SEA00LA170 · Hughes 369E
Hughes 369E · Accident: loss of engine power during initial climb
From Cavanaugh Bay Airport (66S) to Priest Lake Usfs Airport (67S)
Event
- NTSB case
- SEA00LA170
- 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
- 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 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
- N570CA
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Cavanaugh Bay Airport (66S)To Priest Lake Usfs Airport (67S), NORDMAN, ID
- 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
- Loss of engine power
- 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
- Engine instruments, egt/tot gage › Out of calibration
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
Shortly after takeoff, the engine lost power. The pilot initiated an emergency running landing, which resulted in the main rotor blades contacting and subsequently severing the tail boom during the landing phase. The engine and associated components were inspected. The turbine outlet temperature (TOT) indicating system was inspected to verify calibration, which is to be calibrated inspected during all 300-hour inspections. The test revealed that the TOT indicated on the cockpit gage was below actual engine outlet temperatures, and that lower than actual TOT readings provided to the pilot via the cockpit TOT gage may have resulted in numerous operations being conducted in higher temperature ranges than that authorized by the Pilot's Flight Manual and/or the engine manufacturers temperature limitations. The engine teardown inspection confirmed that the failures and stress ruptures found throughout the engine turbine assembly components were a result of high temperature engine operation above 2000F.
Probable cause
The turbine outlet temperature indicating system was out of calibration. Factors included improper maintenance calibration, which resulted in the over temperature of the turbine assembly.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA00LA170
- Event ID
- 20001212X21874
- Case number
- SEA00LA170
- 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: 1a866954e18bddf4c16fa40c4ea7f8ce5268cb18e3225ecc9042fc88fe096785; retrieved 2026-09-18T16:27:36.886Z.