- Date
- March 6, 1992, 11:30 local (15:30 UTC)
- Place
- Hobart Bay, AK
- Injuries
- 2 serious
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N314RMBell 214B-1
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 9, 1993
- Report
- Approved by Office Director
- NTSB office
- Alaska Regional Office
- FAA report
- 19920306005209A
- Case key
- 5641
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The NTSB’s determination of the probable cause, and any contributing factors.
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.
Analysis
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.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Aircraft
- Registration
- N314RM
- Reported as
- Bell 214B-1
- Category
- Helicopter
- Serial number
- 28041
- Airframe hours
- 8,116
- Engine
- Lycoming T5508D, 2,950 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Part 133
- Operator
- Rocky Mountain Aerologging Inc
- Registered owner
- Rocky Mountain Helicopters Inc
- Airworthiness certificate
- Standard, Normal
- Last inspection
- AAIP · March 4, 1992 · 17 hours before
- Flight plan
- Company VFR
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 46
- Certificate
- Commercial
- Airplane ratings
- Multi-engine land, Single-engine land
- Instrument ratings
- Helicopter, Airplane
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Left
- Flight hours
- 13,000 total · 3,500 in this make and model · 12,000 as pilot in command · 208 in the last 90 days · 56 in the last 30 days · 8 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 99 statute miles
- Lowest ceiling
- None
- Temperature
- 45 °F
- Altimeter
- 29.00 inHg
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.
Other investigations on N314RM · 2
Matched to the same aircraft by N-number and date.