**If you are familiar with this incident, skip the first paragraph**
**"Air Disasters" by Marriot, Stewart, and Sharpe is credited with the quotes and information presented in this post.**
For those who do not know about this accident, it involved two 747's (Pan-Am & KLM) at Tenerife, Canary Islands in 1977. The KLM 747 had just completed a 180 degree turn and was lined up awaiting takeoff clearance. The Clipper jet was on the runway, facing the KLM 747, although they could not see each other. They were instructed to turn off on the charlie 3 taxiway and then report to Approach control. (the approach freq. was being used for both takeoff and approach) In any case, the KLM started its take-off roll and by the time the two jets saw each other, it was too late. The KLM captain pulled back on the yoke, but the main landing gear struck the Clipper jet at the position of the number three engine,(from left) as it was frantically trying to turn off of the runway. The KLM 747 then "skidded for 1,000 feet and as it did so the aircraft slid to the right, rotating clockwise through a 90 degree turn before coming to a halt." The plane was immediately engulfed in flames, and all occupants were killed. The whole upper portion of the Clipper 747 had been ripped off, and the pilots escaped through a hole in the front of the fuselage. "Of the 396 passengers and crew aboard the Pan Am flight, only 70 escaped from the wreckage and nine later died in the hospital."
**And now on to the cause**
I was always under the impression that the KLM captain was at fault for this accident, but further research on the subject may have changed my mind. Picture this scenario for a moment: The KLM 747 is lined up and ready for take-off. The Pan Am 747 is still on the runway facing KLM, and is searching for Charlie 3 through the confusion of dense fog and heavy atc accents. I'm going to pick it up at KLM's request for take-off clearance:
KLM F/O: "KLM4805 is now ready for takeoff and we are waiting for out ATC clearance"
At this time, the Clipper 747 had inadvertently passed the C3 exit and continued towards the KLM 747.
Approach: "KLM4805, you are cleared to the papa beacon, climb to and maintain flight level nine zero. Right turn after take-off, proceed with heading four zero four until intercepting the three three five radial from Las Palmas"
The KLM captain assumed this to be a take-off clearance by approach control. He opened up the throttles and released the brakes.
KLM F/O: "Ah, roger sir, we're cleared to the papa beacon, flight level nine zero. Right turn out, zero four zero, until intercepting the three two five. We are now at take off."
The final sentence was not understood by the Pan-Am 747 or the ATC officer.
The next two transmissions were almost simultaneous, and the KLM 747 heard neither of them. Only a squeal and unintelligible blurbs were heard in their cockpit.
Approach: "stand by for take-off, I will call you."
Pan Am F/O: "No, uh....and we are still taxying down the runway, the clipper 1736"
Approach: " Roger, papa alpha 1736, report the runway clear"
This was the one and only time that the ATC officer referred to the Pan Am 747 as "papa alpha."
Pan Am 747: "Ok we'll report when we're clear"
Approach: "Thank You"
The KLM F/E expressed some concern, but was quickly brushed off by the captain and F/O.
KLM F/E: " Is he not clear that Pan American?"
KLM captain: "oh, yes"
A few seconds later, the two jets collided. There was obviously a lot of confusion during the minutes before this accident. In MY opinion the three critical errors were:
1.) The failure of the KLM 747 captain to obtain absolutely certain clearance in the low visiblilty.
2.) The ATC officers' failure to immediately re-transmit the following message, "stand by for take off, I will call you." The KLM crew never responded to the message, and the officer should have re-transmitted it right away to be sure they understood.
3.) The lack of directional support (namely signage) to help pilots navigate on the ground in low visibility.
What do you guys think?