sinkrate3278

Because of the thin shape of the tail, it will normally ice up much faster than the wing.

So wouldn't this suggest that if you enter a stall in icing conditions in an aircraft not approved into icing conditions that you must assume it must be a tail stall?

This AOPA publication recommends this:

You are likely experiencing a tail stall if:
• The pitch control forces become abnormal or erratic
when flaps are extended to any setting.
• There is buffet in the control column (not the
airframe)

But I don't really see how these two characteristics are dissimilar to the onset of a wing stall in icing conditions?

FlyingChipmunk

I wouldn't assume anything just because your in Icing. Knowing your aircraft and how it behaves in a wing stall will help you better diagnose which type of stall you are dealing with.

I say this because when I had an un expected encounter with freezing rain/severe Icing, I experienced a wing buffet because of the location/intensity of the ice (accumulated during descent).

A tail stall has an entirely different feel in a GA aircraft, like you said the control yoke will buffet and get your attention. Try flaring a 402 during landing with residual ice on the tail and you will find out how that feels .

Cubdriver

We had a pretty long thread on this a year ago.

Tail Stall vs. Wing Stall

Here's another (long) one that followed the Colgan crash.

Interesting Stall Information

clipperskipper

"Try flaring a 402 during landing with residual ice on the tail and you will find out how that feels". It isn't so much the design of the tail, but the mere fact that ice accretion on the tail can be three times greater than on the wing due to the induced airflow from the propellers. NASA has some pretty good info on tailplane icing, and tail stall recovery. Combine this with a bad set of counterweights, and a no-gyro approach, and you've got your hands full.

Cubdriver

Here's the famous NASA video-

NASA Tail Plane Icing video

For a generalized tailplane icing recovery to be superceded by your ops manual:

Recovery from a Tail Stall

• Recognize buffeting in control yoke as distinguished from airframe buffeting
• Pull back on yoke
• Reduce flaps to previous setting
• Reduce power- or use judiciously

The key is being on the lookout for unusual stick forces when you start setting up for the approach after flying though icing conditions. If the stick is soft in the forward direction that would be a sign, and certainly any sort of yoke buffeting would be another.

rickair7777

I would NOT assume that...the wing is more heavily loaded than than the tail, and tail loading is very CG-dependent.

clipperskipper

More heavily loaded as in weight, or thickness? Beech 18, C-402, DHC-7 pick one, and I can show you three times the amount of ice on the tail, as on the wings. Plowing through the Northeast Corridor has its disadvantages.

Cubdriver

I don't have any experience of tail plane stalls and hope never to, but studies show that ice accretion is faster & heavier on tail planes than main wings due to thinner shapes. Icing will show up earlier & more prominently on the tail. While a badly out of CG airplane could possibly have light tail loading in cruise, it is inconceivable such a condition could continue into approach because the center of lift on the wing moves aft with flaps and the tail has to generate more force. Light twins can fly approaches with no flaps, but transport aircraft use flaps on approach practically to a one. You'd know if it had trouble maintaining solid flow on the tail assuming a non-hydraulic airplane, although I admit it seems like something within the realm of possibility not to feel a buffet. If the flow reattaches prior to reaching the elevator the stick will not feel a buffet, it will simply feel softer in pitch. On the other hand, without a buffet you do not have an incipient tail plane stall either so perhaps it does not matter quite as much.