Thanks Mike.
Admittedly the creation of a hard runway rather limited the choice of landing direction (not entirely a good thing in taildragger days) but would allow the display of a specific heading. However I am asking if the display of a runway designator came about almost immediately or was it something that evolved later?
By 1944 the RAF had a good number of hard surfaced aerodromes but the data sheets I have still show a QDM rather than a specific ID. I'm still trying to work out if it's the paperwork that misses out the information or whether QDM was actually used until runway ID's appeared at a later stage.
Were runway designators a post war development or can readers recall their use during the war?
jb