- Date
- September 9, 1990, 14:00 local (22:00 UTC)
- Place
- Kokhanok, AK
- Injuries
- 1 serious
- Damage
- Substantial damage
- Phase of flight
- Other
- Aircraft
- N385EHBell 206B
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 8, 1992
- Report
- Approved by Office Director
- NTSB office
- Alaska Regional Office
- FAA report
- 19900909038379A
- Case key
- 5449
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 failure of the compressor end of the air compressor scroll to tee tube assembly causing the engine to spool down. The forced landing in eneven, unprepared, and lightly forested terrain were factors.
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.
Analysis
The pilot experienced a spool down on the turbine engine. Examination of the engine revealed that the air compressor scroll to tee tube assembly compressor end fitting had broken. Metallurgical examination of the part showed that there were no material irregularities, that the tube bend development and linear measurements varied from the engineering drawings, and that the tube assembly failed in a fatigue mode. The origin was on the tube o.d. approximately 0.020 inch below the 'b' end flare radius.
Aircraft
- Registration
- N385EH
- Reported as
- Bell 206B
- Category
- Helicopter
- Serial number
- 1674
- Airframe hours
- 6,837
- Engine
- Allison 250-C20B, 420 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Other work use · Part 133
- Operator
- Era Aviation Inc., doing business as Era Helicopters
- Registered owner
- Era Aviation Inc.
- Airworthiness certificate
- Standard, Utility
- Last inspection
- AAIP · August 27, 1990 · 865 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
- 44
- Certificate
- Commercial
- Instrument ratings
- Helicopter
- Medical
- Class 1, Valid Medical--w/ waivers/lim
- Seat
- Right
- Flight hours
- 3,570 total · 1,775 in this make and model · 3,100 as pilot in command · 144 in the last 90 days · 85 in the last 30 days · 6 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 270° at 15 knots, gusting 20
- Visibility
- 15 statute miles
- Lowest ceiling
- 3,000 ft broken
- Temperature
- 50 °F
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 N385EH · 1
Matched to the same aircraft by N-number and date.