LAX90LA171 · Hughes 369E
Hughes 369E · Accident: total loss of engine power (mechanical failure) during initial climb
Event
- NTSB case
- LAX90LA171
- 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 369E
- 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
- N5217N
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo 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 133: Rotorcraft Ext. Load
- 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
- Company maintenance personnel › Maintenance, inspection, not performed
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE HELICOPTER LOST ENG POWER AND LANDED HARD. THE PLT REPORTED HE HAD JUST COMPLETED RELEASING AN EXTERNAL LOAD. THE HELICOPTER WAS ABOUT 125 FEET AGL IN A CLIMBING LEFT TURN WHEN THE PLT HEARD A LOUD BANG. THE PLT ENTERED AUTOROTATION. THE PLT NOTED THAT THE MAIN ROTOR RPM WAS LOW AND WAS UNABLE TO REGAIN ANY MAIN ROTOR RPM BEFORE THE LANDING FLAIR. AT TOUCHDOWN, THE MAIN ROTOR BLADES FLEXED DOWNWARD AND SEVERED THE TAILBOOM. THE THIRD STAGE COMPRESSOR HAD FAILED, DAMAGING THE REMAINING STAGES OF THE COMPRESSOR. THE COMPRESSOR CASE PLASTIC WAS ERODED. THE ENG HAD UNDERGONE MAJOR MAINTENANCE AT 1,774.5 HOURS WHICH REQUIRED THE REMOVAL OF THE TURBINE SECTION. THERE WAS NO EVIDENCE IN THE ENG LOGBOOKS OF THE COMPRESSOR SECTION BEING INSPECTED AT 1,750 HOURS AS REQUIRED BY THE MANUFACTURER. THE ENGINE MAINTENANCE MANUAL WARNS EROSION WILL CAUSE DAMAGE TO COMPRESSOR BLADES AND VANES.
Probable cause
FAILURE BY COMPANY MAINTENANCE TO PERFORM A MANDATORY COMPRESSOR SECTION INSPECTION THAT RESULTED IN THE UNDETECTED EROSION OF THE COMPRESSOR VANES AND ENGINE FAILURE. CONTRIBUTING TO THE ACCIDENT WAS THE FAILURE OF THE PILOT TO MAINTAIN ADEQUATE MAIN ROTOR RPM AT CRITICAL ALTITUDE.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX90LA171
- Event ID
- 20001212X23173
- Case number
- LAX90LA171
- 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 1990-05-11.
- API snapshot SHA-256: 306bfbcd612431e01cda217584e00ba6439580bb7880fbc2aeefc9411fdc1b6f; retrieved 2026-09-23T06:18:41.550Z.