- Date
- April 30, 2019, 10:15 local (16:15 UTC)
- Place
- Sula, MT
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N350DLAerospatiale AS350
- Defining event
- Maneuvering-hover: Low altitude operation/event
- Weather
- Visual (VMC) · Day
- Status
- Completed · report March 20, 2020
- Report
- Approved by Office Director
- NTSB office
- General Aviation Accidents
- Parties
- FAA
- FAA report
- 20190430003639A
- Case key
- 99359
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 pilot's failure to maintain adequate clearance from ground equipment, which resulted in a tail rotor blade impact.
Findings · 2
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
The helicopter pilot reported that, after an agricultural application flight, he set the bucket down in a predetermined operations zone near a semi-truck loading hopper to be refilled. He added that another truck arrived to top off the semi-truck hopper, which emitted fertilizer dust and led to the pilot being concerned that it would deteriorate visibility. He advised the ground crew that he was going to temporarily move out of the operations zone. The pilot reported that he set the bucket in the new temporary operations zone. As the skid steer approached, he eased the helicopter backward to keep the other ground equipment in his view. The pilot heard a "bang," disconnected the helicopter from the long-line, and then landed the helicopter without further incident. Postaccident examination revealed that the auger from the semi-truck hopper was fully extended behind the helicopter and that a tail rotor blade had sustained substantial damage. The pilot reported that he might have backed the helicopter into the extended auger. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
Factual narrative
The helicopter pilot reported that, after an aerial application flight, he set the bucket down in a pre-determined operations zone near a semi-truck loading hopper to be refilled. He added that another truck arrived to top off the semi-truck hopper, which emitted fertilizer dust that caused the pilot concerns for his deteriorating visibility. He advised the ground crew that he was going to move out of the operations zone temporarily. The pilot reported that he set the bucket in the new temporary operations zone. As the skid steer approached, he eased the helicopter backward to keep the other ground equipment in his view. The pilot heard a "bang", disconnected from his long-line, and landed the helicopter without further incident. Postaccident examination revealed that the auger from the semi-truck hopper was fully extended behind the helicopter and tail rotor blade sustained substantial damage. The pilot suspected that he backed the helicopter into the extended auger. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
Aircraft
- Registration
- N350DL
- Reported as
- Aerospatiale AS350 (B3)
- Category
- Helicopter
- Serial number
- 4508
- Built
- 2008
- Airframe hours
- 1,103.2
- Engine
- Safran Arriel 2B1, 749 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Aerial application · Part 137
- Operator
- Mission Mountain Helicopters
- Registered owner
- Pj Helicopter Llc
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · April 24, 2019
- Departed
- Soula, MT
- Destination
- Soula, MT
- Equipment
- ADS-B, Electronic multifunction display
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
- Injuries
- None
- Certificates
- Commercial, Airline transport, Flight instructor
- Airplane ratings
- Multi-engine land, Single-engine land, Multi-engine sea, Single-engine sea
- Instrument ratings
- Airplane, Helicopter
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- March 15, 2019
- Seat
- Right
- Restraint
- 3-point
- Flight hours
- 8,773 total · 3,125 in this make and model · 8,700 as pilot in command · 26 in the last 90 days · 11 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 200° at 8 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- 10,000 ft overcast
- Temperature
- 36 °F
Docket · 2
The files NTSB released with the investigation on May 13, 2019, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.9 MB 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.