Bell 214B-1 accident near Hobart Bay, Alaska, March 6, 1992
On March 6, 1992 at about 3:30 pm local time, a Bell 214B-1 (helicopter), registered N314RM, was substantially damaged in an accident near Hobart Bay, Alaska. It was a flight of an unrecorded kind under external-load helicopter rules (Part 133). 2 people were seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
FATIGUE FAILURE OF THE COMPRESSOR ASSEMBLY IMPELLER, AND INADEQUATE QUALITY CONTROL BY THE MANUFACTURER. A FACTOR WHICH CONTRIBUTED TO THE ACCIDENT WAS THE MOUNTAINOUS/HILLY TERRAIN.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 6, 1992 · about 3:30 pm local time
- Place
- Hobart Bay, Alaska
- Type
- Accident
- Injuries
- 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 214B-1 · all 214B-1s on the register
- Registration
- N314RM · no longer on the register · serial 28041
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
THE HELICOPTER WAS HOVERING APPROX 200 FT ABOVE THE LOG WHICH WAS BEING ATTACHED TO THE CARGO HOOK. THE PILOTS HEARD A LOUD BANG FOLLOWED BY A LOSS OF ENGINE POWER. THE HELICOPTER AUTOROTATED INTO STEEP UNEVEN TERRAIN, THE ONLY AREA AVAILABLE. EXAMINATION OF THE ENGINE REVEALED FATIGUE FAILURE OF THE CENTRIFUGAL IMPELLER ENCOMPASSING A 60 DEG ARC. THIS SECTION SEPARATED FROM THE ENGINE AND HELICOPTER. ANALYSIS OF THE IMPELLER SHOWED THAT THE COOLING HOLES, ASSOCIATED ONLY WITH THE T5508D ENGINE, DID NOT HAVE THE PRESCRIBED RADIUS, AND CRACKS WERE FOUND EMANATING FROM THE OTHER COOLING HOLES. THE ENGINE RECORDS SHOW THAT THE IMPELLER HAD 5592.0 CYCLES WHEN INSTALLED IN THIS ENGINE IN APRIL 1991. THE COMPONENT SERVICE LIFE LIMIT OF THE IMPELLER IS 16,600 CYCLES.
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: multi-engine land; single-engine land; instructor: helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 13,000 hours in all; 3,500 in this make and model; 208 in the last 90 days; 56 in the last 30 days; 12,000 as pilot in command; 500 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 8,116 hours
- Last inspection: approved inspection programme, March 4, 1992; 17 hours since
- Maximum gross weight: 16,000 lb
- Seats: 11
- Landing gear: fixed
- Engine: Lycoming T5508D (turboshaft); 0 hours total
- Operator: Rocky Mountain Aerologging INC
The flight
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 99 statute miles
- Sky: clear
- Temperature: 45°F (7°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.
Other NTSB records under N314RM 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.