PDA

View Full Version : Anybody else get this on the Continental Crash ??



luckydog
February 25th, 2009, 15:43
> *Subject:* New Twist in Continental Express Flight 3407
>
>
>
>
>
>
>
>
>
>
>
>
>
> Southwest just sent this to their pilots yesterday in
> regard to the approach
> in Buffalo..
>
>
>
>
>
>
>
>
>
>
>
> *"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."*

Curtis P40
February 25th, 2009, 16:26
WOW Wasn't somebody else using Autopilot? Wonder how long they have known about that?

Willy
February 25th, 2009, 16:29
Dang sure makes ya wonder....

GT182
February 25th, 2009, 16:40
With the weather as bad as it was that day, they shouldn't have been using the autopilot... which they did. And from what I've heard from the pilots here, that's what caused the crash.

Now, does approach mode make use of the autopilot? If not, why wasn't AP use mentioned in the warning issued.

deathfromafar
February 25th, 2009, 20:06
Problem is that even if you're hand flying the approach/ILS and the beam(signal) is being deflected/bent by interference being electro-magnetic or Earthen obstruction(s), the needles are going to move giving a false indication. That can easily still land you in a heap of trouble in a heartbeat in that configuration(on approach in max drag config). Most airline crews fly the approach on autopilot/FMS using the STAR anyhow. Once established on localizer they can hit approach hold to center up on the ILS beam. Nearly all aircraft have specific O-L's and warnings in their Flight Manuals that about certain conditions & hazards to avoid throughout the flight envelope range.

Toastmaker
February 26th, 2009, 07:43
Um. . . so get a front-end loader to remove the earthen obstruction and problem solved ??

Railrunner130
February 26th, 2009, 15:39
Interesting twist. Although to me it doesn't make sense.

It seems to me that the FAA SHOULD have found this and had the ILS shut down until it was fixed. Being an "earthen" structure, it had to have been there a while. Unless, perhaps they don't test the ILS in the way mentioned above.

Either way, time will tell.

boz
February 27th, 2009, 13:15
Railrunner130 is right - this dosen't make any sense as there are no "notams" on this runway for that airport other than approach lights which just increases minimums. Story is bogus.

Boz