- Date
- November 14, 1988, 12:17 local (17:17 UTC)
- Place
- Mohawk, TN
- Injuries
- 2 fatal
- Damage
- Destroyed
- Phase of flight
- Approach
- Aircraft
- N9575FHughes 269C
- Weather
- Visual (VMC) · Day
- Status
- Completed · report January 24, 1990
- Report
- Approved by Office Director
- Case key
- 7862
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
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 helicopter had landed at a private airstrip and the instructor deplaned. The dual student remained in the helicopter with the engine running. The CFI reboarded and the student made the takeoff. Later, on downwind in traffic pattern, a witness reported a loud noise from the engine. The main rotor was observed to slow noticeably and the helicopter entered a very steep descent, impacting the ground about 1,000 feet south of the runway. The engine rod bolts on the number four cylinder had fractured. Examination of the flight controls revealed no evidence of preimpact failure. One of the rod bolts was metallurgically examined and showed cracking through 25 percent of the bolt. The fatigue was attributed to insufficient preload on the bolt. The engine had 813 hrs since a major overhaul and 36 hrs since annual inspection.
Aircraft
- Registration
- N9575F
- Reported as
- Hughes 269C
- Category
- Helicopter
- Serial number
- 440295
- Airframe hours
- 6,170
- Engine
- Lycoming HI0-360-D1A, 190 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Instructional · Part 91
- Registered owner
- Bruce Hodges And Associates
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · April 21, 1988 · 36 hours before
- Departed
- PVT · Morristown, TN
- Airport
- PVT · Cooper Field, runway 27, 2,250 × 50 ft, grass/turf
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
- Certificates
- Flight instructor, Commercial
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Left
- Toxicology
- Performed
- Flight hours
- 756 total · 604 in this make and model · 694 as pilot in command · 107 in the last 90 days · 53 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 55 °F, dew point -0 °F
Other investigations on N9575F · 1
Matched to the same aircraft by N-number and date.