from the pen of icarus blake

I love accidents.  I don’t mean that in the morbid “I love the horror of a bunch of people dying,” I assure you.  Instead, I love examining the many clockwork fragments of these events, like the terrible PR approach that blew Threemile Island into a public relations nightmare or the numerous regulatory failures that allowed the OceanGate submersible to proceed with missions until it imploded.  Each accident is a collection of unique factors, many that could have been spotted and remedied with preventative action and many more up to pure random chance, and no incident encapsulates this phenomenon like the Tenerife Airport Disaster on March 27, 1977.

Tenerife North Ciudad de la Laguna Airport, formerly Los Rodeos Airport, is a small airport in the Canary Islands and the site of the single most deadly airline crash ever to occur.  The trouble began in Gran Canaria Airport, when the Canary Islands Independence Movement set off a small bomb inside the terminal and threatened three more explosions to come.  Incoming flights were routed to Los Rodeos Airport, which was quickly overwhelmed with large passenger jets from the larger airport, including two Boeing 747’s: KLM Flight 4805 and Pan Am Flight 1736.

The delay frustrated pilots and passengers alike, but none more than the pilots on KLM Flight 4805.  KLM was a Dutch airline, and a new law for Dutch pilots passed recently restricted the allowable flight hours for pilots operating within Holland.  The pilots were approaching the limit, and the delay threatened to exceed it, leaving them open to corrective action by the airline.

While pilots and passengers fretted about the state of their jobs and their vacations, a quirk of Los Rodeos reared it’s head: a thick bank of fog rolled over the airport, obscuring everything.  Worth noting that, at this time, Los Rodeos had no ground radar system to track planes in low visibility conditions — they could only monitor visually from the tower.  When Pan Am Flight 1736 was sent taxiing down the runway to prepare for takeoff, they failed to see their turn in the fog.  This left them on the runway when the already short-staffed air traffic controllers told KLM Flight 4805 to line up.  In a hurry, and with no standard language to confirm takeoff in 1977, the pilot of KLM Flight 4805 took the air traffic controller’s use of “OK” over the radio to mean “OK for takeoff”, and began.  Though Pan Am 1736 and the air traffic controller protested, both the transmissions came onto the radio at once in a blare of static, and the flight crew of KLM Flight 4805 did not understand.

The pilots of Pan Am 1736 tried desperately to maneuver their 747 out of the way, but a 747 on the ground does not move fast and a 747 preparing for takeoff does.  KLM Flight 4805 collided with Pan Am 1736, shredding the belly of the Dutch plane and taking a chunk out of the back of the American one before smashing against the ground just beyond the runway.  All 248 passengers and crew aboard KLM Flight 4805 died, as did 335 passengers and crew aboard Pan Am 1736.  For the fog, no one could see the wreckage of the Pan Am flight, so emergency crews rushed for the doomed KLM flight instead, leaving the scant survivors to pull the bodies from the wreckage themselves in those first harrowing minutes.

To summarize, these are the factors within control:

1. Tarmac vocabulary and terminology – there’s no distinct takeoff command, allowing the KLM captain to take “OK” as permission for takeoff.
2. Staffing of Air Traffic Control – Los Rodeos ATC had been running on a skeleton crew for a while for budgetary reasons.  Maybe this isn’t the best place to cut costs, hm?
3. New strict flight time laws for Dutch pilots – if the KLM pilots hadn’t been anxious about retribution, they would have been more likely to take their time on the runway.

And these are the factors outside control:

1. The thick fog that rolled in at the worst possible time, causing the Pan Am flight to miss their turn, delaying emergency crews, and preventing the KLM flight from seeing the other plane on the runway.
2. The bombing at the Gran Canaria, that rerouted flights to Los Rodeos and overwhelmed the smaller airport with large aircraft.

In the aftermath, KLM and Dutch authorities reluctantly accepted responsibility for the accident and paid restitution to the survivors.  New vocabulary stipulations were put in place, so that the word “takeoff” could only be spoken when an aircraft is cleared for takeoff and preventing the use of colloquial phrases such as “OK” or “Roger” from ATC.  Aircraft lined up on the tarmac for takeoff are now given the command to “hold position” until they’re cleared.  A second airport was built in Tenerife in 1978 — Tenerife South Airport — which did not have the same fog issue as Los Rodeos, and reducing the risk that comes with low visibility conditions.  Los Rodeos also installed ground radar in the interest of preventing incidents like this in the future.

My heart goes out to all 583 people who died that day, and all of their families.  They should not have had to be lost to improve the safety conditions of the aviation industry, regardless of the conditions outside their control.  I believe that, regardless of the ruling, no single person is at fault for this tragedy.  I am only glad we’ve learned from it.