New twist to Colgan 3407 crash in Buffalo

Posted on 27. Feb, 2009 by in Featured

Below is a safety alert I received from my union today:

Forwarding Safety-Related Information Could Save Lives

Last week, SWAPA�s Safety Committee warned of a potentially dangerous problem involving the ILS 23 at BUF. Although BUF is not currently a destination for our crews, it is an alternate. In an effort to keep you informed, we’re passing on the pertinent information.

When turning to intercept the final approach course, the approach mode was armed. Just outside 5 degrees, the glideslope became erratic and commanded severe pitch changes. They have determined that an earthen mass to the right side of final is causing the anomaly.

You may recall the recent fatal accident involving Colgan Air Flight 3407. The approach in use was ILS 23 at BUF. The DHC-8 Q400 pitched up to 31 degrees just before it crashed. The NTSB and FAA have not determined if the glideslope was a causal factor, but the investigation is still ongoing.

As with most new information, ATIS is now reporting that the glideslope is unusable outside 5 degrees of the final approach course. To our knowledge, this has not made it into the NOTAM system yet. We highly recommend that you DO NOT select approach mode until you�re established on the localizer inbound.

We encourage all pilots to continue to share their observations and concerns. Sharing information just may save a life.

Your APA Safety Committee…Looking out for you.

As noted in my last post on the Colgan accident, the NTSB is keying on the autopilot mode. If the Q-400 was in the approach mode, the aircraft would attempt to follow the potentially erroneous signal from the ILS (Instrument Landing System). However, according to FAA spokesman Laura Brown, this zone of confusion is only present on a Northern turn to final. The Colgan flight was vectored in on a Southern (left) base turn to final, thus the ILS anomaly is unlikely.

The sequence of events is critical, as is the exact position of the aircraft on final approach. The aircraft, IMO, experienced an accelerated stall/departure and then a flat spin. The cause of the fatal nose movement is what is now in question.

One last note; in a past post I mentioned the caveat “assuming the pusher activated in the proper direction”. The NTSB mentioned the same caveat in an article.

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