Originally Posted by
KC10 FATboy
I flew Beech 1900's for the USAF. While I was there, an air directive came out about tail icing. I believe this was in response to the ATR crash that was holding for approach in Chicago. There was also a video we watched from the FAA which was created by NASA.
Essentially what TZADIK posted is spot on. For T-Tail aircraft, due to the flow of air over the wing which effects the flow of air over the T-Tail, this can lead to significant ice build up on the T-Tail. In fact, if you see a little ice on the wings or cockpit, you already have TOO MUCH ice on the tail. NASA showed video of the wing and T-Tail of a plane that was flown into heavy icing. Even though the wing had maybe an inch of ice on the leading edge, the tail had 4 times as much! They also showed recovery techniques which are the same as given above and are opposite for a normal wing stall recovery.
This air directive changed how often and when to blow the boots on the Beech 1900 and the procedure was changed in our manuals.
I have to admit, I am kind of surprised that this is something new for the guys who are flying T-tails. If you don't know it.
-Fatty
It's not something I remember from any of my training, we may have talked about it, but it certainly wasn't anything we mulled over for a long time as I don't remember it. Either way, better learning about it late than never. Do you suggest any good reading material that I can use to further educate myself on this? I try and take my job as seriously as I can, and I realize I have a lot of responsibility so I have no problem admitting to not knowing something. My grandfather told me once that "There are old pilots and there are bold pilots, but there are no old, bold pilots." I want to be the old one.
So I was also doing some snooping around, and apparently back in December of 1989 out in Washington state, there was a United Express prop plane that went down as a result of icing, and it sounded from what information I could gather similar to what we are talking about here. It's United Express 2415 I think it was. Here is a link to the NTSB about it.
DCA90MA011