Originally Posted by
rickair7777
Executive summary....
Snow accumlated around the LOC antenna, casusing the LOC beam to be off center by 200'
Several crew (including the accident FO on a previous flight) experienced this in the preceeding five days but did not report it.
The arrival prior to the accident reported it, but FAA policy was that action would only be taken (such as placing the LOC OOS) if two or more aircraft reported problems (in case the first aircraft had bad avionics). Policy did say to switch to standby equipment, but there was no local tower to do that.
Crew kept descending below minimums with runway environment not identified, until impact.
FAA did change policy to require snow clearance around LOC antennas (previously only required around GS antennas).
The report had some interesting details on the boldface part. This is a pretty interesting human factors read.
A lot of the errors are from reasonable assumptions:
Many of us know that snow piles affect ILS signals. A good number know this affects localizer as well as glideslope signals. So it's understandable (not acceptable) that this wasn't reported by other crews. Many years ago I was based in Presque Isle. The town was a shell of its former self, and it hasn't grown since then. So is a small town airport going to deviate from procedures that have been working for Colgan, Commutair, Wiggins, AirNow, etc. for years? A brand, spaking new FO expects a captain to have some judgement and experience. The captain directs the FO to stay inside on the second approach, and the FO does. This also is understandable, but not acceptable. That captain expects the localizer to work as expected, gets needles and identification. She never considers that the signal may be off. This is also understandable.
I'm always making noise about something. Conflicts of interest, training curricula, GPS spoofing, etc. I'm fully aware of the political costs of speaking out. Others use that awareness to navigate promotion pathways (I've done so in the past. No judgement.). So there's real-world pressure on these crews to shut up and keep up. There was real-world pressure for commutair to get this particular captain through. A probationary FO feels real world pressure not to upset whoever's in the left seat.
The swiss cheese aligned in some pretty relatable ways here. Many of our own operations can and have experienced similar things. Not being a Commutair guy I can't speak to what goes on or went on there. I would wonder what pressures crews felt not to report things.