Danny,
'my' Observer flew Ops to the usual places in the Whitley until April 1942 when 78 appears to have converted to the Halifax. He flies on Ops on the Halifax until Jan 1943 when he becomes an instructor at 1658 CU at Riccall.
Six months later he is back on Ops with 78 Sqn and is on amongst others the Peenemunde raid. At some stage he must have been commissioned (I do not have his Record of Service) as by Nov 1944 his logbook has him as the 'A' Flight Commander on 78. By the start of 1945 he is a squadron commander with the DFC. All of this in 4 Group. Not bad for HO Observer. But 4 Group had a habit of appointing non pilots as Sqn Commanders. Witness W/C 'Lofty' Lowe who was OC 77 Sqn in 1944. He was an Air Gunner. More later. Trust me we are on track towards Danny's India with only minor deviations !