René Mouchotte qualified as a military pilot in 1937 and was mobilised in September 1939. He joined the Avord fighter training school as a trainee instructor, then in May 1940, with his friend Guérin, he was sent to the fighter training centre at Oran. On 30th June, against direct orders, Mouchotte and eight of his comrades flew to Gibraltar in two aircraft and arrived in Liverpool on 13th July 1940, in time to watch the first 14th July review presided over by General de Gaulle, in London. After training at Old Sarum, near Salisbury, at the School of Army Cooperation, he joined 6 Operational Training Unit at Sutton Bridge, for training as a Hawker Hurricane fighter pilot. At the beginning of October, he left with 615 squadron for Northolt, in the western suburbs of London.
On 11th October, René Mouchotte, carried out his first operational sortie and spotted the French coast. On 15th December 1940, 615 squadron returned to its base at Kenley, south of London. On 4th March, René Mouchotte was awarded temporary command of a Flight. On 26th August he shot down a Junkers 88. On 10th November 1941, René Mouchotte joined Turnhouse RAF base, where first fighter group n° 2 "île de France" (340 squadron) was undergoing training. When Flying Officer Philippe de Scitivaux took command of the Group in February 1942, René Mouchotte replaced him as head of A Flight "Paris". He was promoted to Captain on 15th March 1942. General de Gaulle awarded him the Croix de la Libération, on 14th July 1942 and on 1st September he received the Distinguished Flying Cross. He was given the command of 65 squadron, then went on to lead Fighter Group n° 1 "Alsace" which, following a tour of duty in the Middle East, was posted back to Great Britain as 341 squadron of the RAF. On 17th March 1943, 341 was considered fit to serve with 11 Group, where there was a great deal of enemy activity and returned to base at Biggin Hill. On 15th May 1943, the Biggin Hill wing, with 998 victories in the air, took off for a protection mission. "Alsace" was flying with 611 squadron, commanded by Squadron-Leader Charles. The wing was attacked over the Pas-de-Calais by a large formation of Fw 190's. Charles shot one down, bringing the wing's score to 999, before Mouchotte brought up the 1,000th kill. Commandant René Mouchotte's will read as follows: "If fate only allows me a short career as Commandant, I will thank heaven that I was able to give my life for the Liberation of France. Tell my mother that I was always happy and grateful that I had the opportunity to serve God, my Country and those I love and that, whatever happens, I will always be by her side." The last lines of his flight log said: "Sorties continue at a terrible rate. My record is 140. My fatigue is merciless and I can feel my nerves breaking. I have an unbearable need for rest. I haven't taken a week's leave in over two years. Always on alert to fly. I am worn out, but tomorrow ...I will be off until 26th August. He would never come back, shot down over Belgium. He amassed 1,748 flying hours including 408 on 382 war sorties. He "Died for France" on a mission in September 1943.