ORIGINAL: carl24bpool
If I went out in a 40mph wind would my plane take off on the spot without having to move forward as long as the thrust from the prop was enough to counteract the wind blowing it backwards?
Yes, if the wind were steady enough the plane would levitate like a helicopter. The difficulty is getting it "just right" so that it niether flys forward or backward. I made a hovering three point landing with a GP Dazzler at Speedfest III in Stillwater OK last April. Got a round of applause from everyone
ORIGINAL: carl24bpool
Or is there something about momentum and mass moving in relation to the earth and gravity that comes into it somewhere?
Nope, that's why aircraft carriers sail into the wind to get more airspeed on the aircraft's wings before they take off.
ORIGINAL: carl24bpool
I was just thinking that in a high wind you could have your plane just flying mid air next to you. Or is this a load of rubbish?
Not rubbish, just hard to find wind in air that is not too turbulent that close to the ground.