LAX01LA009 · Aerospatiale AS350BA
Aerospatiale AS350BA · Accident: airframe, component or system failure during landing
From Gillespie Field (SEE) to an unrecorded destination
Event
- NTSB case
- LAX01LA009
- 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
- 0
- 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
- General aviation
- 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
Aerospatiale AS350BA
- Aircraft type
- Aerospatiale AS350
- 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
- N189ND
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Gillespie Field (SEE)To not recorded
- Aircraft age
- Not recorded
- 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
- Part 91: General Aviation
- 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
- Landing
- First occurrenceThe 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
- Airframe, component or system failure
- 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
- Other maintenance personnel › Maintenance, annual inspection, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While positioning the helicopter from the ground to a storage cart, the pilot lost directional, made a hard landing, and the tail boom struck the ground. Prior to the loss of directional control, the pilot saw something depart the tail section. He attributed the loss of directional control to a tail rotor failure. He initiated an autorotation over the landing cart. He maneuvered away from the cart in order to land on the ground and prevent a partial landing on the cart. The on-scene investigation revealed the aft drive shaft coupling was detached from the tail rotor drive shaft. Three bolts retain the coupling. One bolt was found attached to the coupling, another bolt was found on the ground, and the third bolt, and two of the retaining nuts, were not located. Neither bolt exhibited stripped threads or deformation. The last maintenance performed on the helicopter was by the previous owner. A track and balance of the tail rotor system was performed about 48 flight hours prior to the accident. According to the manufacturer's maintenance instructions, the balancing is accomplished by placement of washers under the nuts that are used to secure the bolts that attach to the aft drive shaft coupling. These are the same nuts that were not located at the accident site. Maintenance instructions also specify that the bolts in this area should be checked for proper torque and safety after an inspection.
Probable cause
Improper torquing procedure of the aft tail rotor drive shaft coupling by maintenance personnel after tracking the tail rotor.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX01LA009
- Event ID
- 20001212X22189
- Case number
- LAX01LA009
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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. 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: ffd97b261f02a9e38d6c456ba3913902dac196939adf28754cb8dc9b8545b6cc; retrieved 2026-09-22T12:24:17.896Z.