Garlick UH-1H accident near Darrington, Washington, December 14, 1998
On December 14, 1998 at about 7:00 pm local time, a Garlick UH-1H (helicopter), registered N94NW, was substantially damaged in an accident near Darrington, Washington. It was an other work-use flight under external-load helicopter rules (Part 133). 1 person was seriously injured. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The total separation of the vertical fin (stabilizer), as the result of fatigue cracks which initiated in the fourth rivet hole above where the fin extends from the tailboom.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 14, 1998 · about 7:00 pm local time
- Place
- Darrington, Washington · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Garlick UH-1H
- Registration
- N94NW · registry record · serial 66-1101
- Damage
- Substantial damage
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
While in a hover during heavy-lift aero-logging operations, the vertical fin separated from the tail boom, resulting in an uncontrolled descent into the terrain. During the investigation, the NTSB Materials Laboratory determined that the separation was due to the propagation of a number of fatigue cracks which had initiated within the fourth rivet hole above where the left side of the spar fin cap protruded from the tail boom. Although the FAA had previously issued Airworthiness Directive (AD) 97-20-09 to address the separation of vertical fins from UH-1 helicopters used in repeated heavy-lift operations, the Rotorcraft Directorate determined that the AD was not adequate. As a result, the Directorate initiated the formulation of a Priority Letter Airworthiness Directive requiring the replacement of the original fin spar with one that '...has been shown to account for the effects of repeated heavy-lift operations.'
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: rotorcraft: helicopter
- Flight time: 6,336 hours in all; 800 in this make and model; 210 in the last 90 days; 66 in the last 30 days; 6,336 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 7,240 hours
- Last inspection: continuous airworthiness programme, December 10, 1998; 10 hours since
- Maximum gross weight: 9,500 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming T53-L13B (turboshaft); 0 hours total
- Fire on the ground
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: not recorded
- Temperature: 39°F (4°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number SEA99LA020.