There are many places to start the searching. Being WWII, it should be fairly easy to track down. Most regiments or squadrons did a photograph pretty much annually, in the case of the RAF and it's commonwealth allies, this included as a rule all Officers, NCO's, Pilots, Ground Crew and Armourers and Mechanics / Engineers. On some occasions even peripheral staff.

I would suggest as a first port of call (if you haven't already) the RAF website, they have a fairly extensive site. If you find nothing there, don't give up and use the contact us button to ask questions.

Try to find out if there is a 312 squadron old boys club, or any re-union either past or present, these guys tended to stick together or keep in touch after the war.

Then you have the records office at Kew and the Imperial War Museum to investigate.

I am currently starting a project to find out the details of the WWI dead for my home town of Crowborough, and it takes an awful lot of digging around just to get even started, made even harder due to the fact that lots of records were destroyed in the Blitz! But stick with it, it will be well worth while when it all sorts out.

Another point of call is Ancestry.com who have started war trails, they might be useful.

Good luck and keep us informed of anything you find.