FAA Private Pilot Helicopter (PRH)Helicopter Aerodynamics and SystemsHard

A helicopter is loaded near its forward center-of-gravity limit. What flight condition is this loading most likely to adversely affect?

  1. AThe ability to maintain level flight at high cruise airspeed, due to insufficient forward cyclic authority
  2. BThe amount of tail rotor thrust available for anti-torque control at high power settings
  3. CThe ability to achieve a nose-high attitude during hovering autorotation or a landing flare, due to insufficient aft cyclic authority
  4. DLateral control during sideward flight, due to insufficient left cyclic authority
Show answer & explanation

Correct answer: C. The ability to achieve a nose-high attitude during hovering autorotation or a landing flare, due to insufficient aft cyclic authority

With a forward CG, the nose tends to pitch down, requiring the pilot to hold more aft cyclic just to maintain a level attitude or hover. This uses up available aft cyclic travel, so less remains for maneuvers that require additional aft cyclic, such as flaring during autorotation landing, potentially resulting in a nose-low, high-speed touchdown.

Why the other options are wrong

  • A. An aft CG condition, not forward, restricts forward cyclic and high-speed flight capability.
  • B. CG position along the fore-aft axis does not directly limit tail rotor thrust availability.
  • D. Lateral CG issues affect left/right cyclic authority, unrelated to a fore-aft CG limit.

Forward CG Flight Effects

A forward center-of-gravity loading requires more aft cyclic to maintain attitude, reducing the aft cyclic reserve available for maneuvers like the autorotation flare.

  • Forward CG causes a nose-low tendency
  • Pilot must hold more aft cyclic to compensate
  • Less aft cyclic remains available for flare/hover
  • Aft CG has the opposite effect, limiting forward cyclic and high-speed flight

Memory trick: Forward CG eats your aft cyclic 'savings account' before you need it to flare.

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