Top Causes for Fatal and Non-Fatal Accidents in Helicopter Operations

Abstract

We identify and compare the top causes for fatal and non-fatal helicopter accidents using historical accident data. We compare the causes for fatal and non-fatal accidents and identify the causes that are most likely to lead to both fatal and non-fatal accidents, the causes that are more likely to lead to fatal accidents than non-fatal accidents, and the causes that are more likely to lead to non-fatal accidents than fatal accidents. Accidents that had serious, minor, and no injuries were grouped as non-fatal accidents. We analyzed 5051 helicopter accidents between 1982 and 2008, and found that personal use, instructional flight, and aerial application missions accounted for 50.1% of the accidents. Poor weather condition was the top cause in 17.6% of fatal personal use accidents. Poor weather accidents generally occurred while operating in fog (20.4%), low ceiling (18.5%), strong tailwinds (11.1%), or rain (9.3%). Failure to maintain physical clearance (24.4%) and collision with objects were equally likely in fatal aerial application accidents. Some of the top causes appeared across mission types. Inclement weather condition was among the top causes not just during personal use, but also for instructional flights, appearing at least once in 15.3% of fatal and 12.8% of non-fatal accidents. Collision with objects was another one of the top common causes appearing across all three mission-types. By identifying the most frequent causes across different injury levels and mission types, we can leverage accident information from various sources (e.g., detailed accident reports, flight data records) to improve rotorcraft safety.