Stability and Control characteristics of the Early Mark Spitfires

[NZtyphoon]

Originally Posted by Crumpp

That empty weight CG for that specific aircraft then has its specific range for foward and aft limits based on its authorized configurations. That is why the weight and balance is part of the Pilot's Handbook for that aircraft. It is required documentation and just like the Handbook, propeller logs, engine logs, and airframe logbooks follows the aircraft throughout its life.

Completely wrong, neither individual CG drawings, nor weight and balance sheets were issued with the Pilot's Notes - fighter pilots especially were rarely allocated their own aircraft and had to take what was made available. Pilot's Notes General, Section 7:


Each and every aircraft type used by the RAF and FAA had generic cg/w&b sheets printed, which had fixed fore and aft limits, beyond which the flight qualities started to suffer: Lancaster cg drawings:



Loading diagram up to L7532...


L7533 on...


Careful study shows the cg limits fore and aft were identical, despite different equipment and loadings - the airframe was the same, so the limits stayed the same - those fore and aft limits for ALL early Marks of Merlin engined Spitfires were identical, Mk I to Mk V and were not changed until the modified elevators with larger mass balances were introduced.

It was the responsibility of the groundcrew to ensure that the cg limits were adhered to. The only crews that needed to know the position of the cg were bomber crews with their large disposable loads and multiple crew positions

This is how the cg was calculated:







Relatively small changes in equipment weight and equipment position could still make a big difference to the final cg - a few kg a few inches aft of the rearmost cg position could upset the handling of an aircraft;

NACA made it quite clear that their calculations for the Spitfire may well have been in error - until Crumpp can prove that NACA had calculated the cg position correctly, according to early Spitfire cg data charts, the report needs to be viewed with some suspicion.

Originally Posted by Crumpp

Now let's get back to the NACA report so there is a better understanding of the issue.

We will look at a condition of flight essential to a dogfighter. The ability to make abrupt turns.

The pilot must be able to precisely control the amount of acceleration he loads on the aircraft.
Doing that in an early Mark Spitfire was difficult and something only a skillful pilot could perform.

Where did you get this nonsense? Show me accounts of even trainee pilots who found manoeuvring the early marks of Spitfire difficult - I repeat Supermarine's Chief Test Pilot Jeffrey Quill stated categorically that there was no problem with the longitudinal stability of early Mk I & II Spitfires.