SEA07LA108 · Hughes 369D
Hughes 369D · Accident: total loss of engine power (mechanical failure) on approach
From Daniel K. Inouye International Airport (HNL) to Turtle Bay Resort Heliport (HI58)
Event
- NTSB case
- SEA07LA108
- 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
Hughes 369D
- 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
- N911FT
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Daniel K. Inouye International Airport (HNL), Honolulu, HITo Turtle Bay Resort Heliport (HI58), Kahuku, HI
- 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
- Approach · VFR pattern final
- 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
- Fluid, oil › Leak
- Lubricating system, oil line › Cracked
- Lubricating system, oil line › Fatigue
- Turboshaft engine, free(power) turbine › Seized
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
During an aerial surveillance flight, the helicopter's engine chip light illuminated, and the pilot headed towards a nearby heliport to make a precautionary landing. The pilot established a steep fast approach in case of engine failure while on approach. At approximately 100 feet above the ground and an airspeed of 65 knots, he applied power and began to slow the helicopter. At this point, the engine lost power, and the pilot entered an autorotation. The helicopter landed hard breaking both forward landing gear struts and spreading the rear struts. The main rotor blades impacted the tail boom, and the tail boom separated from the fuselage. Examination of the helicopter revealed heavy deposits of oil on the inner surfaces of the engine compartment as well as on the exterior surfaces of the engine. There was no oil in the airframe engine oil reservoir. The oil line leading from the engine gearbox to the oil pressure gauge was found cracked beneath the "B" nut securing it to the fitting on the engine gearbox. The N2 (power turbine) drive could not be rotated. Partial disassembly of the engine revealed damage to the number six, seven, and eight bearings consistent with a lack of adequate lubrication. Laboratory examination of the cracked oil line found fatigue cracking had propagated through an estimated 90 percent of the cross-sectional area of the tube. The cracking allowed lubricating oil to leak from the line resulting in oil starvation to the bearings leading to seizure of the power turbine.
Probable cause
Fatigue cracking of the oil line from the engine gearbox to the oil pressure gauge, which resulted in loss of engine lubricating oil, leading to seizure of the power turbine.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA07LA108
- Event ID
- 20070501X00491
- Case number
- SEA07LA108
- 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, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2007-04-20.
- API snapshot SHA-256: 35aaa01287c8d331ff1513e989d233424b0aa1c2d265cd993884d9de2c3b3414; retrieved 2026-09-18T14:45:22.128Z.