The shoulder flash is the RAF Albatross - not much else to go on that I recognized - no other identifier or indicator of a Commonwealth Air Force so this appears to be a RAF Dress Uniform with the rank of LAC (Leading Aircraftsman) as indicated by the propellor sewn on the sleeve ...

I forgot one small detail - the arcs identifying Nationality were only added to the uniform when the airman was posted overseas I believe.  If that's correct it doesn't necessarily make the uniform RAF.  I 'm fairly certain the propellor was standard identifier of LAC though regardless of Nationality.  I couldn't achieve sufficent detail on enlargement to see if the brass buttons were RCAF inscribed  or not.  I'm afraid that it's pretty difficult to determine country of origin without some additional detail.  Sorry ...