609 Squadron Spitfire Is at RAF Drem, Scotland in April 1940.
Spitfire Is of 611 (West Lancashire) squadron. During the Battle they were based at RAF Digby, Lincolnshire.

A Spitfire I in the X serial number range. The words "keep out" have been chalked beneath the cockpit glazing.

K9912 was one of the later production Spitfire Is, upon which the curved hood was standardised, and the de Havilland three-bladed variable-pitch metal propeller was introduced. This particular Spitfire served with 65 Sqn until it was struck off RAF charge in May 1940.

Spitfire I K9787, the first of a production batch of 213 aircraft delivered to the RAF between July 1938 and April 1939, went to the A&AEE and RAE before joining the PRU.