- there is no change in the magnitude ground speed of the aircraft when you turn into/out of wind (assuming no motor, no drag, no friction, ignoring increase in speed due to gravity or conversion of gravitational potential energy into KE); I think the big problem is that people forget about a direction change does not equal change in magnitude.
- upon changing headwind/tailwind you will change your "true airspeed" (as far as i know true airspeed is defined as velocity of airmass relative to the aircraft).
David, unless I’m misreading this somehow (and I apologise if I am), it looks suspiciously like a rewording of the downwind turn myth. If you keep all your other assumptions, but change ‘no motor’ to ‘motor set at stable setting for a constant turn’, do your conclusions change at all?
Supposing you fly an ordinary powered aircraft at altitude in a constant 30 degree banked turn, in a constant airmass. You don’t know what the wind velocity is, and don’t care. The aircraft will go round and round in circles. The indicated airspeed (and true airspeed) won’t change at all. The magnitude of the groundspeed will be constantly changing, as long as the wind velocity is greater than zero. The position of your orbits will be moving across the ground due to the wind, but the aircraft doesn’t know this.
Most pilots would agree with all the above, yet a few of those same pilots (some with 20000+ hrs) still believe that their indicated airspeed will increase as they turn onto final into a strong wind. I’m not sure how the aircraft now knows it’s turning towards a runway, and they never seem able to explain this.