Providing the information turns out to be true and he is a wannabe. Is their a site for British wannabes? Maybe out him if he continues with this, after being proven beyond all doubt to be liar. Sorry state of affairs when people publicly try to take the Honour of the men and women who actually were their doing the amazing job of the generations of those days. Some how I hope it turns out to be true. How many enemy planes did a Brit have to shoot down to be regarded as a ACE?
The term 'ace' has never been officially recognised RAF, RAAF etc. However, unofficially ace status is reached with 5 or more victories. As for Powell, I have contacted the newspaper presenting the (lack) of evidence. He's not the first one to be caught out, and probably won't be the last. However, if he is claiming the DFC without being awarded it then he will be in deep do-do in America as they intend to make that a criminal offence.
Same as anyone else - five. However, it wasn't as 'officially' recognised as the American side of things. The RAF did not support the view and many pilots during and after the war actually thought the term related to those very high scorers who were household names. EDIT: LOL, what Kyt said. I've seen some correlation with five victories earning a DFC but can 't place them now.
I have also made contact to the reporter and ask that he confirm details. If there is a mix up with the DFC being Gazetted and I hope it is we may receive a reply.