314918 John Martin (barechested) and another identified member of No 9 Squadron, RAAF, tracking ...

314918 John Martin (barechested) and another identified member of No 9 Squadron, RAAF, tracking the main rotar blade of an Iroquois UH-1B helicopter. The rotor blades were marked with red and yellow chinagraph pencils, and the upright steel pole was pre-positioned prior to the helicopter starting its engine. The pole was then turned around so that the canvas 'flag' attached to the end was nicked by the rotor blades leaving a mark on the canvas, which was then checked to ensure that the blades were flying in track. 34528 Cpl Douglas 'Jock' Bowie (far right) is checking that the blades will actually nick the canvas flag on the pole prior to it being turned around. Also identified is 1889 Peter Steiner (standing next to the helicopter), who is probably completing instrument check while the aircraft's engine is running. Note the red dot on the door of the helicopter. In the background is an Australian Caribou.