LAX90LA050 · Hughes 369HS
Air Kaui Hughes 369HS · Accident: partial loss of engine power (mechanical failure) en route
From Lihue Airport (LIH) to an unrecorded destination
Event
- NTSB case
- LAX90LA050
- 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
Hughes 369HS
- Aircraft type
- Hughes 369
- 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
- N9161F
- Operator
- Air Kaui
- Onboard fatalities
- Unknown
- Route
- From Lihue Airport (LIH), Lihue, HITo 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
- En route · cruise
- 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
- Partial 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
- Bleed air system, lines › Bent
- Bleed air system, lines › Fatigue
- Bleed air system, lines › Incorrect
- Company maintenance personnel › Maintenance, installation, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE CERTIFICATED AIR LINE TRANSPORT PILOT WAS CONDUCTING A HELICOPTER SIGHTSEEING FLIGHT WITH 4 PASSENGERS WHEN THE ENGINE SUDDENLY LOST POWER. THE PILOT MADE AN EMERGENCY AUTOROTATION TO THE BOTTOM OF A SMALL RIVER BOTTOM. WHILE LANDING, THE HELICOPTER ROLLED OVER. EXAMINATION OF THE ENGINE SHOWED THAT THE FUEL CONTROL PC TUBE TO THE POWER TURBINE GOVERNOR HAD FRACTURED, CAUSING THE ENGINE TO GO TO A FLIGHT IDLE CONDITION. THIS TUBE WAS FOUND TO EXCEED THE SPECIFIED REQUIRED LENGTH OF MANUFACTURE. DURING INSTALLATION, THE TUBE WAS BENT BY COMPANY MAINTENANCE PERSONNEL TO FIT. METALLURGICAL EXAM DISCLOSED A FRACTURE DUE TO FATIGUE NEAR THE FUEL CONTROL END. THIS FATIGUE WAS INTRODUCED BY BENDING STRESSES IN THE TUBE.
Probable cause
THE IMPROPER INSTALLATION OF THE PC TUBE BY COMPANY MAINTENANCE PERSONNEL, WHICH RESULTED IN FATIGUE FAILURE OF THE TUBE DUE TO INDUCED BENDING STRESSES.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX90LA050
- Event ID
- 20001213X29978
- Case number
- LAX90LA050
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1989-12-09.
- API snapshot SHA-256: 453ce72521f4b3b88a09410eb3833da2f527c39eb19da484054f20cb0d1fdc76; retrieved 2026-09-23T06:55:54.191Z.