Hypoxia : the silent operator in helicopter flying Wg Cdr P

Somewhere in the Eastern Sector an unpressurised helicopter took off from a fighter base for a hill training sortie. The pilot was tasked to undertake helipad-training sortie at an altitude of around 18,900 ft. The helicopter carried our three circuit approaches of a helipad at an altitude of around 16,000 ft and then proceeded to the second helipad located at 18,900 ft. Two uneventful approaches terminating in a hover were carried out successfully. During the third approach, at short finals, the ground speed and / or ROD was suddenly perceived to be high for which the pilot took brisk corrective actions resulting in an over pitching with sudden increase in ROD. Further corrective actions on the part of the pilot led to a port side drift of the helicopter. The helicopter impacted the ground on the right skid and toppled to the left. The crew and passenger came out safely. Strip examination of the aero engine and main gearbox did not reveal any malfunction. The accident was labeled as a human error accident. The possible underlying role of hypoxia is discussed in the article.