Basically, the RAF fighter guys had the same problem the Luftwaffe guys had during the Battle of Britain - short range, (comparatively) long distance to travel, leading to short loiter time over the beaches. Add to that the fact that much combat occurred at high level, out of sight of the troops on the ground, and you have the classic conditions for "where were the Brylcreem boys?" questions.
One point for research may be the number of RAF pilots shot down/interred in France during May/June 1940 - try the Commonwealth War Graves Commission.
Tocsin (whose dad escaped from the beach...)