663 Squadron had been formed in northern Italy on 14 August 1944, as an air observation post (AOP) unit, and was composed of Polish officers and soldiers.

The squadron was to spot for allied artillery units in that war zone.

[2] 663 Squadron was reformed as a Royal Auxiliary Air Force (RAuxAF) AOP unit on 1 July 1949, composed of Territorial Army artillery officers and soldiers.

[3] The unit was reformed as 663 Interim Aviation Squadron in October 1969 at Perham Down, Wiltshire, from 3 Flight AAC and the air troop of 15/19 Hussars and 5 Lt Regt RA.

Its allocated mission was to support army formations in the Salisbury Plain area.