DispatchDragon wrote:Andy
Most of the big Ham-Standard props ie T6, Stearman, Waco, N3N - are close enough to be noticeable - hence the very distinctive sound on takeoff of all of these aircraft which for reasons some scientfic type is about to tell me - seems always more pronounced in very humid conditions
Leif
Certainly is close enough to get affected Leif
The Harvard's distinctive rasp is caused but the near sonic tips.
Heralds also used to let out a chatter at time due to the tips getting into or near the no no area in certain especially damp conditions
That is also why rotors 'chop'
Aurigny Trislanders have three bladed props now to slow the speed and get away from the noisy end as the tips when right up near the sonic speed.
They may not get supersonic but props or at least the older ones got close enough to start making a noise.....literally
Garry
Garry