NTSB CAROL · Event
Event ERA17CA099
Aircraft involved
Probable cause & findings
The student pilot's failure to relinquish the flight controls to the flight instructor, which resulted in a collision with terrain.
Factual narrative
The student pilot, who held a commercial fixed-wing pilot certificate, was performing hovering flight during his first helicopter lesson when the helicopter "suddenly jerked backwards." The helicopter's tail rotor gearbox and a portion of the tail rotor departed the helicopter, and the flight instructor landed the helicopter upright with no injuries to the two occupants.According to the flight instructor, he monitored the cyclic, collective, and tail rotor controls while explaining hovering flight, and surrendered each control to the student pilot one at a time until the student pilot was fully controlling the helicopter. As the helicopter transitioned backwards, and began a "spin to the left," he requested and took control of the helicopter, but the student pilot did not surrender the controls, and the flight instructor could not overpower the student pilot's inputs before the tail rotor collided with terrain. The flight instructor further stated that there were no mechanical deficiencies with the helicopter that would have precluded normal operation. The student pilot, who held a commercial fixed-wing pilot certificate, was performing hovering flight during his first helicopter lesson when the helicopter "suddenly jerked backwards." The helicopter's tail rotor gearbox and a portion of the tail rotor departed the helicopter, and the flight instructor landed the helicopter upright with no injuries to the two occupants. According to the flight instructor, he monitored the cyclic, collective, and tail rotor controls while explaining hovering flight and surrendered each control to the student pilot one at a time until the student pilot was fully controlling the helicopter. As the helicopter transitioned backward and began a "spin to the left," he requested and took control of the helicopter, but the student pilot did not surrender the controls, and the flight instructor could not overpower the student pilot's inputs before the tail rotor collided with terrain. The flight instructor further stated that there were no mechanical deficiencies with the helicopter that would have precluded normal operation. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12
NTSB Findings
Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).
- C Personnel issues-Task performance-Use of equip/info-Aircraft control-Student/instructed pilot - C
- C Personnel issues-Action/decision-Action-Lack of action-Student/instructed pilot - C
- C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-(general)-Attain/maintain not possible - C
Verbatim from NTSB's published report. Source file
NTSB_2017_ERA17CA099.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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