602 Squadron was transferred to Kenley, operating with No. 452 and 485 Squadrons as part of the fighter wing flying from Kenley. The Kenley wing, as it was known, was to conduct operations over northern France, escorting bombers and carrying out fighter sweeps. Later that month, his rank of flight lieutenant was made substantive, and at the beginning of August, Deere took over the squadron while its regular commander was in hospital. The same day, he claimed an Bf 109 shot down. Although officially credited with this kill, his biographer, Richard Smith, considers it a possibility that this was in fact a friendly fire incident, and the aircraft destroyed may have been a Hawker Hurricane of No. 242 Squadron. On a sweep over Béthune, on 9 August 1941, Deere, unable to see them go down, claimed three Bf 109s as damaged. A fellow pilot noted Deere had a high level of integrity when it came to claiming enemy aircraft shot down. A few days later, while escorting Handley Page Hampden bombers near Lille, his Spitfire was damaged by a Bf 109 that had surprised him. Enemy cannon tore a large hole in his wing and there were over 30 bullet holes through the fuselage. Despite leaking glycol, he was able to cross the English Channel and land at Manston airfield. Deere claimed two more Bf 109s as damaged between September and November 1941, and his rank of flight lieutenant was made permanent. By this time, high losses among fighter pilots and bomber crews saw the RAF reduce its offensive operations to Belgium and France over the winter months. In January 1942, No. 602 Squadron was taken over by Squadron Leader Brendan Finucane and Deere was sent on a lecturing and public relations trip to America. Arriving in early March, he taught American pilots fighter tactics learnt in the Battle of Britain and the later fighting over France. He was also able to fly American aircraft. After six weeks in the United States, he returned to England. He found that he had been assigned to a staff post in the Far East but preferred to remain in Europe. He arranged a meeting with the commander of No. 11 Group, Air Vice-Marshal Trafford Leigh-Mallory, who gave him command of No. 403 Squadron, of the Royal Canadian Air Force, instead. He took up his command, based at North Weald in Essex, on 30