Patterson’s regimental number was J/93274 and he was assigned to the Royal Canadian Air Force (RCAF) with the rank of Pilot Officer. His training took place from June 17, 1943, to October 24, 1943. He was trained in Ottawa, Quebec, Toronto, Lachine, and Mont Joli, before going to Halifax to be sent to the war front. During this time, he was promoted to sergeant. 

A close call with death happened on February 2, 1944. Patterson and his crew were in the air for five hours, returning to the base at Castle Donington (now East Midlands Airport), when the port engine caught fire. The pilot announced a landing, but the landing was faulty and before nearly touching down, there was a right hand turn (most likely due to a restricted run out). The aircraft turned over on its side, crashing and bursting into flames. Patterson received a serious cut on his head, as well as a concussion, but remained conscious. He was taken to Wymeswold Hospital for treatment before being transferred to Rauceby. He was lucky, considering all five of his crewmates died in that crash.

Patterson died on December 12, 1944, after two years of service. His aircraft, consisting of 7 crew members, crashed, bursting into flames upon making contact with the ground. The pilot (R.C. Veitch) and another air gunner (L. Hunt) were killed along with J.R. Patterson. The crew was on a mission to pursue air raid operations against Essen. All three soldiers were temporarily buried in Duesseldorf, Germany. However, they were later relocated to a British military cemetery called Reichswald Forest War Cemetery. Although their bodies were never found, there are still gravestones standing in their memory. The specifics as to where Patterson was buried are plot V III, row D, grave 1.  

Un incident s’est produit pendant son service, au retour à la base de Castle Donington le 2 février 1944. Le moteur de son avion a soudainement pris feu en vol avec John Richard Patterson et son équipe à bord. En essayant d'atterrir, le véhicule s’est renversé et s’est écrasé à Wymeswold. Patterson est resté conscient pendant tout l'événement et a subi une commotion cérébrale et une coupure sérieuse sur sa tête. Il a été libéré de l'hôpital et est courageusement retourné en service peu de temps après. 

'If we do preserve it, we honour them, and when we in our turn pass on, we will know that behind us lives a generation of free men and of free women to be the keepers of this great heritage of ours - Canada.'

- Ian A. McPhee, former student at GCI, 1937.