- 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
- 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
- SIGHTINGS HOMEPAGE
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