 Johnson took command of No. 144 Wing ( Canadians ) based at RAF Kenley after Christmas and they received the new Spitfire IX : the answer to the Fw 190 . After gaining a probable against a Fw 190 in February 1943 , Johnnie selected Spitfire EN398 after a 50 @-@ minute test flight on 22 March 1943 . It became his regular mount . Being a wing commander now meant his initials could be painted on the machine . His Spitfires now carried JE @-@ J. He was also allotted the call sign " Greycap " . 
