On March 23, 2003, a Bell 47D (registration N74120) was involved in an aviation accident near Princetown, NY. Investigators recorded the probable cause as: The student's failure to maintain control while executing a takeoff to a hover, and the flight instructor's delayed remedial action. A factor in the accident was the muddy ground. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a training flight, a student pilot practicing hover taxiing lost control of the helicopter, which rolled right and struck the main rotor blades against the ground. No mechanical problems were reported.
Accident Sequence
The instructor had the student conduct approximately 18 takeoff and landings, each executed to and from a hover. The student experienced difficulty maintaining rotor RPM during these maneuvers. The helicopter then departed and flew to a private heliport. There, the student completed an "approach to the ground," and the instructor asked him to practice hover taxiing before terminating the flight. As the student started to apply collective, the instructor looked inside to check rotor RPM. When he looked back outside, the helicopter was in a nose-high, right-side-low attitude. The instructor lowered the collective and applied full left cyclic, but the roll to the right continued. The main-rotor blades impacted the ground, and the helicopter came to rest.
Examination Findings
Examination of the wreckage revealed that the rear of the right skid was in an area of mud.
Instructor Statement
The instructor stated that during all the flights and the accident sequence, he did not experience any mechanical problems with the helicopter.