Originally Posted by
Ian W
A^2 I think you are getting carried away with the turns being air radius turns and forgetting your basic physics the the aircraft is actually ground referenced, for acceleration and deceleration. .
No, I am not forgetting my basic physics. Whether you use the frame of reference of the ground, or the air, the acceleration is the same. Acceleration is independent of frame of reference, assuming non-accelerated frames of reference, which (for our purposes) both the ground and a uniform air mass in constant motion both are.
Originally Posted by
Ian W
1, Take a 3 ton weight that is stationary that then turns along a rate 2 turn radius and accelerates to 120kts in 30sec
2. Take a 3 ton weight that is traveling at 120kts that then turns along a rate 2 turn radius and decelerates to stationary in 30sec
Your argument is neither of these weights experience any acceleration.
No, my argument absolutely is *NOT* that neither experience any acceleration. The velocity of each changes, so by the definition of acceleration (change in velocity), they both experience an acceleration. I have no idea where you got that. What I did say, is that the same a weight accelerating from zero to 120 knots to the West experiences the identical change in velocity as the same weight accelerating from 60 knots east to 60 knots west. Both experience a change in velocity of 120 knots, regardless of frame of reference.
Yes, the radius of the turn relative to the ground will be different for the case with the wind. No, it does not make any difference because the ground is not accelerating the airplane. The only thing touching the airplane is the air, so the air is the only thing which can exert force on the airplane, so the only turn radius that matters is the turn radius of the airplane in the frame of reference of the air mass, which is identical for both the wind and zero wind cases.