Dan_Thomas_nospam@[EMAIL PROTECTED]
wrote:
> On Dec 27, 10:07 am, Dudley Henriques <dhenriq...@[EMAIL PROTECTED]
> wrote:
>> Todd W. Deckard wrote:
>>> But the links that Dan_Thomas sent me indicated that the airplane
would not
>>> stall "straight ahead" if you were in a climbing turn. The outside
wing
>>> has a higher AoA
>>> which diverges even further as it initially drops.
>> Dan isn't wrong.
>> Climbing turn stalls are a bit complicated to nail down to a strict
>> behavioral pattern as each airplane and indeed each stall entered in a
>> specific airplane will probably be exhibiting slightly different stall
>> behavior due to varying control inputs by the pilot. The result of this
>> is that climbing turn stalls can produce different results depending on
>> what the pilot is doing with the airplane up to and at the instant of
>> the stall break.
>> Basically, if you are (as we say) coordinated, the top wing will stall
>> first and the airplane will roll off in that direction. The reason for
>> this is that as the stall is approached both wings start losing lift
>> causing the airplane to mush into a slip. The highest wing gets
>> interference from the fuselage and usually quits first. If you watch
the
>> ball as this happens, as you get near to stall, you'll probably notice
>> that if you can't hold it centered, and a slip develops, that high wing
>> will usually be the one to go first.
>> This doesn't always happen however :-)) and if you skid the airplane,
>> the bottom wing can break first.
>> The bottom line is that in most climbing turn stalls, you will get a
>> roll off as the stall breaks, but remember, this is a ROLL OFF, not a
>> yaw rate!! Just reduce the angle of attack and use aileron to raise the
>> lowering wing and no pro spin forces are present.
>>
>> --
>> Dudley Henriques
>
> But we've had full-blown spins develop from the climbing-turn
> stall. If the pilot isn't expecting it, it will roll off the high side
> and start yawing in that direction, and if full power is still on it
> can get violent. It'll spin readily, as this re-quoted excerpt states:
>
> "Full power stalls in a balanced climbing turn tend to result in the
> outer
> wing stalling first, because of the higher aoa of the outer wing, with
> a
> fairly fast wing and nose drop (particularly so if the propeller
> torque
> effect is such that it reinforces the roll away from the original
> direction
> of turn and the aircraft is a high wing configuration) and likely to
> result
> in a stall/spin situation that any pilot lacking spin recovery
> experience
> may find difficult to deal with."
>
> By "balanced" I presume these Aussies mean "coordinated." And if
> the stall is fully developed the aileron won't help and might
> aggravate things.
> Of course if the pilot gets the nose down quick, and uses rudder
> rather than aileron, it will recover OK. But he has to understand
> immediately what's happening.
>
> Dan
It's nothing unusual for an airplane to spin out of a climbing turn
stall.....IF yaw isn't corrected as the stall breaks. It depends in a
large part on how ham handed the pilot is as the stall is approached.
The break can be clean nose down, usually high wing first, and can even
be low wing first. In ALL scenarios, yaw must be eliminated from the
equation as the stall breaks to prevent spin. If the angle of attack is
recovered normally as the stall breaks, even if roll off is present, by
coordinated use of flight controls raising the wing and the yaw is
eliminated, a normal recovery will be accomplished.
If the pilot applies incorrect control responses and doesn't eliminate
the yaw, the combination of stall and a yaw rate can easily spin the
airplane.
These power on climbing turn stalls can be done all day long by pilots
using proper recovery technique as the stall breakes with absolutely no
spin issue in the recovery equation.
--
Dudley Henriques
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