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IDLE RPM AT HIGHER ALTITUDE

Asked by: 1760 views Aircraft Systems

my question is that why idle RPM is higher at higher altitude?

if tachometer is reading higher idle RPM at higher Altitude, thrust produced will be more or not?

 

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1 Answers



  1. Nathan Parker on Oct 12, 2012

    When you glide with the engine at idle, you’re probably not developing any net thrust at all. Or rather, your net thrust is negative, because the relative wind is driving the engine. The relative wind will cause the RPM to increase because the lift generated by the propeller blade acts somewhat in the direction of rotation. This effect is augmented at altitude.

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