SIGHTINGS



A Pilots's Analysis
Of The Flight 261 Crash
By John Prukop <ccw@wolfenet.com>
From Newshawk <hawkeye@saber.net>
2-5-2000


In addition to holding an ATP myself and airline experience with the commuters (turboprops with "T"-tail configuration), a close personal friend of mine is a senior check airman and sim instructor at one of the majors. We've discussed the Alaska FLT 261 scenario. A runaway stabilizer or jammed stabilizer is a controllable thing, which is routinely practiced with applicable emergency procedures to handle this type of thing.
 
Understand that FLT 261 was in cruise flight conditions at Flight Level 310 (31,000 feet) as best we can determine. Unless some EXTERNAL force would upset the longitudinal or lateral trim of the aircraft in cruise (which at the time would have been most likely on autopilot with only very minor inputs to the control servos to keep the aircraft level and in trim) -- or an input to the control surfaces from the pilots themselves (unlikely) -- IF for some reason the stab-trim motors activated which turn gears, which in turn change the pitch attitude of the entire "T" tail stabilizer (not the elevator hinged at the aft edge of the stabilizer), and were in what is termed a "runaway stabilizer" condition, the pilots would have immediately gone through an emergency checklist and pulled the CB's (circuit breakers) that control those motors and cutoff and remove electrical power from that system. There is evidence they did do this. Then with normal control inputs via the control wheel, elevator control at the aft edge of the stabilizer would enable them to control the pitch attitude of the aircraft and commence a descent and emergency landing ... THE AIRCRAFT WOULD BE controllable. HOWEVER, it is possible on the DC-9 and MD-80 series with the "T" tail configuration (unlike the B737) to over-correct. That is to say, if the airplane is slowed up too much, so that the long fuselage and nose is shadowing or blocking airflow over the "T" tail, the aircraft COULD snap forward violently, inverted, because of the "T" tail no longer providing a balance of the weight distributed along the fuselage. An example would be a teeter-totter, balanced in the middle, and all of a sudden you remove weight from one end -- the other end snaps violently downward -- but in the air, there is nothing to stop the forward snapping down, and so the airplane goes inverted and into a dive. If this anomaly occurred at 17,000 feet -- as we have been led to believe -- when FLT 261 was cleared for an emergency landing into LAX -- 40 miles away (which makes no sense at all considering the circumstances and the closeness of NAS Point Mugu with its 12,000' runway), the airplane would not have had sufficient altitude to recover from the resulting dive. The scenario would have played out as we have witnessed.
 
Also, the evidence of "popping" sounds as the aircraft was descending leads me to believe the engines, which are mounted below and slightly forward of the tail/stabilizer - which would have also been shadowed by the fuselage when slowing up the airplane too much - could have been compressor stall of the forward blades in the engine intakes, but this is conjecture on my part. The compressors would most likely have stalled in the above scenario.
 
So, what I'm saying here is that, YES, it is possible to land the plane with a jammed or runaway stabilizer and has been done on a number occasions without incident ... but at the same, time if over-correction was induced such that the "T" tail and engines were blocked of airflow in slowing the aircraft too much, the above scenario could play itself out with catastrophic results.
 
Something you need to know here, is that an airplane is slowed by reducing power and applying back-pressure on the control wheel; in addition, forward slats are extended on the MD-80 series increasing the lift of the wings by the increased upper curvature -- and when the airplane is slowed, the pitch attitude changes such that the nose is higher than the tail -- however, you can reach a point in the pitch attitude when slowing that the airplane stalls -- and this event on a "T" tail configured MD-80 series aircraft can be critical.
 
I think it very important to keep in mind that all was well with FLT 261 ... UNTIL it reached the vicinity of Point Mugu, Restricted Area R-2519, and Warning Area W-289. There is evidence to indicate that live firing of surface to air missiles were occurring at the time; but regardless of that, what "if" the military was experimenting with EM or laser enhanced warfare systems? I maintain that something EXTERNAL initialized the series of events leading to the termination and destruction of FLT 261 ... and the pilots were simply attempting to cope with what they thought was a stabilizer problem. The "bangs" heard by the stewardess and flight crew raise suspicion of structural failure of some kind ... we still don't know if there was a sudden decompression of the cabin at altitude - which those kinds of sounds could be attributed to - a failing pressure bulkhead. And it is impossible to tell if some tail components of FLT 261 were missing in the fuzzy picture that's been circulated by the media. Something initialized the series of events ... perhaps part of the tail feathers were blown off ... this would make sense if a missile encounter occurred because the missiles would seek the exhaust heat of the engines mounted directly below the stabilizer tail area.
 
The strangest part of the story as told by NTSB is that there was NO further contact with FLT 261 subsequent to the airplane being cleared to descend from 17,000 feet. They acknowledged the clearance ... and then there was nothing further heard from FLT 261 for about 6 or 7 minutes. They would have at least cried out, "LA Center ... 261 .. we're going down ... can't control the airplane" ... or something in those final minutes. That they did not say anything is indeed STRANGE. Were they incapacitated? How come only 4 bodies recovered? And how do you like the graphic presentation that's been shown by the media of the MD-83 with the Alaska Eskimo, leisurely descending to the water in almost a flat descent? Eye witnesses state the aircraft descended in almost an 80 degree nose down attitude - inverted. The entire NTSB-news media story doesn't jive. By the way, we don't think the crew of FLT 261 was ever contemplating a water-landing or ditching. Most likely they were navigating via J1-7 or J88-126 after passing the LAX VOR, enroute to SFO and went out over the ocean to prepare the airplane for landing back at LAX.
 
Hope this helps.
 
/s/ John R. Prukop/ATP

 
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