Lancaster I and III production July 1944 to end of production was 2,777, with a rate of 200 and 300 per month July 1944 to March 1945 (average 250 per month), versus 321 Rose turrets made and if the turrets were restricted to 1 Group then it was probably a post manufacture fitting, either at a maintenance unit or at the squadron that received it. Presumably the change had a modification number. Maybe try finding a photograph with the turret fitted where the serial number is shown then look up the aircraft card to see if the change is noted. After that comes the 1 Group squadron histories. The 180 mark VII, fitted with the FN.82 rear turret, were built between April and December 1945.
According to the Ministry of Aircraft Production aircraft turrets were built by Parnell Aircraft 1939 to end 1945, Brockhouse 1939 to end 1945, Lucas Birmingham Q4/39 to end 1945, Lucas Cwmbran Q3/41 to end 1945, Diamler Q2/41 to end 1945, Rose Brothers Q3/44 to end 1945, Boulton Paul Q4/44 to end 1945 and Arrow Aircraft Q2 and Q3/44.
Rear Turrets for Lancasters. Program is planned production for the month. "in FN.120" means the report does not split the program between the 120 and 121. The FN.120 and 121 were in production for several aircraft types each of whom have separate entries in the production reports.
| Month | Type | Production | Program | Month | Type | Production | Program |
Jul-44 | FN.120/121 | 313 | 340 | Apr-45 | FN.82 | 75 | 85 |
Jul-44 | R.1 | 10 | 0 | Apr-45 | FN.120 | 65 | 0 |
Aug-44 | FN.120 | 277 | 350 | Apr-45 | FN.121 | 228 | 250 |
Aug-44 | FN.121 | 3 | in FN.120 | Apr-45 | R.2 Mark I | 17 | 60 |
Aug-44 | R.2 | 8 | 0 | May-45 | FN.82 | 62 | 115 |
Sep-44 | FN.120 | 269 | 400 | May-45 | FN.120 | 52 | 0 |
Sep-44 | FN.121 | 102 | in FN.120 | May-45 | FN.121 | 160 | 250 |
Sep-44 | R.2 | 17 | 0 | May-45 | R.2 Mark I | 27 | 60 |
Oct-44 | FN.120 | 160 | 430 | Jun-45 | FN.82 | 86 | 150 |
Oct-44 | FN.121 | 151 | in FN.120 | Jun-45 | FN.120 | 2 | 0 |
Oct-44 | R.2 | 14 | 0 | Jun-45 | FN.121 | 130 | 85 |
Nov-44 | FN.120 | 178 | 430 | Jun-45 | R.2 Mark I | 27 | 60 |
Nov-44 | FN.121 | 165 | in FN.120 | Jul-45 | FN.82 | 75 | 165 |
Nov-44 | R.2 | 12 | 0 | Jul-45 | FN.121 | 59 | 0 |
Dec-44 | FN.82 | 2 | 15 | Jul-45 | R.2 Mark I | 35 | 60 |
Dec-44 | FN.120 | 113 | 0 | Aug-45 | FN.82 | 87 | 190 |
Dec-44 | FN.121 | 197 | 228 | Aug-45 | FN.121 | 8 | 0 |
Dec-44 | R.2 | 14 | 20 | Aug-45 | R.2 Mark I | 13 | 60 |
Jan-45 | FN.82 | 28 | 26 | Sep-45 | FN.82 | 42 | 153 |
Jan-45 | FN.120 | 85 | 0 | Sep-45 | R.2 Mark I | 23 | 0 |
Jan-45 | FN.121 | 236 | 210 | Oct-45 | FN.82 | 69 | 117 |
Jan-45 | R.2 | 27 | 30 | Oct-45 | R.2 Mark I | 21 | 0 |
Feb-45 | FN.82 | 40 | 40 | Nov-45 | FN.82 | 80 | 0 |
Feb-45 | FN.120 | 95 | 0 | Nov-45 | R.2 Mark I | 6 | 0 |
Feb-45 | FN.121 | 164 | 217 | | | | |
Feb-45 | R.2 | 24 | 30 | 1944 | Rose | 75 | total |
Mar-45 | FN.82 | 50 | 60 | 1945 | Rose | 246 | total |
Mar-45 | FN.120 | 97 | 0 | | | | |
Mar-45 | FN.121 | 250 | 250 | | | | |
Mar-45 | R.2 Mark I | 26 | 40 | | | | |
July 1944 FN.50 and FN.150 mid upper turrets in production. FN.120 and 121 also for Lancaster IV and V = Lincoln
September 1944, FN.120 and 121 also for Lincoln (no more Lancaster IV and V)
October 1944, FN.121 only also for Lincoln
December 1944 FN.50 plus FN.150 mark I and IV mid upper turrets in production.
March 1945 FN.121 production for Lancaster only, FN.150 mid upper turret production no mark numbers given.
March 1945, production reported of 250 CE 23A mid upper turrets for Lancasters.
May 1945, end FN.150 mid upper turrets
July 1945, end FN.50 mid upper turrets
October 1945, R.2 Mark I turret now for Lincoln
November 1945, end of Rose Turret production.