SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/pilot-gyroscopic-precession

When a force tilts a spinning propeller, where does the resulting force act?

90 degrees ahead in the direction of rotation.

  1. 90 degrees ahead in the direction of rotation ✔
  2. Exactly where the force was applied
  3. 180 degrees opposite the applied force

Why: A spinning propeller acts like a gyroscope. Push on its rim and the effect shows up 90 degrees later in the direction of spin. Raising a taildragger's tail on takeoff yaws the nose left this way.

Huh, didn't know that: Because of gyroscopic action, any yaw makes a pitching moment and any pitch makes a yawing moment.

The dad joke
Why did the gyroscope get promoted? It always kept its balance.
Like this card?
Play the game

Sources

  1. FAA Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 5 https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/faa-h-8083-25c.pdf

Test yourself in the game

Flying & DronesAt a high angle of attack, P-factor yaws a typical single-engine airplane which way?Flying & DronesThe propeller's spiraling slipstream strikes which part of the airplane?Flying & DronesIn straight, level, unaccelerated flight, lift is equal to which force?

That's stuff everyone should know.