Ya but the dimples go the wrong way. Maybe speed whistlers
Exactly. Speed whistlers are a better idea than a baseball card clothes pinned to the cowling for the propeller to to make noise.
“Never feel sorry for a man who owns a plane.” -Charles Morse (Anthony Hopkins) Movie - "The Edge" https://youtu.be/dJD0lB4zRes "...except during the month of Annual Condition Inspection." -Me (in the hangar)
"My first wife didn't like airplanes." - Gordon Baxter