Hiller UH-12E accident near Vernal, Utah, November 1, 1985
On November 1, 1985 at about 11:30 pm local time, a Hiller UH-12E (helicopter), registered N400AH, was substantially damaged in an accident near Vernal, Utah (Vernal airport). It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 1, 1985 · about 11:30 pm local time
- Place
- Vernal, Utah · Vernal · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH-12E · all UH-12Es on the register
- Registration
- N400AH · registry record · serial 1177
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
THE PLT STATED HE HAD JUST DEPARTED A SITE LOCATED ON TOP OF A MOUNTAIN, WHICH IS APPROXIMATELY 12,200 FT MSL. THE PILOT SAID 30 SECONDS LATER, THE HELICOPTER LOST PARTIAL POWER. REQUIRING HIM TO MAKE A FORCE LANDING. THE INSPECTION OF THE TURBOCHARGER REVEALED THE COMPRESSOR IMPELLER RETAINING NUT HAD BACKED OFF, ALLOWING THE COMPRESSOR IMPELLER TO CONTACT THE COMPRESSOR SHROUD AND LEADING TO THE SEIZURE OF THE IMPELLER. THIS RESULTED IN THE FAILURE OF THE TURBOCHARGER.
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, private
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 4,641 hours in all; 4,260 in this make and model; 30 in the last 90 days; 4,200 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 6,334 hours
- Last inspection: annual inspection, October 6, 1985; 14 hours since
- Maximum gross weight: 1,845 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming TIVO-540-A2A (piston); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 46 statute miles
- Sky: scat at 20,000 ft
- Temperature: 50°F (10°C), dew point 21°F (-6°C)
- Altimeter: 30.00 inHg
- Observation at 10:45 pm from VEL, 39 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 |
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.
Other NTSB records under N400AH the same tail number, which may have belonged to a different aircraft at the time
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.