During the Second World War, Chitham served in the Army, and after demobilisation, studied medicine. He qualified in 1953, and enlisted in the RCAF shortly after.

Chitham was Station Medical Officer at RCAF Station Grostenquin, north-eastern France. As two CF100's were circling above the base waiting to land, they collided, and one of the engines, covered in burning fuel, landed in the corridor outside Chitham's office.

His office went up in flames, and Chitham was trapped by his desk. He managed to push his desk off, and forced his way through the still burning pieces of ceiling hanging down to get outside.

Having put out the fire on his clothes by rolling on the ground, he looked at the burning building and saw the fire was not far from the nursery. Despite struggling with control of his arm, he made his way back into the hospital and up to the nursery. He instructed a passing aircraftsman to start moving the cribs further down the corridor, and to disconnect the incubators from their oxygen cylinders and move them as well. He did the same to the padre who arrived, who instead took him to a undamaged barrack block, then left to get help.
While waiting for treatment, Chitham got up having realised more problems. He found himself unable to pick up a phone, so found a school teacher in the building who passed his messages to HQ Medical Services - notifying them of the fire and not to bring patients in labour - and to communication flight to get a Dakota ready to take out the wounded to be treated elsewhere.

Shortly after, his colleagues arrived to treat him and he was evacuated to the American hospital at Landstuhl. A week later, surprising everyone with his survival, he was transferred to RAF Halton, requiring a police escort.

During Chitham's treatment at QVH, McIndoe recruited him into the laboratory, and encouraged him to go back to work as a doctor once treatment was complete.

The last man to be admitted to the Guinea Pig Club.