ANC05LA107 · Aerospatiale AS-350BA
Aerospatiale AS-350BA · Accident: total loss of engine power (mechanical failure) during initial climb
From Juneau International Airport (PAJN) to an unrecorded destination
Event
- NTSB case
- ANC05LA107
- 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
- Charter & commuter
- 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 AS-350BA
- Aircraft type
- Aerospatiale AS-350
- 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
- N57958
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Juneau International Airport (PAJN), Juneau, AKTo 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 135: Air Taxi & Commuter
- 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
- Initial climb
- 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
- Total loss of engine power (mechanical 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
- Miscellaneous, bolt/nut/fastener/clamp/spring › Disconnected
- Turboshaft engine, power output shaft › Separation
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 certificated pilot was departing on a local area sightseeing flight under Title 14, CFR Part 135, in a skid-equipped helicopter. During the initial climb, the engine lost power about 75 feet above the ground. The pilot entered an autorotation and attempted to cushion the landing, but the helicopter landed hard, collapsing the landing gear, and wrinkling the tail boom. A post-touchdown fire was burning in the engine compartment as the occupants exited the helicopter. Postaccident examination of the engine revealed that a retaining leaf spring, normally installed within engine Module 1 to hold several oil tubes in place, became unclipped. The legs of the spring made contact with the adjacent rotating engine power shaft. The shaft was severed, which resulted in an overspeed and failure of the free turbine. The engine had accrued 737.9 hours since Modules 2 and 3 were repaired in 2003, and Module 1 underwent a visual inspection. No maintenance had been done on Module 1 since the 2003 inspection.
Probable cause
A loss of engine power during takeoff initial climb due to the separation of the engine power turbine shaft, the failure of which was due to a disconnected adjacent leaf spring, which resulted in an emergency landing after takeoff and subsequent hard landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC05LA107
- Event ID
- 20050727X01110
- Case number
- ANC05LA107
- 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, 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: 2c2956256826af4c23d698bd71448aa58cdded283d976dca8aca8d1562e056a9; retrieved 2026-09-18T14:59:55.458Z.