Page "Aerodynamics" Paragraph 24

A similar problem affected some models of the Supermarine Spitfire.

At high speeds the ailerons could apply more torque than the Spitfire's thin wings could handle, and the entire wing would twist in the opposite direction.

This meant that the plane would roll in the direction opposite to that which the pilot intended, and led to a number of accidents.

Earlier models weren't fast enough for this to be a problem, and so it wasn't noticed until later model Spitfires like the Mk. IX started to appear.

This was mitigated by adding considerable torsional rigidity to the wings, and was wholly cured when the Mk. XIV was introduced.