It's pretty interesting, to me at least, because RCAF Bomber Command aircrew were under RAF authority.
The crew's personnel files were in Ottawa. We got to see those.
But, their operational records were in the U.K. We had to hire a researcher.
The units of Bomber Command were in a uniquely favorable position to produce a reliable documentary record of their operations. A far-sighted Air Ministry had ordered that standard forms 540 and 541 were to be completed for every opeational flight by every single aircraft. The aircraft's serial number, names of it crew, its bomb load, and take of time were all recorded. If the aircraft returned, its landing time and resume of the crews experiences during the flight were added. Squadrons made composite reports, Groups consildated them and Bomber Command HQ produced an overall report of every raid. Because all the links in the chain were home-based, none of the records were lost to enemy action.