2 "gotchas" here - the aircraft serials for "the squadron's" aircraft may not be sequential, so just because they had DB201 does not mean that they had any, never mind all, of DB189 to DB200 or DB202 to DB212. Also, the individual aircraft codes are semi-random. For example, on "Operation Chastise", the squadron commander, Guy Gibson, flew AJ-G, flight commander "Dinghy" Young flew AJ-A. (Details cross-checked on Wikipedia)