The H-34 pilot was the lead in a trailing formation of seven or eight helicopters. When he realized what was happening he ordered the other helicopters to come to a hover and do a 180. Those pilots had visual contact with the canyon walls and the canyon floor. They got out. Pulling collective up to his armpits might have worked but what if he translated sideways and hit the canyon wall. It was assumed in the accident investigation that the pilot in losing spatial orientation suffered from vertigo and any action would result in disaster.
Shortly thereafter the Army installed ASE on their H-34s and the ASE when rigged was nulled out to reflect a level condition when the helicopter was hanging tail down and to the left so even if the instruments indicated a climb to the left the ASE would indicate level flight. This may or may not have helped the subject pilot.
