Mezue ahịrịokwu na-esonụ: N'afọ 1941, ọ banyere n'òtù ndị agha ụgbọelu Royal Air Force, ka ọ na-erule oge oyi, ọ na-esozi ndị ọrụ afọ ofufo ndị America, bụ́ ndị nọ n'òtù ụgbọelu No. 121 (Eagle) Squadron, alụ ọgụ. Onye ọkwọ ụgbọelu Mahon merụrụ atọ German na-alụ ọgụ na abụọ Focke-Wulf Fw 190s na Eprel na a Messerschmitt Bf 109 na May, tupu ya akara mbụ ya kwupụtara mmeri nke abụọ Fw 190s, gburu na Saint-Omer ebe, na June 8, 1942. N'abalị iri atọ na otu nke ọnwa Julaị, o gburu Fw 190 abụọ ọzọ n'ebe Berck-Sur-Mer ma bụrụ onye a ma ama mgbe ọ na-ekpuchi
Ndị agha commando wakporo Dieppe n'August 19, 1942, nke bụ nke ugboro 98 ọ na-aga ịkwọ ụgbọelu. N'elekere 08:30, na-efe ụgbọelu Spitfire Vb ya, nke a na-akpọ "Barry", Mahon gburu otu Fw 190 na Fw 190 ọzọ tupu ụgbọelu ya adaa ma a manyere ya ịpụ n'ụgbọelu ahụ na-ere ọkụ. Mgbe o rutere n'oké osimiri, a dọọrọ ya n'agha. Ọ bụ ezie na Mahon gbara akwụkwọ maka igbu ndị Germany abụọ n'ụbọchị ahụ, e nyere ya otuto maka otu mgbe agha ahụ gasịrị. N'ihi ya, n'ihi ihe ndekọ ndekọ nke mmadụ ise a kwadoro, mmadụ abụọ nwere ike na mmadụ atọ mebiri emebi, Mahon natara British Distinguished Flying Cross na 1985.