United Kingdom Military Aircraft Serials - A1 To Z9999

A1 To Z9999

By 1916 the first sequence had reached 10000 (allocated to a Royal Aircraft Factory BE.2, built by Blackburn Aircraft) and it was decided to start an alpha-numeric system from A1 (allocated to a Royal Aircraft Factory BE.2d) to A9999 then starting again at B1. The letters A, B, C, D, E, F, H, and J were allocated to the Royal Flying Corps and N1 to N9999 and S1 to S9999 to the Royal Naval Air Service. When the sequence reached the prefix K it was decided to start at K1000 for all subsequent letters instead of K1.

Although the N and S series had earlier been used by RNAS aircraft, the sequence N1000 to N9999 was again used by the Air Ministry for both RAF and RN aircraft. The 'Naval' S sequence had reached only S1865, a Fairey IIIF, but when R9999 was reached in 1939, the next serial allocations did not run on from that point, but instead commenced at T1000.

From 1937 not all aircraft serials were allocated, in order to hide the true number of aircraft in production and service. Gaps in the serial number sequence were sometimes referred to as "blackout blocks". The first example of this practice was an early 1937 order for 200 Avro Manchester bombers which were allotted the serials L7276-7325, L7373-7402, L7415-7434, L7453-7497, L7515-7549 and L7565-7584, covering a range of 309 possible serial numbers, and thus possibly leading an enemy to over-estimate British military aircraft strength.