When aviation people speak of Part 135 operations, many of us naturally assume a business jet or at least turboprop is involved. So when the NTSB released 2011 accident data a few weeks ago (“Total accidents involving on-demand Part 135 operations climbed from 31 in 2010 to 50 in 2011, while fatal accidents rose from six to 16 and fatalities rose from 17 to 41.”), the numbers appeared quite unambiguously to refer to turbine-powered airplanes.
The story behind those numbers, however, is not quite as clear as the one that evolved when AIN spent time digging into the raw data used by the NTSB. The spreadsheet actually showed something quite different from what many people might have expected.
Of the 50 accidents and 41 fatalities involving Part 135 aircraft, only four actually involved turbine-powered airplanes: a Learjet 35A, an Embraer EMB-500 Phenom, a Swearingen SA227 Metroliner and a Cessna 208 Caravan. One of those, the Caravan accident, resulted in a single fatality.
Eight turbine-powered helicopter accidents, however, were responsible for 15 fatal injuries.
The remainder of the Part 135 accidents involved piston-powered aircraft, including 15 twins: six Piper Navajos, four twin Cessnas, two twin-Beech 18s, two Beech Barons and a Grumman G44. The 25 other Part 135 accidents involved single-engine piston aircraft.
Note: The predominance of any particular airplane or helicopter should not be interpreted to mean that those aircraft are unsafe, merely that those machines are used more often in charter than others.