What is "aircraft stability" - IN VIDEO

[klem]

Originally Posted by Crumpp

Exactly. It must be controlled at all times and the pilot must watch his accelerations as he can overload the airframe much easier than other aircraft.

You can see the RAE measurements do not match the game in the most basic of stability characteristics.

The RAE measurements where chosen to be reproduced because of there can be no argument.

A small group of players felt like constantly attacking the NACA data as it was not gathered by the RAE. It was decided to concentrate on reproducing the RAE measurements.

The RAE measured the stability characteristics stick free by recording the oscillation over several minutes.

If you break it down into smaller time elements, you can see the Spitfire is rapidly changing speeds over just a few seconds.

Those oscillations must be controlled by pilot input and as the airplane is not stable, they must be constantly managed.

It is not a stick setting issue but one of the basic flying qualities of the aircraft. Joystick parameters have no effect on it.

Here is what the RAE measured:



Here is the results, the aircraft is neutral or unstable dynamically stick free.



Here is the result of the ingame testing. The conditions are the same. The stability is recorded stick free at 5.46 minutes. At that point the airplane is both static and dynamically stable, something the real aircraft was not during the Battle of Britain.







Never flew a Spitfire without an inertial elevator. In otherwords, he describes the aircraft AFTER the longitudinal instability was fixed.

I don't want to get dragged into this but as its my chart that's being used, two things to observe:

1. It was a quick test which I would like to see others repeat although I did go to great lengths to ensure I was trimmed as stable as possible hands-off.
2. It isn't really stick-free as my stick is held central by the springs, so a 'light hand' on the stick if you like. We can't represent stick-free unless someone has FFB (I know nothing about how FFB sticks would be affected by this). That might do it.