PMedMoe said:
Well, according to
Wikipedia:
Considering it was around 1943 and there was a war going on, the aircrew and medical standards may have been lower than they are now.
Perhaps his hearing loss was not as profound during the war? Apparently, the war ended before he was sent overseas.
In spite of the pathetic chances of survival, there was never a shortage of volunteers for aircrew. There is a book on the subject: "Selected for Aircrew". One of the attractions may have been an immediate promotion to Flight Sergeant, or a commission. They also lived in relative peace and comfort when not flying. They were well treated on the ground.
Another book on the subject of RCAF aircrew selection: "The Cream of the Crop: Canadian Aircrew, 1939-1945":
http://www.amazon.ca/Cream-Crop-Canadian-Aircrew-1939-1945/dp/0773513981
"describes the development of a uniquely Canadian selection system that attempted to match the aptitudes of aircrew candidates to the duties they would perform and the evolution of the RCAF's training program from a haphazard system with enormous attrition to one that became the model for many modern systems."
I viewed the complete personnel files of five RCAF WW2 aircrew in Ottawa and the selection process seemed very thorough to me.
I listened to this 1991 radio interview: "Leslie and Erik Nielsen laugh it up". They describe how throughout their careers that people were frequently confused as to who was who:
http://archives.cbc.ca/society/family/clips/15497/