Son of Gladys McWilliams (nee Pymer) and Capt. Claude McWilliams, a fellow soldier in the Royal Canadian Artillery. Pilot Officer McWilliams was declared missing on June 1, 1944, when his RAF 117 Squadron Dakota aircraft didn't return to India after a supply-dropping operation over Burma. He was presumed dead until September 2017 when his body was discovered inside an aircraft discovered at a crash site by hunters in remote jungle in India, near the Burma border.