From AP3024, Flying Control in the Royal Air Force (reprint Aug ’44), Section 7, Regulations for the Local Control of Aircraft:-

Para 23. GENERAL REGULATIONS

(III) When flying in the vicinity of an airfield and/or awaiting permission to land, aircraft are to fly on left-hand circuits unless special local regulations are in force. Reference is to be made to the appropriate Confidential Document for such regulations.

I’m sure I’ve read about such local regs in Bomber country where circuits must have overlapped due to the proximity of ‘dromes.

There are also instructions about the “patter” to be used between individual aircraft and control which follows the advice quoted above but using 500 ft. seperation, which seems to make sense if you consider an airfield with 40 returning bombers!