Midflight, the main rotor strikes the fuselage. The main rotor and tail boom then separate from the airframe, and the rotorcraft falls from the sky. More than likely this occurrence — known as a “mast bump” — will end in fatality for all onboard. On March 9, 2013, a Robinson Helicopter Company R66 crashed in New Zealand’s Kaweka range after experiencing a mast. Mast rocking avoidance, detection and recovery; Loss of tail rotor effectiveness avoidance, detection and recovery ; Costs. R44: $825 per hour. 7 hours ground school: $500.00 * Training may be completed using the clients aircraft at a cost cost of $1000 per day.

Recent concerns have been raised regarding mast-bumping accidents in the R44 and R66 at high speeds when the aircraft is light. Although concerns are predominantly from the southern hemisphere, low-G mast bumping accidents are avoidable by following correct operating procedures and through good pilot judgement.