- Date
- July 16, 2007, 08:30 local (14:30 UTC)
- Place
- Sheep Mountain, MT
- Injuries
- 1 minor
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N164JSBell 206B II
- Weather
- Visual (VMC) · Day
- Status
- Completed · report November 29, 2007
- Report
- Approved by Office Director
- Parties
- Helena Flight Standards District Office
- FAA report
- 20070716015039A
- Case key
- 66228
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 external load net, attached directly to the cargo hook without the use of a long line, oscillated and made contact with the tail rotor system while maneuvering.
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 was transporting supplies with a cargo net from one mountain site to another. The sling loads consisted of steel angle iron, which was bagged and secured with velcro, and then placed into the cargo net. After delivering the fourth load, the pilot lifted off with only an empty bag inside the net. The Bell 206B rotorcraft flight manual, in the supplement for external loading, states, "Control movements should be made smoothly and kept to a minimum to prevent oscillation of sling load." According to a witness, as the helicopter departed, the net "floated very close to the propeller [tail rotor], then floated back down." The net, which was attached directly to the helicopter cargo hook without the use of a long line, swung back up again and impacted the tail rotor, cutting the cargo net and releasing the bag. The pilot heard noise and "thumping" sounds, accompanied by vibrations and yawing, and realized that he had a tail rotor strike. The pilot entered an autorotation at "25 miles per hour and 200 feet" above a timbered slope. The pilot selected a small, sloped, clearing as a landing zone, and upon touchdown, the helicopter rolled over, coming to rest on it's right side.
Factual narrative
The helicopter was transporting supplies with a cargo net from one mountain site to another. The sling loads consisted of steel angle iron, which was bagged and secured with velcro, and then placed into the cargo net. After delivering the fourth load, the pilot lifted off with only an empty bag inside the net. The Bell 206B rotorcraft flight manual, in the supplement for external loading, states, "Control movements should be made smoothly and kept to a minimum to prevent oscillation of sling load." According to a witness, as the helicopter departed, the net "floated very close to the propeller [tail rotor], then floated back down." The net, which was attached directly to the helicopter cargo hook without the use of a long line, swung back up again and impacted the tail rotor, cutting the cargo net and releasing the bag. The pilot heard noise and "thumping" sounds, accompanied by vibrations and yawing, and realized that he had a tail rotor strike. The pilot entered an autorotation at "25 miles per hour and 200 feet" above a timbered slope. The pilot selected a small, sloped, clearing as a landing zone, and upon touchdown, the helicopter rolled over, coming to rest on it's right side.
Aircraft
- Registration
- N164JS
- Reported as
- Bell 206B II
- Category
- Helicopter
- Serial number
- 955
- Airframe hours
- 5,043
- Engine
- Allison 250C20, 385 horsepower, turbo shaft
- Damage
- Substantial damage
- Fire
- On-Ground
- Flight
- External load · Part 133
- Operator
- Ronald L. Young, doing business as Eagle Aero, Inc.
- Registered owner
- J.R. Simplot Company
- Airworthiness certificate
- Standard, Normal
- Last inspection
- June 1, 2007
- Departed
- Mtn Drop Site, MT
- Destination
- Mtn Drop Site, MT
- Airport
- NONE · Off Airport
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
- 74
- Injuries
- Minor
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Multi-engine sea, Single-engine land
- Instrument ratings
- Helicopter
- Medical
- Class 2, With waivers/limitations
- Last flight review
- May 1, 2007
- Seat
- Right
- Flight hours
- 12,860 total · 3,000 in this make and model · 12,000 as pilot in command · 31 in the last 90 days · 8 in the last 30 days · 6 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 30 statute miles
- Lowest ceiling
- None
- Temperature
- 64 °F
- Altimeter
- 29.92 inHg
Docket · 2
The files NTSB released with the investigation on October 22, 2007, on NTSB’s docket system: statements, records, photos and specialists’ reports. 546 KB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.