Again agree with the mechanics of what you are saying, but not entirely with the conclution.
In order that an aircraft maintain altitude it must produce lift equal to its' apparent weight, not just the force due to gravity.
In terms of predicting the result of any physical interaction a bodies apparent weight is actually more important than it's actual weight. Objects in free-fall act exactley as if they were not in a gravity field. Objects subject to both gravity and a normal acceleration act exactley as if they weighed more. Weight is measured with a scale, and in both cases, that measurment would be different to 1g, and there would be no way for an observer to tell the difference between force due to gravity and force (or lack of it) due to acceleration.