Probable cause
Failure of maintenance personnel to ensure that the tail rotor pitch change link bolt was properly secured, which resulted in an in-flight separation of the bolt and subsequent vibration.
NTSB analysis
The pilot reported that he had just entered a slow orbit when the helicopter experienced what he described as a severe vibration. The vibration was continuous and so severe that the pilot diverted to a nearby airport and landed. Postincident examination of the helicopter revealed that one of the tail rotor pitch change link bolts (to the pitch arm) was missing. The incident flight followed a 100-hour maintenance inspection that concluded earlier that day. The inspection included maintenance and service to the tail rotor assembly. The pilot reported that the pitch change link bolt (to pitch arm) was not correctly tightened and secured while in maintenance and subsequently loosened and released during the flight.
Text from the NTSB. Open the NTSB docket for WPR12IA248 for the full record.
Event
- Date
- May 22, 2012
- Type
- Incident
- Place
- Seattle, Washington
- Nearest airport
- Boeing Field (BFI)
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Eurocopter AS 350 B2
- N-number
- N105TV
- Category
- Helicopter
- Damage
- Minor
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Other work use
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.