CHAOS ON THE RUNWAY

 

It is March 27, 1977. PanAm flight 1736 is on its way to Gran Canaria, Spain, from Los Angeles. There are 380 passengers and 16 crew members and the plane is a Boeing 747, the first ever to enter service. The captain of the flight is Victor Grubbs.

Ahead of flight 1736 there is KLM flight 4805 flying from Amsterdam to Gran Canaria. There are 235 people on board. The captain is Jacob van Zanten.

At 13:15 at the Gran Canaria airport, called Las Palmas, a bomb explodes, injuring one person. Soon after, the airport receives another call threatening for a second bomb. The authorities shut the Las Palmas airport and divert all the flights that had to land there.

The tower informs the two flights about what happened and tell their pilots to divert to Los Rodeos airport in Tenerife. This is a very small airport and has only one runaway, so it can’t easily handle such huge aircrafts.

The two pilots protest saying they have enough fuel to go in circles above Gran Canaria until its airport would open again. But the tower denies the request, not knowing when the airport would be available again. 

The KLM Boeing lands first and PanAm’s right after. In total, there are 5 flights diverted in Los Rodeos. Flights are told to stay in the taxiway, a path used by planes to move from a part of the airport to the other.

The captain of KLM asks the tower to allow its passengers to get off the plane so they won’t get bored. The tower approves and adds that a bus was being sent right in that moment. The PanAm captain asks the same, but since the terminal is full the tower denies. Passengers are, however, allowed to get off the plane and stay near. 

At 14:30 Los Rodeos is informed that Gran Canaria has reopened and the flights are given an “all-clear” to land where they originally had to.

Meanwhile it’s started raining and the visibility is decreased due to the thick fog.

The KLM captain re-gathers his passengers and orders its aircraft to get refuelled. Since the PanAm aircraft was parked behind KLM’s, the first captain asks how long the refuelling is going to take. KLM’s captain answers “35 minutes” and then hangs up on him. The other  PanAm crew members leave the aircraft to see if they can get around the KLM Boeing but there isn’t enough space.

At 4:30pm KLM 747 is fully refuelled and is given clearance to “backtrack” and go and hold position to runaway 30.

Backtracking is a maneuver that involves using the runaway as a taxiway and it’s used when the main runway is blocked by another aircraft, so the other planes have to first taxi down the runway and then do a 180 degrees rotation to take off in the opposite direction.

In the meantime, fog has become so thick that is difficult to see over a distance of a few hundred meters. The fog also prevents the tower from seeing where the two planes are and flight controllers have to rely on what the pilots say.                                                

Then the tower orders PanAm 747 to follow KLM and to get out the runaway using exit number 3. The crew isn’t sure whether the tower has told them to take the 1^st or the 3^rd exit so they ask for clarification. The tower’s reply: “The third one sir. One, two, three. Third, third one”.

Anyway, PanAm crew seems to be unsure of their position on the runway.

Meanwhile, KLM 747 has finished the backtracking maneuver. Right after lining up, without the tower consent, the pilot moves the throttles forward (powers engines and accelerates) and the aircraft starts gaining velocity.  The KLM captain asks the tower for clearance. The instruction given contained the word “take-off” but didn’t include an explicit statement that the flight was cleared for take-off. KLM 747 tells the tower it’s starting taking off.

Few seconds after the towers says: “Ok stand by for take-off, I will call you”. Only “ok” was clearly heard from the crew due to radio interference. In fact, in that exact moment, the PanAm pilot calls the tower to tell them that they are still on the runway. But the tower was talking to the KLM 747,  so the  simultaneous calls caused a loud squeak that didn’t allow the KLM pilot to fully understand the tower’s information.

The tower tells to the PanAm flight to clear the runway and overhearing this, the KLM flight engineer expresses his doubt whether the PanAm Boeing could be still on the runaway. The captain ironically confirms runway’s clear. KLM 747 is now at a point where take-off can’t be aborted and PanAm has just got out from exit C4.

Suddenly, the PanAm crew sees the lights of the KLM 747 approaching them fast. The pilot tries to full power the engines to get off the runaway and take the plane onto some grass alongside the runway.

KLM captain has seen PanAm 747 before him and tries to lift the nose of the plane but he can’t do anything to avoid the collision. KLM flight 4805 slammed into PanAm flight 1736 at a speed of 260 km/h.

No passenger on board the KLM survived while 61 passengers on board the PanAm made it. In total 583 people died, making it the worst disaster in aviation’s history.

Maria, 4scB