Oakum_Boy
supercalifragilistic
- Joined
- Nov 10, 2003
- Posts
- 2,405
This could put a whole new slant to what happened.
You bet it could.
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This could put a whole new slant to what happened.
Safety Alert 2009-1
BUF ILS Hazard
Hazard to ILS to runway 23 in BUF
SWAPA Pilots,
There is a potentially significant hazard concerning the ILS to runway 23 in BUF.
Information has been received indicating it is possible to obtain a significant nose pitch up, in some cases as much as 30 degrees, if the glide slope is allowed to capture before established on centerline. Pilots who are preparing to configure and land have the potential to experience abrupt pitch up, slow airspeed, and approach to stall if conditions present themselves in a certain manner.
This effect is the result of an earthen obstruction close enough to the ILS to affect the integrity of the glide slope signal. This has resulted in the issuance of an advisory given on ATIS which states that "the ILS Glide Slope for runway 23 is unusable beyond 5 degrees right of course."
When attempting to intercept the runway 23 ILS from right traffic, the ILS glide slope indication may read full deflection down. Just prior to intercept it may then move up in such as manner as to enable approach mode to capture in such a way as to result in a nose up pitch and loss of airspeed.
Southwest Airlines has issued a notice reading: "Until further notice, when executing the KBUF ILS/LOC Runway 23, DO NOT select Approach Mode until established on the localizer inbound."
This issue is being addressed on several levels in an attempt to address procedures, facilities, and communication regarding this matter. If you experience any issues related to this, please file an ASAP form and or call SWAPA Safety at SWAPA toll free.
This could put a whole new slant to what happened.
They are leaking this out slowly so that when it fully comes out it is not a bomb shell.
FWIW, it could be any of us, and if you think you are above it, you have not been aviation long enough.
Good point, but the problem gets people at both ends and in the middle too.I understand what you meant, but your statement should read:
......and if you think you are above it, you have been in aviation too long already.
In reading the Q drivers explanation of how the AOA/Stall system is rescheduled in icing, the wing may not have actually aerodynamically stalled until it reached it's critical AOA during the abrupt pull-up maneuver.
There may not have actually been an aerodynamic stall when the pusher activated, since the pusher is biased by 20 knots as a function of being in icing conditions.
Put another way, with the 'icing switch' off, stall speed was shown to be computed at 90 kts or so.
. . .
Likely, as is typically the case, a combination. But it is clear the speed was allowed to decay to a very low value. After this, the abrupt pull-up sealed their fate at such a low altitude.
That was my first thought.There are flight directors that will drive to a 30 degree pitch up?!?!?
Yup, from the south. Last assigned hdg was 260 to joinAlso, didn't 3407 intercept from the South, ie. left traffic? I don't remember from the ATC tapes, maybe someone out there can refresh my memory? Thx.
I agree with this scenario.
We'll know perhaps whether the crew was concerned about a tail stall from the CVR. They seemingly reacted to a perceived tail stall: extend flaps, the AP disconnects and they get shaker, then pusher. In a tail stall the nose drops, the remedy is to retract flaps and increase back pressure. Only thing is, they could've misinterpreted it. Stick shaker and pusher means WING STALL.
Fly the plane first, if the plane is still flying, don't mess with it. I got AP disconnect, shaker and pusher once with the boards out when new in the RJ on a visual. I had focused on descending after ALTS CAP to catch the GS, only a lower ALT hadn't been selected. I had increased thrust, but not enough to compensate for the drag from the flight spoilers. It took the jumpseater behind us to say 'spoilers' (yes this was humbling for me) before I clued in. But in that momemt before I got SA back I had increased thrust some, and done nothing to the pitch attitude.
Pilot error is sad, tragic, and unfortunately often a fact of life in aviation accidents. NBC didn't do regional pilots any favors tonight, explaining how long (short really) each had been employed by Colgan.
It is sad that pilot error is even still allowed to be labeled as the direct cause of an accident. It is well established that humans will always err, but our aviation system has evolved to a state of being able to trap most errors. The only way to prevent further accidents is to explore why the system failed to trap the error. This cannot be meaningfully done by simply closing the case with "pilot error" yet again.