Night conditions constrain the operations of a helicopter. Helicopter crews thatfly at night have limited landing possibilities in times of emergency and sufferfrom limited visual cues during operations. This study compares the underlyingcauses and factors that differentiate daytime and nighttime helicopteraccidents. From the US National Transportation and Safety Board (NTSB) onlinedatabase, 4,755 helicopter accidents were selected for which the characteristicsof day and night flights were compared. The number of fatal accidents occurringat night was significantly higher than during the daytime(χ2 = 95.04, df = 1,p < .001). Helicopter accidents that occur at nightalso show significantly fewer engine failures and autorotations butsignificantly more weather-related causes. The relative absence of enginefailures at night is partly explained by the absence of specific helicopteroperations. The combination of night flights and adverse weather conditions isshown to be particularly fatal in accidents. It is concluded that pilots requiremore conservative planning particularly in the vicinity of adverse weathersystems.
Aviation Psychology and Applied Human Factors – American Psychological Association
Published: Jan 1, 2011