Quote:
Originally Posted by JtD
This is a Spitfire V with metal covered ailerons, tested up to 300 mph. The Spitfire I/II with fabric covered ailerons are a lot worse, and at 400 mph IAS pretty much hopeless - ineffective ailerons combined with a rather flexible wing. British tests indicate a roll rate of about 12°/s at 400 mph with 50 lbs stick force for early Spitfires - in other words half a minute for a 360° roll.
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My bad -the NACA Spitfire had metal covered ailerons, I should have
absorbed the first sentence before reading the report
- still, that does not invalidate anything I said about the damping effect of the wingtips on the Spitfire's roll-rate. A report on a clipped wing Spitfire V vs standard bears this out:
It is interesting to see how small aerodynamic alterations can alter flight characteristics - the total area of the wingtips removed was 12sq ft but, because this was all outboard of the ailerons, removing the wingtips increased the aileron's effectiveness up to 25,000 feet. It probably increased the
torsional stiffness of the wings as well.
Just for interest the P-47N also showed the benefits of "clipped" wings:
09-07-2012, 01:33 AM
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