p51Dpony, rjbob, Tim (parachute example) make my point better than I did.....and true, perhaps folks in the a/c do not detect minor accelerations(maneuvers), though they would if abrupt enough (my 100-200mph, for example, and much less extreme ones).

All posited frames of reference 'making a difference' are moot...they cancel out, so long as there is constant speed or such minor accelerations as to be unnecessary to consider (earth/sun/universe). Comes down to the simplest frame of ref that has meaning and where there are actual/significant speed changes: a mass in the air that changes direction. Our model. And if that mass changes direction or speed, then there is an effect on it.....whether being observed form the ground or aboard. And so it will slow, or speed up, drop or rise, as conditions change (going from UW to DW, etc.), unless actively compensated for.

Recall: the original issue here is the effect on the mass (a/c) of a maneuver...not necessarily what folks observe...though it's certainly observable. You (the wind or prop/turbine thrust) simply cannot bring that mass back up to the same AS instantly, there is a lag, and that lag can produce (for one) the effects of 'the dreaded DW turn'. Sorry, but again (in our classical conditions, anyway), F does equal Ma.

Mike, I meant to answer earlier: I'm a retired mechanical engineer, though that's hardly a credential here. Commonsense and an open mind suffices. The aero phds/books are not wrong...but most often they are speaking of specific cases/conditions, eliminating variables/difficult quantities in order to clarify/solve an aero problem, etc.

Really.....just go out and observe it. Turn fast from UW to DW, esp w/ a heavy highly WLed model. Do nothing but get it to turn...and watch it drop. POV does not matter (someone said correctly inertia is a property of the object/the a/c). It will drop because it has to, as it has lost AS.

Ray

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