Hughes 369D accident near Woodruff, Utah, January 4, 1999
On January 4, 1999 at about 11:45 pm local time, a Hughes 369D (helicopter), registered N5013P, was substantially damaged in an accident near Woodruff, Utah. It was a public-use flight under general aviation rules (Part 91). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A partial loss of engine power due to erosion in the compressor assembly module. Factors were a missing rotating labyrinth seal, the installation of which had not been performed by unknown maintenance personnel.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 4, 1999 · about 11:45 pm local time
- Place
- Woodruff, Utah · map
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 369D · all 369Ds on the register
- Registration
- N5013P · no longer on the register · serial 610984D
- Damage
- Substantial damage
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
As the helicopter was being maneuvered at low altitude, the pilot heard a series of compressor stalls, accompanied by a rapid decay of rotor rpm. The helicopter struck the ground, spun around and rolled over on its right side. The engine was functionally tested and was 20 horsepower below overhaul specifications. The compressor stalled repeatedly. Compressor disassembly disclosed case liner erosion, most noticeably at the 5th and 6th stages, and the rotating labyrinth seal was missing. After replacing the seal and installing a slave compressor module, the engine tested normal.
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: single-engine land; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 10,300 hours in all; 300 in this make and model; 120 in the last 90 days; 70 in the last 30 days; 9,988 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 6,484 hours
- Last inspection: 100-hour inspection, November 16, 1998; 30 hours since
- Maximum gross weight: 3,000 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: EVW Evanston WY at 9:30 pm
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 250° at 15 knots
- Visibility: 50 statute miles
- Sky: scat at 20,000 ft
- Temperature: 36°F (2°C), dew point 46°F (8°C)
- Altimeter: 30.00 inHg
- Observation at 10:56 pm from EVW, 23 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.