For the second year in a row, U.S. Federal Aviation Regulations Part 121 and Part 135 scheduled (commuter) operations resulted in no fatalities, according to preliminary data from the U.S. National Transportation Safety Board (NTSB).1 Part 135 on-demand (air taxi) flights, however, had the most fatal accidents and fatalities since 2008.
The accident rates for scheduled Part 121 flights and scheduled Part 135 flights favored Part 121 flights. The former had a rate of 0.314 accidents per 100,000 departures, the latter 0.714 accidents per 100,000 departures, or 2.3 times the Part 121 rate. The contrast based on rates per 100,000 flight hours was even starker: 0.162 for Part 121 versus 1.303 for commuter flights, making the commuter rate eight times that for Part 121 air carriers.
Departure information was unavailable for Part 135 on-demand operations, but the rate for all accidents per 100,000 flight hours showed nearly the same discre…
