, because of the accent, was correctly understood, formed in the cabin of flight 1736 into alarming uncertainty.
Specially having asked the exit number, board 1736 already received a rather clear answer - “Third. One, two, three - the third. But pilots who are not familiar with the airfield, still doubted. The third in a row, starting from where - from the next turn? Or is the congress, from which they taxied out on the runway, to be considered first? And the dispatcher with a partner, sitting on a tower, generally lost sight of both aircraft in thick fog. At the airport, there was also no surveillance radar to track the movement of aircraft on the ground.
At 17:02, while the flight 1736 was crawling along the lane at a pedestrian speed of about 5 km / h, the dispatcher asked on the radio: “KLM 4805, how many congresses have you already passed?”, To which captain van Zanten replied: “I think just passed the fourth congress. ” Visibility deteriorated, and for the KLM crew there was a threat that it would fall below the limit. Then the airport of Los Rodeos will cease to give permission to take off and about any flight to Amsterdam before 19:00 is out of the question.
The dispatcher said on the radio: "Flight 1736, report back when you clear the lane." The co-pilot Bragg, still looking out for congress number 3, said briefly: "1736."
Van Zanten, meanwhile, reached the edge of the runway and began turning the plane 180 degrees. The dispatcher said: “KLM 4805, report back when you are ready to take off,” to which van Zanten, concentrating on the execution of the maneuver, also answered shortly and not according to the rules: “OK.”
Meanwhile, there were no reports from the PanAm 1736 crew that they had found the third congress, but in fact it was already left behind . At about the same time, van Zanten again asked whether the runway center line lighting lamps were available, and the dispatcher received a negative response. At this, the captain of the Dutch plane just grunted: "And why am I not surprised."
At 17:05, the KLM 4805 flight fully turned around at the end of the runway.
Two huge planes were now turned face to face, separated by hundreds of meters of impenetrable fog.
Captain van Zanten translates the engines' levers to small gas, to which co-pilot Meurs notes with concern: “Wait! We have not yet received permission to fly the tower. " Van Zanten impatiently said: “I know. Come on, ask! ”
AThelerance , or permission to take off on a route, is coordination with the controller of the aircraft’s course after take-off and the transfer of the aircraft to another controller, but it is not permission to take-off. The latter must be received separately.
Meurs sent a request to the dispatcher. He replied: “KLM 4805, after take-off, occupy echelon 90. Turn right onto course 040. After passing the Las Palmas beacon, contact the dispatcher ...”
Meurs repeated the instructions word for word, adding at the end not very clearly: "We, uh ... are going to take off . "
In the headphones of the crew of KLM I heard the voice of the controller “OK ...” and a four-second crash.
Radio communications in aviation are designed in such a way that, having tuned in on the frequency of the dispatcher, any aircraft can hear all the negotiations on this frequency, but can only speak while holding the tangetka, and only when nobody speaks at this frequency anymore. This is called a half-duplex communication - the radio station works only on reception or transmission. You can start talking from your side only by listening to the end of someone else’s message. This is done so that the dispatcher calls and listens to each aircraft separately.
When the co-pilot of flight 4805 KLM announced that their board was going to take off, the dispatcher said: “OK”, and the next moment, in order to be understood correctly, he again pressed the trigger and said: “Be ready for takeoff, I’ll call you”. At the same time, the co-pilot of flight 1736 PanAm Bragg heard that KLM was about to take off and hit his tanetka, shouting: “No! Um ... we are still moving along the lane, 1736! ”
The first button was pressed at 17: 06: 20.08 .
The second is at 17: 06: 20.30 .
Any of the messages was enough for Captain van Zanten to understand: either no takeoff permission has yet been received, or that exactly the same 747 is on the lane ahead. But the receiver mixed two incoming signals at the same time, and both of them turned into headphone flight 4805 into heterodyne noise.
And captain van Zanten, on the short “OK” of the dispatcher, having decided that the formalities of the radio traffic were observed , gave the full power of the engines. Flight KLM 4805 began overclocking.
However, the dispatcher heard the message with PanAm. He responded to Bragg’s concerned request: “Understood you, 1736, report back when you free the lane.” Bragg replied: "OK, we will report when we release." The crew of flight 1736 at this moment just drove to the fourth congress. None of them knew that Boeing KLM had already begun overclocking. But the captain of PanAm Grubbs, as if anticipating something bad, was taxiing to the fourth congress, said: “Let's get the hell out of here!”
Meanwhile, the KLM 4805 flight engineer, having heard the PanAm radio communication with the controller, exclaimed: “Is he still on the runway?”. “What?” Responded van Zanten, barely holding the plane along the runway in the fog. “This PanAm - has it already left the band?” Repeated the flight engineer, to which van Zanten cut off: “Yes!”
Captain Grubbs saw the lights of Boeing KLM on the right in the fog and exclaimed: “Damn, this son of a bitch is coming straight at us!”. Co-pilot Bragg shouted, "Let's go!" Get out! We're leaving! ”, And the pilots gave the engine full power, moving the plane from the lane to the left.
Captain Van Zanten, who had already begun to lift the car through the gaps in the fog, saw the PanAm plane and desperately pulled the steering wheel towards himself. But the heavy aircraft did not immediately leave the ground, striking the tail section of the concrete runway and drawing twenty meters on it, striking a sheaf of sparks.
Boeing KLM nevertheless took off, and his battered nose managed to fly over the fuselage of flight 1736, but the four main landing gear and the leftmost engine at a speed of 300 km / h cut off the first-class cabin and the top of the Boeing PanAm fuselage along the entire length. Its tail section and cabin crashed off. Fuel from the torn-off engine and the ruined KLM tanks rushed from above onto the PanAm and instantly ignited. The 4805, which lost its left-wing engines, flew over two hulls and collapsed on the runway, along which it pulled about another three hundred meters. Fully engulfed in flames, he turned across the strip at the ill-fated third congress, turning into a crematorium for all 248 people on board.
The firefighters arriving at the crash site first begin to extinguish the wreckage of KLM, unaware that two planes were involved in the crash. But through the faults in the hull and along the intact left wing of flight 1736, 70 people can be saved, 61 of whom will survive.
Burning Flight 1736 Boeing few minutes after the crash
Flight wreck 4805
General plan of the disaster site. In the center - the wreckage of the Boeing KLM 4805, soaring from left to right on the photo, in the background - the wreckage of the Boeing PanAm 1736, moving towards. In the foreground is the taxiway, on the left is the third exit from the runway.
The official investigation of the disaster caused an extensive discussion, but stopped as a result of the fault of the Dutch commander - Captain van Zanten went off without the actual permission of the dispatcher. However, in this story it is interesting to disassemble all the intricacies of the factors that led to it.
First of all, it is impossible to unequivocally call a catastrophe at the airport of Tenerife “a chain of tragic accidents”. All the factors leading to it in the text of the article are highlighted in bold, and unequivocally chronological in this catastrophe are only the terrorist attack, the accumulation of aircraft, which caused a delay of both sides on the ground, and then fog, which led to the actual blinding of all participants in the maneuvers, including the dispatcher. The remaining factors would be more appropriate to consider in the framework of the theory of "cheese holes".
The theory of Swiss cheese (or the holes in it is not important, the essence is still well conveyed by the name) likens the reliability of the system to several slices of cheese. The slices themselves are the layers of protection, the fault tolerance levels of the system under consideration.However, each such security system has a built-in or vulnerability that has arisen over time - a hole in the cheese. And if several such holes appear in one place, or become very large and overlap, then an external factor will penetrate under these layers of “armor”, causing a system failure.
Swiss Cheese Model, Il. - Wikipedia
In the history of such “holes” in question, a great many arose because of the sudden influx of many aircraft into one airport. And some "expanded", manifesting where no one was waiting for them. For example, the congestion of airplanes paralyzes the work of the airport and puts pressure on the work of dispatchers, but is not in itself dangerous for cars on the ground. Everything could have done if the queue of the planes took off, using only the taxiway for maneuvers, but the taxiing of two aircraft at once on the existing runway had already expanded the “cheese hole”.
But after all, in clear Canarian weather, two planes would see each other maneuvers all the time. With the arrival of fog, everything would still be fine, work at the airport ground surveillance radar. It would allow to observe the relative position of the aircraft and prevent a collision. But this big “cheese hole” was already at the airport before the crash. Even the delay of flight 1736 on the runway could not play a role - but the incredible timing of the two critical radio messages led to their imposition on the air, and the half-duplex technology of alternate messages did not help. And even this was not the final “slice” that was passed - the last role was played by the extra 50 tons of fuel onboard KLM, because it was because of them that the crew could not tear the car off the runway, desperately lifting the nose of the plane in a cloud of sparks.
Another complex factor was the negligence of radio communication. Informal words and the focus of the controller accompanied all negotiations with both sides. In response to the ATC clearance request, the dispatcher called the van Zanten's sideboard "KLM 4705", apparently due to fatigue and load, confusing the second numbers of the sideboards 4805 and 1736 is insignificant, but still a reservation. A minute later, in response to an alarmed message in 1736, “We are still on the runway!” The dispatcher addressed him “Papa Alfa 1736” (spelled flight number, PA) for the first time in the entire radio exchange. Speculatively, such an appeal could knock the perception of a flight number by ear, as if it were addressed to some other aircraft.
Yes, these specific little things did not affect the development of events. But in the global sense, it was the verbal trifle that led to the catastrophe. After it, short “replies” like “OK” or “Roger” (“Accepted”) became unacceptable without repeating the message from the dispatcher - each air traffic participant became obliged to say on the air what he heard or what he just agreed with. Separately, the concepts of “take off” and “departure” (“departure”) were separated: now the departure route agreed with the dispatcher cannot be confused with the permission to take off. And on that day, between life and death, there was only a short “OK” dispatcher, said in response to an uncertain “we are going to take off” of the co-pilot KLM. And these two letters became the trigger for van Zanten, who impatiently fired with the words "we take off."
This moment is also worth considering in more detail. Here it is impossible to manage with the banal words “even very experienced people make mistakes.” Of course, you can blame van Zanten and his desire to outrun the deteriorating weather. But why did an experienced pilot behave this way? After all, experience is including the ability to prioritize work, and a person in such a responsible position could not not be able to. On this subject, alas, it remains only to make assumptions. Of course, the first step comes the most logical explanation of what happened. How should a person feel, with a portrait of which there are advertising leaflets full of lofty words about Dutch craftsmanship, dedication and accuracy, comparable to a clockwork? Forced to make an unnecessary landing, which is delayed by passengers, refueling, which is pressed by its own company,telling common truths? Stupid trade unions drove him into the framework of formalities, stupid weather changes for half an hour, stupid separatists spoiled his easy and ordinary flight. Of course, this puts pressure on emotions, spoils the mood. But is this enough for critical deviations in the behavior of the commander?
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It may be so, if, just as the dispatcher's short, indefinite reply was heard, his hand on the levers impatiently gave full speed. But something was wrong before this: van Zanten gave a small gas immediately after the turn, disturbing his co-pilot. Did he forget about ATC clearance? And then forgot about a separate permission to take off? Speculation is added by the fact that van Zanten worked for six months at KLM as a flight instructor before this flight. His work included the training of newcomers to all the basics of negotiations with the dispatcher. Could he, speaking the roles of air traffic controllers, unwittingly project this experience? To make a mistake, having routinely spoken all the standard phrases in your head, and not to notice that you gave permission to take off for yourself?
This is speculation, although not implausible. But there is another point. Next to van Zanten were the rest of the crew. Whether the commander forgot or rudely violated the rules - but the co-pilot pulled him up, saying: “Wait! We did not request ATC clearance! ” What went wrong?
Captain's phrase “I know. Come on, request! ”We know from the dry decryption of the black box. It is practically useless without facial expression, intonation, emotions. But what did the co-pilot see in the cockpit - a tired, irritated colleague or the authority of a commander who did not want to contradict? When the captain of the dispatcher’s instructions for the dispatcher’s captain interrupted him with the words “we take off,” he barely heard the repetition of the dispatcher, he did not object a second time to something like “stand, but now you need a separate permission to take off!”. Perhaps the first and second sentences were uttered with undisguised irritation? Or did the pilot feel that the commander was annoyed by his mistake with ATC clearance, and when van Zanten missed and asked for permission to take off, did not he annoy him even more? The situation does not look such a speculation, if we considerthat the co-pilot's flight on the Boeing 747 was only 95 hours against more than 1,500 from the commander, and the license for this type of aircraft was issued to him ... personally Jacob van Zanten, who, as already mentioned, worked as a flight instructor for the airline for six months.
However, the crew’s concern with what was happening took place, because then there was the question of the flight engineer, whether flight 1736 left the band. And here already sounded the full confidence of Captain van Zanten in what is happening. The Dutch word "jawel", sounded in the cockpit, has the meaning not just "yes", but sure, reasoned "yes, exactly" or "so sure . " Was it blind confidence in their actions, haste and irritation, or a manifestation of authority and submission to it? It is difficult to answer this question, but human psychology clearly played a huge role in why the commander of flight 4805, without permission to take off, began its deadly dispersal.
I note that the board 1736, which followed it, acted as the exact opposite of board 4805, which also led to disaster in its own way. After all, if they moved faster on the runway or found a third congress, there would be no collision. But the behavior of the crew is fully consistent with the behavior of an individual disoriented person. To acknowledge that they did not see the necessary turn, to notify the dispatcher about this, to ask again for the third or tenth time whether they need this congress, even if it leads back - the crew’s actions were constrained in everything, as if they were not driving the plane, but went with blindfolded. The general uncertainty due to the limited visibility affected the entire behavior of the crew.
And at the same time, despite the mistakes and violations of the rules, both crews would have a chance to correct the situation in time, if in a lot of the insurers, from the radio to the presence of the radar and direct visibility from the control tower, there were no big holes that coincided.
Robin van Lanskot, the girl guide, by the way, also violated the rules of air transportation, leaving the board of flight 4805 to Tenerife. But thanks to this violation, she is the only one that survived flight 4805.
So, on a clear afternoon on March 27, 1977, a key local tourist hub, Gran Canaria Airport, located on the island of the same name in the city of Las Palmas, was closed by an explosion at a flower stall and threats of another bomb . The disturbing message was taken aback by aircraft heading to this paradise of the Atlantic Ocean, and for some it left no choice. The seventies are the heyday of the transatlantic and other long-haul transportations on the Boeing 747 aircraft. Having flown into series in 1970, this aircraft remained the most spacious in the world for 37 years, and in those years it was even more perceived as a fantastic example of technical progress. But the infrastructure, designed for such large machines in the world was still a little. With the closure of Gran Canaria in the archipelago, there was only one suitable airport for such monsters - Los Rodeos on the nearby island of Tenerife.
One of these aircraft, for which there was no choice, was the Boeing 747 flight 4805 of the Dutch airline KLM. The 50-year-old crew commander, Jacob van Zanten, was an outstanding pilot - 26 years working for KLM, nearly 12,000 length of service, of which more than 1,500 on the Boeing 747. He became literally the face of the airline, with his photos printed advertising leaflets. For the past six months, he served as a flight instructor for the company as an experienced pilot. In fact, he was already one foot in the position of top manager, but today this man was sitting at the helm of an Amsterdam-Las Palmas voyage. Next to him - the co-pilot, 42-year-old Klaas Meurs and 48-year-old flight engineer William Schroeder. Following the instructions of the dispatchers, they turned to the island of Tenerife, landed and disembarked the passengers in the building of Los Rodeos airport.
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Captain van zanten
This did not want to do another Boeing 747 - flight 1736 (Los Angeles - New York - Las Palmas) company Pan American. Commander Victor Grubbs, 56, co-pilot, 39-year-old Robert Bragg, and flight engineer 46-year-old George Warns piloted the Clipper Victor name plane. It was an iconic machine that made the very first commercial flight of the 747th: New York-London flight on January 22, 1970. The crew that had already been in the air for a long time and made an intermediate landing did not want to carry out another one, forced, landing. The tanks had enough fuel to circle Las Palmas until Gran Canaria Airport was checked for explosive devices and opened again.
But the dispatcher instructed them to leave for the alternate aerodrome , freeing airspace. Naturally, the only option could not be optimal, and in Los Rodeos there were already several wide-body aircraft in the village, which created difficulties on the ground. At 14:15 flight 1736 landed. The airfield was small - one runway with one parallel located taxiway. And all of it was crammed with a real cork from aircraft - the Boeing 747 of flight 4805 was closest to the threshold of runway 12, behind it were the Boeing 737, Boeing 727 and DC-8; Flight 1736 occupied the last position in the queue. He had no choice but to wait patiently until his way was cleared.
Two employees of the airline took advantage of the hitch, climbing aboard to fly to the neighboring island.
Unusual flow of aircraft in a small airport, which served on that Sunday, only two dispatchers, creates a nervous situation on the ground. Crews are eagerly waiting for Las Palmas Airport to open, to immediately take off and, flying just 100 km, finally deliver passengers to their destination. And this is happening soon - after just 15 minutes of landing flight 1736, at 14:30, the airport of Las Palmas announces its discovery. Airplanes gradually begin to leave the runway and take off. Boeing 747 flight 1736, as already mentioned, was the last in line. And at its beginning there was a delay. The captain of flight 4805 van Zanten, who landed the car already an hour ago, was now tensely waiting for all his passengers to be at the airport and returned on board by buses. He had an important reason for haste - he really wanted to get passengers to Las Palmas as soon as possible, but now not at all for altruistic reasons.
For a very long time, trade unions have been fighting with airlines to rationalize the working day and improve working conditions. And in response, the KLM policy has become tough. If the staff does not want to recycle - fine, he will now be forbidden to recycle. Just leave the board if you don’t fit into the standard shift time so that you don’t dare to appeal more to harsh working conditions and overtime. But then the flight is automatically postponed until the moment when a fresh crew comes on board. And the passengers are released to the ground and settled in hotels, naturally, at the expense of the airline. The conclusion immediately arises between the lines: surely the airline will follow up, due to which crews did it incur such serious penalties?
And now, when Captain Van Zanten requested an extension of the working day at the airline's office, a strict answer came from there: he must fly to Amsterdam before 7:00 pm With any kind of Canary Island and finding passengers in any way, such problems did not worry managers, the flight should have been completed within the regulatory deadlines. Naturally, Captain van Zanten could not come to terms with what was going on - the delays threatened to turn into a crew replacement and a flight postponed for a day, and he could not allow this stupid situation to affect his prestige and career.
Finally, all the passengers were found, one girl guide decided not to return, but finally went down to the ground to see her boyfriend. But then another bad news came: the airport of Gran Canaria again closed at the landing, because there were also aircraft jams. The dispatchers did not allow the airport on Tenerife permission to fly to the city of Las Palmas. Chances to fly to Amsterdam on time slowly melted. Then Van Zanten requested a full refueling of the aircraft, while they were waiting, so as not to lose time later at Gran Canaria airport.
PanAm Boeing 747 behind KLM Boeing 747
Looking at the tankers with hoses surrounding the KLM plane, the captain of flight 1736 Grubbs felt a strong annoyance. All other aircraft have already left the taxiway. Only KLM's large silver 747, surrounded by gasoline tank trucks, was still blocking their way, and the pilots even went to see for themselves when they entered the field and assessed the dimensions — something about ten meters was not enough to disperse safely. The American crew was already in the cockpit for more than 10 hours, and the senseless expectation of an airplane fully ready for departure did not add enthusiasm to them. They should have left the island of Tenerife a long time ago, which in principle could not even sit down at all.
In the meantime, the early evening began, and its unpleasant feature began to manifest itself at Los Rodeos airport - a humid breeze and slight cooling were brought with it . And it was not a light haze creeping over the ground: in fact, on the island of Tenerife jutting high out of the water, low ocean clouds began to creep into the valley where the airport was located.
Clouds covers the runway of Los Rodeos Airport - contemporary photo, photographer Manuel Luis Ramos Garcia
At 16:45, Boeing Flight 4805 finally finished a half-hour refueling and began to maneuver. The dispatcher, due to the fact that the taxiways were busy with airplanes, ordered the KLM 4805 flight to go to the runway 12, fly it all and turn around 180 degrees at the very end. Three minutes later, flight 1736 started the engines and also received instructions to follow the runway to the third exit, then turn off and continue along the lane along the taxiway. Under the guidance of a dispatcher who spoke with a strong Spanish accent, both aircraft sank into the fog that enveloped the runway. The runway axial lighting lamps did not work and the planes drove behind each other slowly, gradually losing sight of the control tower, taxiways and each other. Nevertheless, the KLM flight was moving faster - captain van Zanten was nervous and in a hurry. The dispatcher answered his request to turn on the lighting of the runway that he was not sure that it was possible, but he would clarify.
In the process of taxiing, flight 1736 was completely disoriented. The dispatcher indicated to turn to the third congress, but, unlike the first and fourth, it was not passing (at 45 ° to the runway), but sharply backward with a turn of 135 °. In principle, there was nothing impossible in such a maneuver - after all, flight 4805 had to turn around at the end by all 180 °. But the fog, the lack of lights on the lane, the bewilderment of why it was necessary to go in a zigzag and doubts that the dispatcher, because of the accent, was correctly understood, formed in the cabin of flight 1736 into alarming uncertainty.
Specially having asked the exit number, board 1736 already received a rather clear answer - “Third. One, two, three - the third. But pilots who are not familiar with the airfield, still doubted. The third in a row, starting from where - from the next turn? Or is the congress, from which they taxied out on the runway, to be considered first? And the dispatcher with a partner, sitting on a tower, generally lost sight of both aircraft in thick fog. At the airport, there was also no surveillance radar to track the movement of aircraft on the ground.
At 17:02, while the flight 1736 was crawling along the lane at a pedestrian speed of about 5 km / h, the dispatcher asked on the radio: “KLM 4805, how many congresses have you already passed?”, To which captain van Zanten replied: “I think just passed the fourth congress. ” Visibility deteriorated, and for the KLM crew there was a threat that it would fall below the limit. Then the airport of Los Rodeos will cease to give permission to take off and about any flight to Amsterdam before 19:00 is out of the question.
The dispatcher said on the radio: "Flight 1736, report back when you clear the lane." The co-pilot Bragg, still looking out for congress number 3, said briefly: "1736."
Van Zanten, meanwhile, reached the edge of the runway and began turning the plane 180 degrees. The dispatcher said: “KLM 4805, report back when you are ready to take off,” to which van Zanten, concentrating on the execution of the maneuver, also answered shortly and not according to the rules: “OK.”
Meanwhile, there were no reports from the PanAm 1736 crew that they had found the third congress, but in fact it was already left behind . At about the same time, van Zanten again asked whether the runway center line lighting lamps were available, and the dispatcher received a negative response. At this, the captain of the Dutch plane just grunted: "And why am I not surprised."
At 17:05, the KLM 4805 flight fully turned around at the end of the runway.
Two huge planes were now turned face to face, separated by hundreds of meters of impenetrable fog.
Captain van Zanten translates the engines' levers to small gas, to which co-pilot Meurs notes with concern: “Wait! We have not yet received permission to fly the tower. " Van Zanten impatiently said: “I know. Come on, ask! ”
AThelerance , or permission to take off on a route, is coordination with the controller of the aircraft’s course after take-off and the transfer of the aircraft to another controller, but it is not permission to take-off. The latter must be received separately.
Meurs sent a request to the dispatcher. He replied: “KLM 4805, after take-off, occupy echelon 90. Turn right onto course 040. After passing the Las Palmas beacon, contact the dispatcher ...”
Meurs repeated the instructions word for word, adding at the end not very clearly: "We, uh ... are going to take off . "
In the headphones of the crew of KLM I heard the voice of the controller “OK ...” and a four-second crash.
Radio communications in aviation are designed in such a way that, having tuned in on the frequency of the dispatcher, any aircraft can hear all the negotiations on this frequency, but can only speak while holding the tangetka, and only when nobody speaks at this frequency anymore. This is called a half-duplex communication - the radio station works only on reception or transmission. You can start talking from your side only by listening to the end of someone else’s message. This is done so that the dispatcher calls and listens to each aircraft separately.
When the co-pilot of flight 4805 KLM announced that their board was going to take off, the dispatcher said: “OK”, and the next moment, in order to be understood correctly, he again pressed the trigger and said: “Be ready for takeoff, I’ll call you”. At the same time, the co-pilot of flight 1736 PanAm Bragg heard that KLM was about to take off and hit his tanetka, shouting: “No! Um ... we are still moving along the lane, 1736! ”
The first button was pressed at 17: 06: 20.08 .
The second is at 17: 06: 20.30 .
Any of the messages was enough for Captain van Zanten to understand: either no takeoff permission has yet been received, or that exactly the same 747 is on the lane ahead. But the receiver mixed two incoming signals at the same time, and both of them turned into headphone flight 4805 into heterodyne noise.
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And captain van Zanten, on the short “OK” of the dispatcher, having decided that the formalities of the radio traffic were observed , gave the full power of the engines. Flight KLM 4805 began overclocking.
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However, the dispatcher heard the message with PanAm. He responded to Bragg’s concerned request: “Understood you, 1736, report back when you free the lane.” Bragg replied: "OK, we will report when we release." The crew of flight 1736 at this moment just drove to the fourth congress. None of them knew that Boeing KLM had already begun overclocking. But the captain of PanAm Grubbs, as if anticipating something bad, was taxiing to the fourth congress, said: “Let's get the hell out of here!”
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Meanwhile, the KLM 4805 flight engineer, having heard the PanAm radio communication with the controller, exclaimed: “Is he still on the runway?”. “What?” Responded van Zanten, barely holding the plane along the runway in the fog. “This PanAm - has it already left the band?” Repeated the flight engineer, to which van Zanten cut off: “Yes!”
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Captain Grubbs saw the lights of Boeing KLM on the right in the fog and exclaimed: “Damn, this son of a bitch is coming straight at us!”. Co-pilot Bragg shouted, "Let's go!" Get out! We're leaving! ”, And the pilots gave the engine full power, moving the plane from the lane to the left.
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Captain Van Zanten, who had already begun to lift the car through the gaps in the fog, saw the PanAm plane and desperately pulled the steering wheel towards himself. But the heavy aircraft did not immediately leave the ground, striking the tail section of the concrete runway and drawing twenty meters on it, striking a sheaf of sparks.
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Boeing KLM nevertheless took off, and his battered nose managed to fly over the fuselage of flight 1736, but the four main landing gear and the leftmost engine at a speed of 300 km / h cut off the first-class cabin and the top of the Boeing PanAm fuselage along the entire length. Its tail section and cabin crashed off. Fuel from the torn-off engine and the ruined KLM tanks rushed from above onto the PanAm and instantly ignited. The 4805, which lost its left-wing engines, flew over two hulls and collapsed on the runway, along which it pulled about another three hundred meters. Fully engulfed in flames, he turned across the strip at the ill-fated third congress, turning into a crematorium for all 248 people on board.
The firefighters arriving at the crash site first begin to extinguish the wreckage of KLM, unaware that two planes were involved in the crash. But through the faults in the hull and along the intact left wing of flight 1736, 70 people can be saved, 61 of whom will survive.
Burning Flight 1736 Boeing few minutes after the crash
Flight wreck 4805
General plan of the disaster site. In the center - the wreckage of the Boeing KLM 4805, soaring from left to right on the photo, in the background - the wreckage of the Boeing PanAm 1736, moving towards. In the foreground is the taxiway, on the left is the third exit from the runway.
The official investigation of the disaster caused an extensive discussion, but stopped as a result of the fault of the Dutch commander - Captain van Zanten went off without the actual permission of the dispatcher. However, in this story it is interesting to disassemble all the intricacies of the factors that led to it.
First of all, it is impossible to unequivocally call a catastrophe at the airport of Tenerife “a chain of tragic accidents”. All the factors leading to it in the text of the article are highlighted in bold, and unequivocally chronological in this catastrophe are only the terrorist attack, the accumulation of aircraft, which caused a delay of both sides on the ground, and then fog, which led to the actual blinding of all participants in the maneuvers, including the dispatcher. The remaining factors would be more appropriate to consider in the framework of the theory of "cheese holes".
The theory of Swiss cheese (or the holes in it is not important, the essence is still well conveyed by the name) likens the reliability of the system to several slices of cheese. The slices themselves are the layers of protection, the fault tolerance levels of the system under consideration.However, each such security system has a built-in or vulnerability that has arisen over time - a hole in the cheese. And if several such holes appear in one place, or become very large and overlap, then an external factor will penetrate under these layers of “armor”, causing a system failure.
Swiss Cheese Model, Il. - Wikipedia
In the history of such “holes” in question, a great many arose because of the sudden influx of many aircraft into one airport. And some "expanded", manifesting where no one was waiting for them. For example, the congestion of airplanes paralyzes the work of the airport and puts pressure on the work of dispatchers, but is not in itself dangerous for cars on the ground. Everything could have done if the queue of the planes took off, using only the taxiway for maneuvers, but the taxiing of two aircraft at once on the existing runway had already expanded the “cheese hole”.
But after all, in clear Canarian weather, two planes would see each other maneuvers all the time. With the arrival of fog, everything would still be fine, work at the airport ground surveillance radar. It would allow to observe the relative position of the aircraft and prevent a collision. But this big “cheese hole” was already at the airport before the crash. Even the delay of flight 1736 on the runway could not play a role - but the incredible timing of the two critical radio messages led to their imposition on the air, and the half-duplex technology of alternate messages did not help. And even this was not the final “slice” that was passed - the last role was played by the extra 50 tons of fuel onboard KLM, because it was because of them that the crew could not tear the car off the runway, desperately lifting the nose of the plane in a cloud of sparks.
Another complex factor was the negligence of radio communication. Informal words and the focus of the controller accompanied all negotiations with both sides. In response to the ATC clearance request, the dispatcher called the van Zanten's sideboard "KLM 4705", apparently due to fatigue and load, confusing the second numbers of the sideboards 4805 and 1736 is insignificant, but still a reservation. A minute later, in response to an alarmed message in 1736, “We are still on the runway!” The dispatcher addressed him “Papa Alfa 1736” (spelled flight number, PA) for the first time in the entire radio exchange. Speculatively, such an appeal could knock the perception of a flight number by ear, as if it were addressed to some other aircraft.
Yes, these specific little things did not affect the development of events. But in the global sense, it was the verbal trifle that led to the catastrophe. After it, short “replies” like “OK” or “Roger” (“Accepted”) became unacceptable without repeating the message from the dispatcher - each air traffic participant became obliged to say on the air what he heard or what he just agreed with. Separately, the concepts of “take off” and “departure” (“departure”) were separated: now the departure route agreed with the dispatcher cannot be confused with the permission to take off. And on that day, between life and death, there was only a short “OK” dispatcher, said in response to an uncertain “we are going to take off” of the co-pilot KLM. And these two letters became the trigger for van Zanten, who impatiently fired with the words "we take off."
This moment is also worth considering in more detail. Here it is impossible to manage with the banal words “even very experienced people make mistakes.” Of course, you can blame van Zanten and his desire to outrun the deteriorating weather. But why did an experienced pilot behave this way? After all, experience is including the ability to prioritize work, and a person in such a responsible position could not not be able to. On this subject, alas, it remains only to make assumptions. Of course, the first step comes the most logical explanation of what happened. How should a person feel, with a portrait of which there are advertising leaflets full of lofty words about Dutch craftsmanship, dedication and accuracy, comparable to a clockwork? Forced to make an unnecessary landing, which is delayed by passengers, refueling, which is pressed by its own company,telling common truths? Stupid trade unions drove him into the framework of formalities, stupid weather changes for half an hour, stupid separatists spoiled his easy and ordinary flight. Of course, this puts pressure on emotions, spoils the mood. But is this enough for critical deviations in the behavior of the commander?
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It may be so, if, just as the dispatcher's short, indefinite reply was heard, his hand on the levers impatiently gave full speed. But something was wrong before this: van Zanten gave a small gas immediately after the turn, disturbing his co-pilot. Did he forget about ATC clearance? And then forgot about a separate permission to take off? Speculation is added by the fact that van Zanten worked for six months at KLM as a flight instructor before this flight. His work included the training of newcomers to all the basics of negotiations with the dispatcher. Could he, speaking the roles of air traffic controllers, unwittingly project this experience? To make a mistake, having routinely spoken all the standard phrases in your head, and not to notice that you gave permission to take off for yourself?
This is speculation, although not implausible. But there is another point. Next to van Zanten were the rest of the crew. Whether the commander forgot or rudely violated the rules - but the co-pilot pulled him up, saying: “Wait! We did not request ATC clearance! ” What went wrong?
Captain's phrase “I know. Come on, request! ”We know from the dry decryption of the black box. It is practically useless without facial expression, intonation, emotions. But what did the co-pilot see in the cockpit - a tired, irritated colleague or the authority of a commander who did not want to contradict? When the captain of the dispatcher’s instructions for the dispatcher’s captain interrupted him with the words “we take off,” he barely heard the repetition of the dispatcher, he did not object a second time to something like “stand, but now you need a separate permission to take off!”. Perhaps the first and second sentences were uttered with undisguised irritation? Or did the pilot feel that the commander was annoyed by his mistake with ATC clearance, and when van Zanten missed and asked for permission to take off, did not he annoy him even more? The situation does not look such a speculation, if we considerthat the co-pilot's flight on the Boeing 747 was only 95 hours against more than 1,500 from the commander, and the license for this type of aircraft was issued to him ... personally Jacob van Zanten, who, as already mentioned, worked as a flight instructor for the airline for six months.
However, the crew’s concern with what was happening took place, because then there was the question of the flight engineer, whether flight 1736 left the band. And here already sounded the full confidence of Captain van Zanten in what is happening. The Dutch word "jawel", sounded in the cockpit, has the meaning not just "yes", but sure, reasoned "yes, exactly" or "so sure . " Was it blind confidence in their actions, haste and irritation, or a manifestation of authority and submission to it? It is difficult to answer this question, but human psychology clearly played a huge role in why the commander of flight 4805, without permission to take off, began its deadly dispersal.
I note that the board 1736, which followed it, acted as the exact opposite of board 4805, which also led to disaster in its own way. After all, if they moved faster on the runway or found a third congress, there would be no collision. But the behavior of the crew is fully consistent with the behavior of an individual disoriented person. To acknowledge that they did not see the necessary turn, to notify the dispatcher about this, to ask again for the third or tenth time whether they need this congress, even if it leads back - the crew’s actions were constrained in everything, as if they were not driving the plane, but went with blindfolded. The general uncertainty due to the limited visibility affected the entire behavior of the crew.
And at the same time, despite the mistakes and violations of the rules, both crews would have a chance to correct the situation in time, if in a lot of the insurers, from the radio to the presence of the radar and direct visibility from the control tower, there were no big holes that coincided.
Robin van Lanskot, the girl guide, by the way, also violated the rules of air transportation, leaving the board of flight 4805 to Tenerife. But thanks to this violation, she is the only one that survived flight 4805.
Source: https://habr.com/ru/post/445136/
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