SEA98FA077 · Garlick UH-1H
Garlick UH-1H · Accident: partial loss of engine power (mechanical failure) while maneuvering
From ID to an unrecorded destination
Event
- NTSB case
- SEA98FA077
- 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
Garlick UH-1H
- Aircraft type
- Garlick UH-1
- 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
- N98NW
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From IDTo 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
- Maneuvering
- 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
- Engine assembly, bearing › Failure
- Other maintenance personnel › Maintenance, alignment, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot reported that he had dropped off a load of chokers and was maneuvering to hook up to a load of logs when the engine began to make 'a weird squealing noise, followed by a constant series of compressor stalls, occurring about twice per second.' The airplane then lost all engine power, and the pilot performed a forced landing in a clearing. Post Crash Examination revealed that the No. 1 bearing (P/N:1-300-015-04; S/N:127AC) was heavily damaged. From observations of damage on the bearing raceways and the inner ring split faces, evidence indicated that both thrust and non-thrust sides of the inner ring had been misaligned, based upon ball path indications. Military records for the engine included an Unserviceable Tag. No evidence was found of specifics related to that failure code, nor was evidence found recording related corrective maintenance action
Probable cause
Failure of a misaligned main bearing in the engine. Factors include returning a previously unairworthy-tagged engine to service by the operator's maintenance personnel without sufficient information to identify and correct an unknown engine deficiency.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA98FA077
- Event ID
- 20001211X10185
- Case number
- SEA98FA077
- 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: 043af9eebd25a5f3da3965ba0754e42cc77243286b4cd49d0768286ddcee5052; retrieved 2026-09-22T17:46:17.916Z.