Originally Posted by
Gadget freak
Try throwing a ball into the air while driving along in a car. Just after throwing it up have the driver turn sharply. What does the ball do, stay within the cars frame of reference, moving with the air mass?
It will move sideways (relative to the car). Once not in contact with anything in the car, the ball is not accelerated by the car as the car accelerates sideways in the turn and will maintain its straight line motion (relative to the earth) as it is not being accelerated by any force (other than minutely by air resistance).
In your analogy it appears the ball would be the aircraft and car and the "air" contained in the car would be the wind, is that correct?
If so, in that analogy, by turning the car rapidly, you are causing a sudden change in the direction of the "wind", not a change in direction of the "aircraft".
Of course if the wind direction or magnitude changes rapidly there will be IAS changes and that is seen when flying in turbulence or with windshear.
Perhaps we need to define the myth we are arguing against or the phenomena we are arguing for.
If we are talking about turbulence, varying wind speeds, windshear situations etc then of course, IAS will vary as we encounter changing wind velocities.
If the wind is steady and we perform a constant rate turn in a wind, the myth I will argue against, is that the airspeed will vary as the aircraft changes direction from flying the into wind direction to the downwind direction. In a constant wind, it won't.
I spent many hours in my early flying years low to the ground circling around stock in many different wind conditions from dead still to steady flow to strong and gusty days with lots of thermals. Always I found the aircraft flew relative to the air, any variations in airspeed were due to turbulent flow and didn't limit themselves to any particular part of the orbit.
Early on I had to learn to resist the very strong urge to over bank or over rudder the aircraft in strong steady winds due to the illusion the aircraft was skidding or slipping when orbiting low level in a wind. There be dragons.