Why do helicopters sound so "choppy" on windy days?
It's very windy tonight here in Melbourne, Australia (since last night, in fact!). The VicPol Dauphin just flew over and the rotor blades were so loud (rotor slap?) even though it was just flying forward at speed, not turning or hovering.
I am wondering if anyone can explain the physics as to what causes this extra sound dynamic on a windy day?
Thanks.