- Date
- November 27, 1991, 23:21 local (Nov 28, 1991, 07:21 UTC)
- Place
- Bridgeport, CA
- Injuries
- 4 fatal
- Damage
- Destroyed
- Phase of flight
- Enroute
- Aircraft
- N146RMAerospatiale SA 316B
- Weather
- Visual (VMC) · Night/dark
- Status
- Completed · report January 27, 1993
- Report
- Approved by Office Director
- FAA report
- 19911127053719A
- Case key
- 27392
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 helicopter's tail rotor drive shaft and drive shaft bearing due to undetermined reason(s).
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 aeromedical evacuation (ems-medevac) flt was made at ngt ovr mtn trrn. The plt interrupted his normal psn rprt & broadcast 'mayday' 3 times, giving his psn to a company dispatcher. He did not state the nature of the emergency. No further comm was recorded. Witnesses in a southbound auto saw the helicopter flying toward them from the south. They stated the helicopter's fuselage started rotating counter-clockwise. It then veered to the west, went out of sight, and crashed. All maj components, except about 33 inches of the tail rotor drive shaft & its #5 brg, were located. The tail boom was found in 3 sections. Rotational & longitudinal scoring damage was noted on the tail boom in the vcnty of the #3 & #5 brg supports. A lab rprt stated that the rotational dmg occurred before the gross deformation of the tail boom & subsequent in-flt breakup of the helicopter.
Aircraft
- Registration
- N146RM
- Reported as
- Aerospatiale SA 316B
- Category
- Helicopter
- Serial number
- 1614
- Airframe hours
- 7,525
- Engine
- Turbomeca ARTOUSTE IIIB, 858 horsepower, turbo shaft
- Damage
- Destroyed
- Flight
- Part 135
- Operator
- Rocky Mountain Helicopters
- Registered owner
- Rocky Mountain Helicopters
- Airworthiness certificate
- Standard, Normal
- Last inspection
- AAIP · October 25, 1991 · 53 hours before
- Departed
- Q18 · Bridgeport, CA
- Destination
- NONE · Reno, NV
- Flight plan
- Company VFR
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
- 44
- Certificate
- Airline transport
- Airplane ratings
- Single-engine land
- Instrument ratings
- Helicopter
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Right
- Toxicology
- Performed
- Flight hours
- 11,095 total · 2,163 in this make and model · 11,095 as pilot in command · 76 in the last 90 days · 28 in the last 30 days · 4 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Night/dark
- Visibility
- 3 statute miles
- Temperature
- 12 °F
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.