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Would cyclic control inputs be backwards from a rapid spin ?

Gyroscope precession

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#1 Weads

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Posted 09 October 2017 - 15:22

Assuming a rapid spin was able to build from lte or complete loss of tail rotor would gyroscopic precession eventually make cyclic controls inputs backwards? Bit of a hypothetical question but any insight is much appreciated

#2 Wally

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Posted 10 October 2017 - 13:45

Assuming a rapid spin was able to build from lte or complete loss of tail rotor would gyroscopic precession eventually make cyclic controls inputs backwards? Bit of a hypothetical question but any insight is much appreciated

Why would fuselage rotation reverse cyclic input?  No.


Just a pilot (retired, so I have a LOT of time)...


#3 rotornut67

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Posted 10 October 2017 - 14:43

     A spin from the loss of a tail rotor can be so rapid (360 deg in 2 seconds or less) that the human eye cannot move fast enough to keep up with where you are at in the rotation.  By the time your brain processes and the input is made you are likely 180 deg opposite of where you think you are, hence the perceived control reversal.  I've experienced it numerous times in a Level 7 FTD and it's a ride I pray I never have to take for real.

     When the nose even hints at going where you don't want it to go APPLY the appropriate pedal!!!!


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#4 Weads

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Posted 10 October 2017 - 19:11

Why would fuselage rotation reverse cyclic input?  No.

. Gyroscopic precession

#5 Wally

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Posted 11 October 2017 - 10:32

" Gyroscopic precession" is not rate dependent.  The rotor turns the same way at the same relative speed to the fuselage.

Rotornut67's answer would be correct in my estimation.  I would expect that the average pilot would be disoriented  perhaps to the point of incapacitation pretty quickly.  It is astonishing how dramatic and quickly the change occurs.  If you don't have your hand on the power control before that first turn is complete, I don't think you could get it there.


Just a pilot (retired, so I have a LOT of time)...


#6 Eric Hunt

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Posted 14 October 2017 - 05:57

Oh dear, Weads still believes in gyroscopic precession.

 

One of the secondary effects or yaw (pedal input, or lack thereof) is roll. Combine a rapid yaw with a slight roll, and the rotation of the aircraft is no longer level, it is tilted towards the ground, hugely disorienting. One or two turns later, the tail boom hits the ground. Bye-bye.


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