He was commissioned in the RAFVR, converted to Blenheims and joined No 235 Squadron on 5 August 1940. This was one of the Coastal Command squadrons that flew under Fighter Command control during the Battle of Britain. He shared in destroying a He 59 off Cherbourg on 8 October.
Gonay had a spell as an instructor. In the summer of 1941 he joined No 131 Squadron, a Spitfire unit. In the following month he was awarded the Belgian Croix de Guerre. In October he was one of the squadron pilots who formed No 350 Squadron. He then moved to No 232 Squadron, was awarded the French Croix de Guerre for his involvement in the Dieppe operation and was appointed to command No 129 Squadron and then No 263 Squadron.
On 14 June 1944, Gonay’s Typhoon was hit by flak while attacking two ships off Jersey. His aircraft crashed into outbuildings at a house in St Ouen, Jersey, and the house was destroyed in the subsequent fire. Two families lived in the house; one was absent, but a mother and her two children escaped as the aircraft approached.
Gonay was buried in the St Helier War Cemetery. After the war his remains were exhumed and reburied in the Brussels-Evere Military Cemetery.
In 2018 a new house stands on the site, but a barn survives from the time of the crash. A nearby road is named Rue Henri Gonay.
