Not considering pilot reaction time, what factors influence a helicopter's ability to survive high wind gust spreads (from any direction) during takeoff and landing?

I have considered:

  • Swash plate delay: assuming an example main rotor spinning at 600RPM, the rotor completes 10 rotations per second. If each control input requires 180 degrees of rotation to take effect, then fastest possible reaction time is an adjustment every 1/20 second.
  • Mass of the aircraft: a heavier aircraft will be moved a shorter distance by crosswind gusts. This reduces the likelihood a skid will unintentionally strike the ground during the earliest stages of takeoff or the final stages of landing (1inch to 3ft off the ground), which could result in the gust building under the vehicle and causing a roll.
  • Rotor system: rigid and articulating rotor systems are not susceptible to mast bumping.


  1. How do you rank these factors in order of largest influence on surviving high wind gusts during takeoff?
  2. Are there other factors I have not considered?
  • $\begingroup$ Swashplate delay is not in rotations. The point of swashplate is to adjust the blade pitch differently according to their position, so the blade pitch must precisely follow the swash plate position. Control delay is because it takes some force, and thus time, to adjust the swash plate (by pilot or by hydraulic actuators if involved) and because the swash plate only sets rate of tilt and the maximum rate of tilt is limited by the available blade pitch range and resulting lift and the rotational inertia. $\endgroup$ – Jan Hudec May 13 '20 at 7:44
  • $\begingroup$ Thanks @JanHudec - I will further dig into swashplate mechanics $\endgroup$ – max May 14 '20 at 16:15
  • $\begingroup$ Not an engineer but I would assume disk loading, and rotor tip speed are major players in the game. higher disk loading, and faster tip speeds would likely be much less susceptible to gusts, looking forward to someone who knows what there talking about. Vary Effective tail-rotors are necessary if the gusts are not right on the nose $\endgroup$ – wanna-beCanadianPilot Sep 5 '20 at 0:24

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