Ice in Turboprops
 

Any charter/corp/time share pros have horror stories or thoughts on ice in GA turboprops? Ever unable to climb or hold altitude? Ever have a wing fall off with no shaker/pusher warning? Ever not go due to inflight ice? If yes, what is a no go situation (beyond freezing rain)? How many times per year do you "must go" guys delay due to ice? Will more speed solve all, if able to tolerate no climb?

Well, I have just around 1200hrs on both GA and regional turboprops and had just one hairy moment regarding the icing. We were climbing through FL160 (on the nice, warm summer day over the central Europe) and started to pick-up so much ice (and so quickly) that our faithful ATR 42-320 was unable to climb any further. We immediately requested a descend to the lower level, which solved our troubles quickly. But don`t forget the -320 when loaded climbs like the Wellington on the Berlin raid, King Air and other biz-props do much better

So basically the old advice is - change the level (2-3000ft is often enough) and the icing usually stops. And never try to climb above when the performace is not sufficient, it can (and does) lead to the wing fall off (happened to friend of mine many years ago). And if really in troubles , don`t forget that AoA is everything when the wing is contaminated, which basically means the speed up. But again, if able to go lower, do it instead of holding the level with increased speed, it can be matter of time when the ice build-up is so huge that you are in troubles again. Speed increase is only temporary solution.

On the other hand I cannot remeber the situation when we had to stay on the ground with the jets going. Of course I would postpone the departure when the severe icing is reported in the lower levels, but it never happened to me even during the winter.

By the way, contrary to the popular but incorrect myth, the ATR when properly operated can cope with the ice wery efficently and safely. The two-chamber de-icing boots are really good!

After the mods you mean?

Friend of mine flew the route of the first ATR that crashed in the alps about 10 minutes in front of them with a KingAir 90 and had his airplane stall on autopilot. He made it into Bergamo and stayed there for the night. His warning about severe ice was never relayed to the ATR crew.

I had ice on a KingAir 200 about 2 inches thick in FL180 and had to descend over the irish sea. Not a pleasant experience. Stay above the minimum speed in icing to prevent under wing icing, as you cant see it and cant get rid of it.
Be aware of the possible Tailplane stall and what you have to do to unstall it.

There is several excellent NASA videos on the subject:

Be cautious to make sure it's a tailplane stall. There was a popular rumor going around that the Colgan 3407 captain was attempting to recover from a tailplane stall. Had it not been for other errors he made I probably would have jumped on that bandwagon too since his reaction was appropriate for a tailplane stall.

I've never had ice get too bad, but then again I've only got about 1500 hours so I've got lots of time to play with the cold stuff. Just keep an eye on it and be smart.

Happened to me 5 times last week, and three times already this week. But I just stick it back on again with some ductape & off we go again.... :E

Aircraft Icing Training - A Pilot's Guide to Ground Icing

It's for free and well worth the time. Icing is a killer dont get caught with your pants down.

6500 flight hours on ATR 42/72-500, in europe,...what can I say is to monitor carefully the speed while in ice accretion, and to select flaps15 if speed comes below red bug....otherwise if deicing systems are working properly, is no reason of fear, but, never try to climb, if terrain permits you have to descend, and be aware 1degree celsius is enough to escape from severe icing.
Nice flights!

THIS could be helpful too. Better if you read it BEFORE things go "...oh-s...ugar!"

DK :)

Have had two tail stalls in 15K hours, both in C421s when tail boot valves failed. The symptoms included pitch excursions and a 'buzz' through the yoke when the stall occurred. Not fun!!

Biggest thing is stay out of ice and , if you find yourself in it, get out. Icing here in the Great Lakes area is usually no more than 4,000' thick, though I have seen icing conditions 8-10K thick. Almost all piston aircraft, deiced or not, don't do well in icing. Turboprops have better climb performance which is great. If descending, increase descent within reason to minimize exposure duration.

Don´t forget belly ice build up, if yoy have high AoA you will getting lots of extra pounds under belly, wings, and Horiz. stabil. Maintain high speed and descend to warm level to clear ice. And don´t forget to use your deice systems properly ( I mean boots)