 Johnson 's old injury continued to trouble him and he found flying high performance aircraft like the Spitfire extremely painful . RAF medics gave him two options ; he could have an operation that would correct the problem , but this meant he would miss the Battle of Britain , or becoming a training instructor flying the light Tiger Moth . Johnson opted for the operation . He had hoped for discreet treatment , but word soon reached the CO , and Johnson was taken off flying duties and sent to the RAF Hospital at Rauceby . He did not return to the squadron until 28 December 1940 . CO Burton took Johnson up for a test flight on 31 December 1940 in Miles Magister L8151 . After the 45 @-@ minute flight , Johnson 's fitness to fly was approved . 
