Even stranger. The USAAF Serial number 41-24364 B17-F was once a Royal Air Force B-17 serial number FA 679? to be confirmed by photographic evidence though...
"Air Ministry Serials Applied to USAAF B-17Fs (pages 30 to 32 and 151)
Britain ordered 300 B-17s, ‘nominally B-17Es’, in June 1941 under Defense Aid contract DA-16. They were allocated Air Ministry serials FA675 to FA823 (149 serials) and FH467 to FH617 (151 serials) but in the end none of these serials were applied to RAF-bound B-17Es. At least some of the 20 serials from the beginning of the first series, FA675 to FA694, are known to have been applied to early B-17Fs subsequently operated by the USAAF while the 19 B-17Fs delivered to Britain were allocated the next serials, FA695 to FA713. The rest of the FA serials, FA714 to FA823, and all the FH serials allocated to B-17s were never used.
No records for the application of these Air Ministry serials appear to have survived and there is no indication on their Individual Aircraft Record Cards, as there is for B-17Es assigned to Britain, that these B-17Fs were ever formerly intended for Britain.
One possible explanation for the application of the Air Ministry serials is that Boeing and Air Ministry personnel at Seattle initially understood that B-17Fs would follow the 45 B-17Es delivered to Britain after production of the latter ended. Boeing then applied the first available FA serials to up to 20 early B-17Fs, leaving FL465 to FL502 from the FL449 to FL502 allocation previously applied to B-17Es unused.
More photographs of the 20 B-17Fs have recently come to hand and an analysis of available images strongly suggests that all 20 Air Ministry serials FA675 to FA694 were applied in sequence with a contiguous block of USAAF serials as follows. Interestingly, the 19 Air Ministry serial numbers applied to smaller blocks of B-17Fs that were delivered to Britain ran in sequence with their respective USAAF serials.
USAAF Serials
41-24360 – 41-24379 Air Ministry Serials FA675 – FA694 (20)
Notes Confirmed match-up
41-24360 – 41-24362 FA675 – FA677 (3)
Matchups unconfirmed
41-24363 FA678 Photographic confirmation
41-24364 – 41-24367 FA679 – FA682 (4) Matchups unconfirmed41-24368 FA683 Photographic confirmation
41-24369 FA684 Photographic confirmation
41-24370 FA685 Photograph indicates this aircraft had an over-painted Air Ministry serial
41-24371 – 41-24375 FA686 – FA690 (5) Matchups unconfirmed
41-24376 FA691 Photographic confirmation
41-24377 – 41-24379 FA692 – FA694 (3) Matchups unconfirmed
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