Hugh
Can't add much to the information provided by Liz but the following may help round things off:
Claude Alward RIDLEY, No 60 Sqn, got the MC as per the Gazette of 16 May 1916, was forced down by engine failure behind the German lines on 3 August 1916 during the course of a spy-dropping mission and received the DSO as per the Gazette of 14 November 1916. An account of Ridley's activities after his forced landing appears in
The Sky Their Battlefield, p 100.
Major (Acting Lieutenant-Colonel) Paul Copeland MALTBY DSO (R Welsh Fus) received the AFC per the London Gazette of 3 June 1919;
Lieutenant-Colonel Richard Edmund Charles PEIRSE DSO received the AFC per the London Gazette of 1 January 1919;
Squadron Leader (Acting Wing Commander) Lancelot TOMKINSON received the AFC as per the London Gazette of 10 October 1919.
The details are as shown in the Gazette of the relavant date (although I cannot find my copy of the 1 January 1919 entries to confirm whether Pierse's rank was substantive or acting, I'll see if I can sort this out if you require this degree of detail).
I have a scribbled note that the awards appearing in the Gazette of 10 October 1919 were the first to use the new RAF ranks and were presumably for post-war service since other entries in this Gazette are for "services rendered in connection with the War" and quote the old RFC/RAF rank.
As the AFC was awarded without citation, there is no simple way of determining the reason for these awards, other than being "for an act or acts of valour, courage or devotion to duty performed whilst flying though not in active operations against the enemy."
Graeme