- Date
- June 5, 1987, 20:15 local (Jun 6, 1987, 02:15 UTC)
- Place
- Choteau, MT
- Injuries
- 4 fatal
- Damage
- Destroyed
- Phase of flight
- Maneuvering
- Aircraft
- N4999NBell 206L-1
- Weather
- Visual (VMC) · Day
- Status
- Completed · report August 31, 1988
- Report
- Approved by Office Director
- FAA report
- 19870605019129A
- Case key
- 17111
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Analysis
The EMS helicopter was returning to great falls, MT, on 6/5/87 when it crashed. Its occupants had earlier participated in a rescue seminar at many glacier, MT. The wreckage was not found until 6/9/87. A video tape recovered from the wreckage disclosed the helicopter to be following a herd of big horn sheep up a 7000-FT mountain slope and flying slowly at tree-top level when it suddenly yawed to the right. Tests made on the audio portion of the video tape revealed main/tail rotor RPM was at 100% power until 3.5 sec before end of tape. At that time main/tail rotor RPM dropped to 94%. Evidence also disclosed helicopter to be flying at high gross weight, high density altitude, and with a tailwind.
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.
Aircraft
- Registration
- N4999N
- Reported as
- Bell 206L-1
- Category
- Helicopter
- Serial number
- 45497
- Airframe hours
- 1,297
- Engine
- Allison 250-C28B, 435 horsepower, turbo shaft
- Damage
- Destroyed
- Fire
- On-Ground
- Flight
- Part 135
- Operator
- Minuteman Aviation, doing business as [Ems]
- Registered owner
- R.S. Aviation Incorporated
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · June 1, 1987
- Departed
- Many Glacier, MT
- Destination
- Great Falls, MT
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
- 43
- Certificate
- Commercial
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Helicopter, Airplane
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Right
- Toxicology
- Performed
- Flight hours
- 4,548 total · 492 in this make and model · 4,236 as pilot in command · 84 in the last 90 days · 15 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 180° at 16 knots, gusting 24
- Visibility
- 40 statute miles
- Lowest ceiling
- 14,000 ft broken
- Temperature
- 73 °F, dew point 46 °F
- Altimeter
- 29.00 inHg
- Observed at
- GTF, 57 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.