Anonymous
Anonymous asked in Cars & TransportationAircraft · 1 month ago

When an airplane is in danger, why don't the pilots just turn off both engines and extend the flaps so as to increase lift and reduce speed?

that way when the plane crash it is slow enough that people can survive?

18 Answers

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  • Sky
    Lv 7
    2 weeks ago

    That may work for a small aircraft, but for an airliner their stalling speed is well over 100 knots.  The best glide speed of a 737 is 114 knots, so at that speed if the impact with the ground or obstructions is hard enough to cause disintegration of the airplane, nobody's surviving that.

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  • 3 weeks ago

    Because some aircraft (airliners) land at anywhere from 120 mph to around 145-150 mph.  Don't think there would be too many survivors from that.

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  • 3 weeks ago

    The stall speed is still over 100 mph and the seat belts are not all that great,  the ones you have in your car are better.  

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  • F
    Lv 6
    1 month ago

    Oh yeh that would work, a 300 ton plane will just float to earth that way. 

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  • 1 month ago

    Define "airplane in danger".

    In the case of US Airways 1549, for instance, both engines were 'turned off' by the impact of several large birds. The crew's objective then was to increase the glide ratio as much as possible to try and get back to the airport, and it so happens that extended flaps may increase lift but also increase drag proportionally more, making the wing *less* effective aerodynamically.

    I defy you to find one instance of an "airplane in danger" that could have been helped by shutting down all the engines and extending flaps.

    And by the way, the survival rate of people in airplane accident is above 95% already (95.7% to be exact).

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  • 1 month ago

    Besides what the others say, the engines on many planes do other functions:

    Supply electric power to the hydraulic system pumps for flight controls and brakes, the panel instruments and radio.  Batteries cannot do all that.

    Supply ventilation to the passengers.  Lack of air from the engines might lead to a rapid depressurization at high altitude.  Emergency masks can supply people for only for a few minutes.

    If a pilot tries a "dead stick" landing with no engine power, he has only one chance to get it right.  Engine power might give a chance to try again.

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  • Joseph
    Lv 7
    1 month ago

    Better yet, why don't they start flapping the plane's wings to bring it to a safe landing and avoid the crash altogether?

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  • 1 month ago

    This must be of the most clueless questions ever posted on this forum.

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  • Because an aeroplane can only be slowed so much before it simply drops like a rock from the skye.

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  • Barry
    Lv 5
    1 month ago

    Like you I know little about aerodynamics. But I do know that reducing speed decreases lift. This leads to stalling. I.e., the plane falls out of the sky. So the plane's stall speed dictates a safe landing speed. Since the stall speed averages 150 mph a sudden stop at that speed is usually fatal. More so when the plane catches fire.

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