- Date
- February 20, 1991, 10:00 local (16:00 UTC)
- Place
- North Mankato, MN
- Injuries
- 2 serious, 1 minor
- Damage
- Destroyed
- Phase of flight
- Maneuvering
- Aircraft
- N8955FHughes 269C
- Weather
- Visual (VMC) · Day
- Status
- Completed · report October 8, 1992
- Report
- Approved by Office Director
- FAA report
- 19910220002889A
- Case key
- 15012
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 fatique failure of the tail boom support strut attachment cluster and the improper inspection of the cluster attachment.
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 reported that during the aerial observation flight he heard a loud noise from the back of the helicopter. The helicopter then began rotating clockwise and descended to impact with the terrain in a wooded area. Post accident imspection revealed a fatigue failure of the tail boom support strut cluster fitting (left side). An airworthiness directive issued in 1976 called for a daily visual inspection and a 200 hour dye penetrant inspection of the fitting. A logbook entry date August 15, 1990, stated all ad's had been complied with.
Aircraft
- Registration
- N8955F
- Reported as
- Hughes 269C
- Category
- Helicopter
- Serial number
- 1120172
- Engine
- Lycoming HIO-360-D1A, 190 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Business · Part 91
- Operator
- Helicopter Flight, Inc.
- Departed
- MKT · Mankato, MN
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
- 41
- Certificate
- Commercial
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Flight hours
- 2,244 total · 38 in this make and model · 2,207 as pilot in command · 58 in the last 90 days · 34 in the last 30 days · 8 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 210° at 6 knots
- Visibility
- 15 statute miles
- Lowest ceiling
- 10,000 ft overcast
- Temperature
- -0 °F, dew point -0 °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 N8955F · 1
Matched to the same aircraft by N-number and date.