WPR16LA188 · Bell 206B III
Hi Line Helicopters Bell 206B III · Accident while standing
From Rockport, WA to Rockport, WA
Event
- NTSB case
- WPR16LA188
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Government
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Bell 206B III
- Aircraft type
- Bell 206
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N6181A
- Operator
- Hi Line Helicopters
- Onboard fatalities
- Unknown
- Route
- From Rockport, WATo Rockport, WA
- Aircraft age
- About 23 years (built 1993)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Public Aircraft
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Standing · engine(s) operating
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Miscellaneous/other
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The commercial pilot reported that, after landing the helicopter on a flat area in remote, mountainous terrain, she reduced the throttle to the idle position and the left front seat passenger exited the helicopter. The pilot reported that, while the passenger was securing the door, the helicopter started to oscillate laterally. The pilot adjusted the flight controls and increased the throttle, and the lateral oscillations stopped. The passenger stated that the helicopter "bounced and lurched" while he was securing the door but that the tail rotor did not come in contact with any objects or terrain. The pilot subsequently shut down the engine and conducted a postflight inspection, which revealed substantial damage to the transmission system. The pilot stated there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
Damage observed on the pylon mount assembly and main rotor mast was consistent with a mast bumping event, during which the static stops contact the mast due to excessive rotor blade flapping. During ground operations with the rotor turning, the main rotor may be affected by wind gusts and flap to its limits, resulting in a light static stop-to-mast contact. In such an event, mast bumping may manifest itself as a light shudder felt throughout the helicopter. The more extreme the flapping, the more severe the shudder. Mast bumping can also occur during ground operation if the cyclic is incorrectly positioned or is moved sufficiently to tilt the rotor disc to an extreme position.
Probable cause
The pilot's failure to maintain helicopter control while on the ground, which resulted in mast bumping.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR16LA188
- Event ID
- 20160928X52917
- Case number
- WPR16LA188
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 5813046c9383d62189f29906b9f2ad0ea4db20f064ae3ba8fd54dcfa71aea0eb; retrieved 2026-09-16T04:19:33.264Z.