Emergency Descent

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FastEddieB
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Re: Emergency Descent

Postby FastEddieB » Thu Dec 20, 2018 11:58 am

MrMorden wrote:I an see using the turn to add drag and increase the descent rate...but now you are at relatively low speed in a 2g bank, and risking an accelerated stall...


Simple geometry shows that a 60° bank results in 2 g’s and about a 40% increase install speed.

But that’s only when maintaining altitude. In this exercise, we’re allowing the nose to fall, which unloads the wings, which can result in not much more than 1g, and hence little or no increase in stall speed. So, with the speed near the maximum for the flaps selected, stalling should not be a major threat.
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drseti
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Re: Emergency Descent

Postby drseti » Thu Dec 20, 2018 1:19 pm

FastEddieB wrote:But that’s only when maintaining altitude. In this exercise, we’re allowing the nose to fall, which unloads the wings, which can result in not much more than 1g, and hence little or no increase in stall speed. So, with the speed near the maximum for the flaps selected, stalling should not be a major threat.


Bingo! In fact, as you descend, you're loading the wing at less than 1g. And the speed I selected for my plane is halfway between stall speed and max flap speed, so you have plenty of wiggle room in both directions, and don't have to be staring at the airspeed indicator.
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Jim Hardin
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Re: Emergency Descent

Postby Jim Hardin » Thu Dec 20, 2018 5:34 pm

Just a reminder about Load Factor.

Many LSA's have their Load Factor cut in half once you add flaps. That should be a consideration depending on the conditions at the time.


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