PPRuNe Forums - View Single Post - Serious wing drop at stall
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Old 4th May 2004 | 18:50
  #10 (permalink)  
DFC
 
Joined: Mar 2002
Posts: 2,814
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From: Euroland
Those who advocate the application of full power before moving the control column forward should remember the secondary effects of increasing power - pitch and yaw. Most trainers will pitch up and yaw to the left when increasing power. If you are using the elevators to reduce the angle of attack (recover from the stall) the last thing you need is to have to work against a pitching moment caused by a sudden increase in power.

As instructors we frequently have to remind both students and PPLs to apply rudder when increasing power to enter a climb........if they can't keep the aircraft balanced there does anyone think that they will be able to apply full power while stalled and remember to prevent the resultant yaw.

When stalling with flaps, lateral stability is reduced.

With power applied, we can prevent any yaw with the rudder but as speed reduces, the torque from the engine can cause a rolling force which needs to be counteracted with aileron...thus putting one aileron down, thus increasing the angle of attack on the outer part of a wing that aleady has reduced lateral stability with flap extended.

The result is that one is more likely to get a wing drop when stalling with power and/or flap.

SSR is stick forward, full power establish the aircraft in a climb.

The stall recovery comes from reducing the angle of attack - moving the stick. Minimising the height loss comes from the use of power.

Note - if the nose drops significantly during the stall and recovery, adding power may simply accelerate the aircraft towards the ground. In such a case, it may be more prudent to delay application of full power.

-273,

You mention recovery from Vmc.....are you not mixing up Vmc and the stall........they are two totally different things. If the aircraft is departing from controlled flight below Vmc then it must be a multi and the only recovery option is to reduce the power on the operating engine......that is why it is called Vmc

Regards,

DFC
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