SEA97LA198 · Garlick UH-1B
Garlick UH-1B · Accident en route
From Prairie City, OR to Prineville, OR
Event
- NTSB case
- SEA97LA198
- 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-1B
- 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
- N22753
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Prairie City, ORTo Prineville, OR
- 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
- Miscellaneous/other
- 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, installation, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While cruising at 2,000 feet above ground level and 100 knots, the helicopter's right transmission door separated from the aircraft, striking the tail rotor and 90-degree gearbox and knocking them off the aircraft. The pilot entered an autorotative descent to a forced landing in a field, but was unable to raise the collective for touchdown without inducing undesirable yaw. The aircraft landed hard in the forced landing. An FAA inspector found that the two rear cowl latch blocks (which attach the aft end of the separated door to the engine firewall) were missing and did not appear to have been installed, and that the cowl top latch was also unlocked. This enabled the door to lift enough to slide aft out of the front latches and separate from the aircraft. The FAA inspector subsequently found that the company mechanic who removed the latch blocks had not entered the work in the helicopter maintenance records, and that another company mechanic who reinstalled the cowls did not notice the blocks were missing and also improperly locked the top latch.
Probable cause
Improper installation of the transmission door by a company mechanic, resulting in inflight separation of the door (which then struck the tail rotor system) and consequent total loss of the tail rotor. Contributing to the accident were: inadequate recordkeeping by a company mechanic, and attainment of proper descent rate for the forced landing touchdown was not possible.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA97LA198
- Event ID
- 20001208X08755
- Case number
- SEA97LA198
- 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: 3e00b7dcee8023ab4081af86ab39daa70767600ddb4a8ab600a9f4818dde8912; retrieved 2026-09-21T11:51:29.576Z.