- Date
- August 4, 1989, 11:00 local (16:00 UTC)
- Place
- Sebeka, MN
- Injuries
- 3 uninjured
- Damage
- Substantial damage
- Phase of flight
- Approach
- Aircraft
- N96117Bell 206-B2
- Weather
- Visual (VMC) · Day
- Status
- Completed · report September 30, 1991
- Report
- Approved by Office Director
- FAA report
- 19890804037079A
- Case key
- 34845
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
Power plant failure due to a fracture of the first stage turbine wheel, resulting in an uncontrolled autorotation.
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 was on an approach to a field site when he heard a loud 'bang' followed by an engine out light and audio warning. The pilot executed a forced landing, with loss of tail rotor control, which resulted in a hard landing. Teardown and examination of the engine revealed that the first stage turbine wheel fractured due to thermal fatigue cracking.
Aircraft
- Registration
- N96117
- Reported as
- Bell 206-B2
- Category
- Helicopter
- Serial number
- 975
- Airframe hours
- 4,460
- Engine
- Allison 250-C20, 400 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Aerial observation · Part 91
- Operator
- Imperial International Inc.
- Registered owner
- Mortenson, Sheldon A.
- Airworthiness certificate
- Standard, Normal
- Departed
- 18MN · Motley, MN
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 40
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Right
- Flight hours
- 3,417 total · 1,565 in this make and model · 3,251 as pilot in command · 181 in the last 90 days · 136 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 270° at 8 knots
- Visibility
- 12 statute miles
- Lowest ceiling
- 6,000 ft broken
- Temperature
- 82 °F, dew point 64 °F
- Altimeter
- 29.00 inHg
- Observed at
- PKD, 23 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.