[Crumpp]

You are about to be ignored. I know very well what the formula's are for as I am degreed in Aeronautical Science.

Once more I am pilot and aircraft owner so I see these affects first hand every time I fly my family on a trip. It's not some academic exercise.

Now go back and find where I said anything about there not being a relatively small top level speed reduction due to weight affects. No one has ever claimed anything but that. Graham is the only one who has tried to narrow the issue to that one subject.

Instead of having a nice conversation, we are dealing with your lack of understanding on how a parametric study works to determine the affect of something. Parametric study is the most common and accepted way of determining the cause, effect, and magnitude.

My issue has always been that Graham's original post:

Actually, fuel state is not that important with regard to maximum speed.

Is not true because one cannot separate the affect as Lift, drag, and Angle of attack all have a fixed by design finite relationship. If the only affect of adding weight was small reduction in top level speed, then we could say it was insignificant.

It is not insignificant. That small drop in level speed represents a very significant reduction in the aircrafts entire maneuvering envelope.

In no way, shape, or form can we say that weight does not matter and has little affect on the airplane.

All considered it’s a healthy concept to keep in mind: the flying weight of your aircraft directly affects its performance. Each time. Every time. No exceptions.

http://www.principalair.ca/article-weight.htm

All the best,

Crumpp