ATSB Study Finds Turboprop Engines Safe, Reliable

 - June 25, 2018, 11:51 AM

A review of powerplant‑related occurrences reported to the Australian Transportation Safety Bureau (ATSB) showed that there were 417 events involving turboprop aircraft between 2012 and 2016, or 83 per year on average. With more than 1.4 million flight hours for these aircraft over the five-year study period, this equates to approximately 2.2 occurrences every 10,000 flight hours. None resulted in serious injuries or fatalities.

Ninety-six percent were classified as “low risk” occurrences with a no accident outcome, but there were four listed as “medium risk” and three as “high risk.” The latter all involved engine failures or malfunctions with forced or precautionary landings in single‑engine Cessna 208 Caravans.

The two occurrences in the set that resulted in any injury (both minor) were the result of engine failure or malfunctions and collision with terrain in agricultural operations. Five classified as accidents all involved aerial work operations, four in agriculture, and one in emergency medical services.

One aircraft type—the Allison 501-powered Convair 580—was found to have a rate of 13.9 engine occurrences per 10,000 flight hours, more than double the rate of any other turboprop aircraft. However, with only four occurrences between 2012 and 2015, the high rate is due to “relatively very low flight hours” for this aircraft. All four of these occurrences were classified as non-serious incidents and as such were rated “low risk.”