 0n 19 August 1940 , Johnson flew a Spitfire for the first time . Over the next weeks he practised handling , formation flying , attacks , battle climbs , aerobatics and dogfighting . During his training flights , he stalled and crashed a Spitfire . Johnson had his harness straps on too loose , and wrenched his shoulders – revealing that his earlier rugby injury had not healed properly . The Spitfire did a ground loop , ripping off one of the undercarriage legs and forcing the other up through the port main plane . The commanding officer excused Johnson , for the " short airfield " was difficult to land on for an inexperienced pilot . Johnson got the impression , however , that he would be watched closely , and felt that if he made another mistake , he would be " certainly washed out " . Johnson tried to pack the injured shoulder with wool , held in place by adhesive tape . He also tightened the straps to reduce vibrations . Johnson found he had lost his " feel " in his right hand , and it became numb . When he practised dives , the pressure also aggravated his shoulder . He often tried to fly using his left hand only , but the Spitfire would have to be handled with both hands during anything other than simple manoeuvres . Despite the difficulties with his injuries , on 28 August 1940 , the course was complete . Johnson had 205 @.@ 25 hours on operational types including 23 @.@ 50 on the Spitfire . 
