I am posting this case study fifty years to the day after Trans International Airlines Flight 863 took off from KJFK with crew only, scheduled to fly to KIAD to pick up passengers on their way to London. A lot has changed in those five decades and most operators and pilots have fully absorbed the lessons from this crash. I worry that some pilots, young and old, might not have witnessed just how dangerous the simply mundane can be. This is a good one to reinforce that no details are too small to consider in aviation.
On the surface of the event is the thought that a bit of asphalt got kicked into the elevator and caused the airplane to rotate early and eventually takeoff in an uncontrolled manner. As the NTSB points out, once the airplane was airborne there was very little the crew could have done. The DC-8 was built with control tabs, much like the balance tabs used in Boeings of the era, in some of the flight controls and the gaps between surfaces may have made it more susceptible to this kind of Foreign Object Damage (FOD). So two things to do, back in 1970. First, design better flight control systems, less susceptible to this kind of thing. Second, do a better job of keeping the areas near airplanes FOD free. Okay, job done. Or is it?
A closer reading of the NTSB report reveals that when the airplane rotated prematurely, the aircraft had only used 1,500 feet of the runway. The airplane then dragged its tail on that runway for nine seconds before lifting off. The mindset back then was about the only thing worthy of a takeoff abort was an engine failure or fire. But picture yourself with the tail dragging on the runway, you are just doing 100 knots, you have most of the runway in front of you, and you don't know why the nose isn't reacting to your full nose down elevator movement on the yoke. Wouldn't that be worth an abort? The report never mentions V1 but part of my "go / no-go" briefing includes "if the airplane will not fly" as a valid reason for an abort above V1. Left unsaid but implied, "if the airplane will not fly under my control."
Here are the lessons as I see them:
Earlier this year I landed at a small Florida airport I had never been to but certainly large enough for my Gulfstream. I was shocked by the condition of the taxiways and ramp and even more disheartened by all the loose gravel. I was fortunate to have three mechanics on board (this was a maintenance proving run) who inspected the airplane from nose to tail and gave us a clean bill of health. The next day we fired up and left. In retrospect, I should have had the airplane towed to someplace devoid of these threats before firing up and leaving. We all make mistakes and this was one of my bigger ones.
This crew did a flight control check during their taxi to the runway but apparently the errant piece of pavement was kicked to their tail after this. The Gulfstream world has adopted a last minute flight control check just prior to taking the runway. At first I thought this was overkill — I did a flight control check after engine start in the chocks, after all — but now I understand the wisdom of this technique.
The NTSB report dances lightly on the subject in this accident. It was the first officer's takeoff and he only commented that he could not control the aircraft after they were airborne. I suspect he realized this well before but deferred to the captain's judgment. I think if the first officer realizes the aircraft will not fly under his or her control, he or she should abort the takeoff and sort out the details later.
Everything here is from the references shown below, with a few comments in an alternate color.
Photo: Elevator control system, NTSB-AAR-71-12. figure 1.
Click photo for a larger image
[NTSB-AAR-71-12, ¶1.7] The accident occurred in bright daylight.
[NTSB-AAR-71-12, ¶2.2(b)] The Board determines that the probable cause of this accident was a loss of pitch control caused by the entrapment of a pointed, asphalt-covered object between the leading edge of the right elevator and the right horizontal spar web access door in the aft part of the stabilizer. The restriction to elevator movement, caused by a highly unusual and unknown condition, was not detected by the crew in time to reject the takeoff successfully. However, an apparent lack of crew responsiveness to a highly unusual emergency situation, coupled with the captain's failure to monitor adequately the takeoff, contributed to the failure to reject the takeoff.
NTSB Aircraft Accident Report, AAR-71-12, Tran International Airlines Corp., Ferry Flight 863, Douglas DC-8-63CF, N486T, J. F. Kennedy International Airport, New York, Sept 8, 1970
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