Probable cause
The failure of the vertical stabilizer control adapter due to reverse bending fatigue.
NTSB analysis
While in cruise flight, the helicopter experienced a hard right yaw and subsequent left nose tuck. The pilot was able to regain control of the helicopter and reduce the airspeed to under 100 knots. The flight continued to its destination without further incident. An examination revealed that the vertical stabilizer control system adapter failed. Metallurgical examination revealed that the failure mode was reverse bending fatigue. The vertical stabilizer control system adapter has since been redesigned. Installation of the improved design is now required by an Airworthiness Directive.
Text from the NTSB. Open the NTSB docket for CEN09IA003 for the full record.
Event
- Date
- Oct 8, 2008
- Type
- Incident
- Place
- Weatherford, Texas
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Md Helicopter Inc MD 900
- N-number
- N902RN
- Category
- Helicopter
- Damage
- Minor
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Positioning
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.