- Date
- July 11, 1996, 17:30 local (22:30 UTC)
- Place
- Cottondale, FL
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N102HTHiller UH-12E
- Weather
- Visual (VMC) · Day
- Status
- Completed · report April 29, 1997
- Report
- Approved by Office Director
- FAA report
- 19960711044029A
- Case key
- 3739
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
failure of the main rotor drive torsional coupling and inner gimbal ring, which resulted in jamming of the flight controls during an attempted 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
Approximately two minutes into the climbout, the pilots felt a vibration in the airframe followed by a loud bang. The pilots entered an autorotation and selected a field for a forced landing. The pilots reported that, subsequently, as they were attempting to control the helicopter, the flight controls would not respond to inputs. Control of the helicopter was lost, and it impacted the ground inverted. Examination of the helicopter disclosed that the main drive clutch and engine gimble ring with the torsional coupling had failed. Debris from the failed components was not recovered for examination. A review of the maintenance logs showed that the drive coupling assembly had 511 hours of total service since new. Wreckage examination also disclosed that the entire transmission assembly had rotated from its normally installed position, and that the flight control rods were displaced from their normal position.
Factual narrative
On July 11, 1996, at 1730 central daylight time, a Hiller UH-12E, N102HT collided with the ground and was substantially damaged during a forced landing near Cottondale, Florida. Neither of the two commercial pilots were injured. The helicopter was being operated under the provisions of Title 14 CFR Part 91 by the pilot. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed for the local flight. The flight departed Jackson Heliport at 1715 Central Daylight Time.
Approximately two minutes into the climbout, the pilots felt a vibration in the airframe followed by a loud bang. The pilots initially stated that the helicopter had lost tail rotor control, at which time they selected a field for a forced landing. As the pilots attempted to control the helicopter, they reported that the flight controls would not respond to the inputs. Total control of the helicopter was lost; the helicopter impacted the ground inverted.
Examination of the helicopter disclosed that the main drive clutch and engine gimble ring with the torsional coupling had failed. Debris from the failed components was not recovered for examination. A review of the maintenance logs showed that the drive coupling assembly had 511 hours of total time in service since new. The wreckage examination also disclosed that the entire transmission assembly had rotated from its normally installed position, and that the flight control rods were displaced from their normal positions.
Aircraft
- Registration
- N102HT
- Reported as
- Hiller UH-12E
- Category
- Helicopter
- Serial number
- 5218
- Airframe hours
- 515
- Engine
- Lycoming VO-540-C2A, 305 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Part 91
- Operator
- James E Willoughby
- Registered owner
- Helicopter Technology, Inc.
- Airworthiness certificate
- Special, Restricted (Special)
- Last inspection
- Annual · July 5, 1996 · 3 hours before
- Departed
- Jackson Helprt, FL
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
- 45
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Center
- Flight hours
- 5,567 total · 77 in this make and model · 5,493 as pilot in command · 166 in the last 90 days · 2 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 60° at 10 knots
- Visibility
- 6 statute miles
- Lowest ceiling
- None
- Temperature
- 90 °F, dew point 72 °F
- Altimeter
- 29.00 inHg
- Observed at
- DHN, 40 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.