- Date
- January 30, 1990, 13:10 local (19:10 UTC)
- Place
- Janesville, WI
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N117MMBB BK-117A-1
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 30, 1992
- Report
- Approved by Office Director
- FAA report
- 19900130001369A
- Case key
- 14626
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 pilot-in-command failed to ensure that the engine cowling latches were properly secured prior to departing on the maintenance test flight; the cowling came loose during flight, and contacted the main rotor blades before it separated from the helicopter.
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 stated that he and a company mechanic were in cruise flight at 2,000 feet MSL on a maintenance flight test, when he heard a noise, 'observed debris in all directions from the main rotor...(and) severe vibration was experienced.' The pilot made an emergency landing in a snow-covered field. Post-accident examination revealed that the engine cowling on the left side of the aircraft had separated while in flight, contacting and damaging the main rotor blades. Several pieces of the seperated cowling were recovered and inspected. The latches showed no malformation/stretching, and appeared to be capable of normal operation.
Aircraft
- Registration
- N117M
- Reported as
- MBB BK-117A-1
- Category
- Helicopter
- Serial number
- S-7023
- Airframe hours
- 3,397
- Engine
- Lycoming LTS-101-650B1, 600 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Part 91
- Operator
- Omni Flight Helicopters, Inc.
- Registered owner
- First Security Bank Of Utah
- Airworthiness certificate
- Standard, Normal
- Last inspection
- AAIP · January 12, 1990 · 10 hours before
- Departed
- JVL · Janesville, WI
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
- 36
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Right
- Flight hours
- 5,869 total · 62 in this make and model · 5,799 as pilot in command · 78 in the last 90 days · 16 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 280° at 18 knots, gusting 25
- Visibility
- 15 statute miles
- Lowest ceiling
- None
- Temperature
- 41 °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.