Squadrons had an established strength of 12 aircraft (with spares to allow for repairs) and between 16 and 26 pilots to allow for rotation, leave, illness and injury. Squadrons were divided into two Flights ('A' and 'B'), each Flight was divided into two Sections of three aircraft (colour coded as red, blue, yellow and green). When on duty a pilot would be assigned to a Section and allocated a specific aircraft that they'd then check over:

"Dispersal pen and my Spitfire. I pause and look at her. A long shapely nose, not exactly arrogant, but, nevertheless, daring anyone to take a swing at it. (...) I walk forward and hang my parachute on the port wing for a quick getaway; you can easily put it on whilst the engine is being started (...) Now up to the cockpit. Up on to the wing and step in. I hang my helmet on the stick and plug in the R/T lead and oxygen tube. At the same time, I check the bottle content: full. Fuel? Press the fuel gauge button,real full also. Now brake pressure. OK, that's fine. Trim? Let's adjust it now and then it's done with. Full rudder bias to help with the swing on take-off, elevators one degree nose heavy, that's good. Airscrew, full fine pitch. That's about it, then, ready to scramble when the time comes. Bound to come sometime. It'll be a miracle if we get through to midday without one." (Geoff Wellum, First Light)

ideally personnel and their aircraft remained as constant as possible as they got used to working together but that wasn't always possible. Logbooks record which aircraft were flown; F/O J J O'Meara of 64 Squadron, for example, flew Spitfires coded 'B', 'D', 'E' and 'K' in August 1940, whereas F/Lt E H Thomas of 222 Squadron mostly flew Spitfire 'ZD A' in October.

Nose art was less common in the RAF than the USAAF, not officially sanctioned, but there were instances of personalised aircraft, such as a shamrock painted on Brendan 'Paddy' Finucane's Spitfire or a wasp on Arthur Clowes' Hurricane.