Tailplane Icing Tested, Explained – by NASA

by

Check out this tape from NASA’s Glenn Research Center in Cleveland. It is 23 minutes long, but it is worth your time if you want to fully understand what might have happened to Colgan/Continental 3407. It explains the phenomenon of Tailplane icing in stark, frightening detail.  The key points: the horizontal stabilizer collects ice faster (and holds more of it) than the wing. It is impossible for a flight crew to see this. NASA says if the crew sees any ice at all on wings, they should assume there is more ice on horizontal stabilizer. The problem is often discovered on approach – when the flaps are extended. If the tail stalls at that point recovery is very difficult – if not impossible. Flying on autopilot you would never feel the symptoms of TP icing – which include difficulty trimming the airplane – or oscillations.  In severe cases of TP icing, the yoke goes all the way forward to the stops – and it requires 170 pound of pressure to pull the back on the wheel. Full deployment of flaps is not advised when there is ice on the stabilizer. Film shows dramatic testing of this kind of icing – and its impact on a de Havilland DH6 (the Otter) – cousin to the Dash 8 that crashed on approach to BUF.  Chilling point to remember: Lowering flaps is the trigger. When you lower the flaps, the yoke shakes, and it seems just like a typical wing stall. But if you try a standard wing stall recovery, “you and your passengers could become history,” says NASA. Tip of the hat to Jon Regas for finding this. Link to video here.

Advertisements

9 Responses to “Tailplane Icing Tested, Explained – by NASA”

  1. Pati Mc Says:

    Great info Miles. You are ON this. (no surprise there)…

    There was a gentleman named Glen on the AC 360 blog last evening – he is a pilot – and he spoke of this very thing. Having spent much time in the air with my Grandfather, this makes total sense.

    So appreciate the fact that you are taking the time to keep us informed. Your heart and soul is in it…that is apparent.

    Take good care. Look forward to hearing about Kenya.

  2. Don Shade Says:

    As a 1,500-hour instrument-rated pilot who is studying for my Commercial written test, I’m amazed I haven’t been taught about this type of icing/elevator stall phenomenon. Thank you for bringing this NASA video to my attention.

  3. Sara Says:

    It will be interesting to see what comes out of this investigation and if training events of professional pilots will be forced to include tailplane stalls in their training- right now it does not. If any airline is doing it they are doing it on their own. Of course this is an assumption of what occurred but their sudden disappearance off the radar and the small crash site (and like you mentioned a time where the flap setting would change) – well it was what I immediately thought of. I have seen tailplane stalls mentioned in winter ops sections of some aviation company manuals but unless a simulator instructor wants to show (and has the time) how this stall differs from their regular training a pilot would not be exposed to this unique scenario.

  4. Colin Says:

    Any thoughts on the latest report that 3407 landed flat on the house and faced the opposite direction of the runway? The former, that it landed flat makes more sense per the early witness accounts as opposed to a nose dive early reporting. But the part where they’re saying the plane was pointed Northeast seems a rather strange twist, unless it flipped over at the last second.

  5. gyrfalcon Says:

    NTSB says this afternoon that the plane had boots on the wings, heated propellers and some kind of deicing equipment, I didn’t catch what, on the tailplane, and that all appeared to be functioning and deployed, according to the FDR.

    Is there any way tailplane stall as a result of icing could have occurred anyway, or does this mean there was some other problem?

    On the direction the plane was pointing, I think I remember it being said it was still in the process of going around to then head to the runway, and therefore temporarily heading away from it.

  6. Miz Says:

    Thank you so much for the information. I miss you on CNN and suspect they miss you as well. Your explanations are such that even someone like myself who is weak in science can understand what may have happened.

  7. Ed Says:

    Miles,

    As always, awesome analysis! As a Clevelander I recently got to visit NASA Glenn during their summer open house and got to see these testing facilties first hand. It is really a gem of a facility that is totally overlooked by the local community (The city of Cleveland gave Glenn to the city of Brookpark in a misguided land swap deal!) but I digress.

    It seems like this video is written next year explaining the crash vs. 11 years ago. Another example of the economy of risk management, hopefully this will lead to better procedures but still so sad this had to happen to now make the problem important.

    Miles, I think you need to see if CNN wants you back as a freelance consultant on this, just make sure to charge them 2.5x your previous rate!

    Miles for National Science Advisor!!!

  8. Matt Says:

    Miles,

    As a part 135 charter pilot we use this video as part of our training program each year when we cover flight into known icing conditions. There are many valuable lessons in this video about how an aircraft performs during icing. Memory item 1— visible icing. Auto-Pilot OFF.

  9. Heartburn Home Remedy Says:

    This is quite a up-to-date information. I’ll share it on Facebook.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: