- Date
- March 26, 2021, 15:15 local (20:15 UTC)
- Place
- Dustin, OK
- Injuries
- 2 serious, 2 minor
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N178DFRobinson Helicopter R44 II
- Defining event
- Maneuvering-low-alt flying: Loss of control in flight
- Weather
- Visual (VMC) · Day
- Status
- Completed
- Report
- Approved by Office Director
- Investigation class
- Class 3
- NTSB office
- Central Region
- Parties
- Federal Aviation Administration; Will Rogers Flight Standards District Office
- FAA report
- 20210326005769A
- Case key
- 102855
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 insufficient monitoring of the helicopter’s power while flying at low altitude and at low airspeed, which resulted in the loss of rotor rpm and impact with a tree and terrain.
Findings · 3
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 pilot of the helicopter stated that, while maneuvering “low and slow” with three passengers onboard, he noticed “insufficient power” and shortly thereafter, the low rotor rpm warning annunciated. He applied full throttle and attempted to regain rotor rpm but was unsuccessful. The pilot stated that he was forced to land immediately, during which the helicopter impacted a tree then terrain, resulting in substantial damage. The pilot reported that there were no mechanical malfunctions or failures of the helicopter and recommended operating “at a lower gross weight.” Postacccident examination of the helicopter revealed no anomalies that would have precluded normal operation.
Factual narrative
On March 26, 2021, about 1515 central daylight time, a Robinson Helicopter Company R44 II, N178DF, was substantially damaged when it was involved in an accident near Dustin, Oklahoma. The private pilot and one passenger received serious injuries, and two passengers received minor injuries. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 aerial observation flight. The pilot stated that while maneuvering “low and slow” with three passengers onboard, he noticed “insufficient power” and shortly thereafter, the low rotor rpm warning annunciated. He applied full throttle and attempted to regain rotor rpm but was unsuccessful. The pilot stated that he was forced to land the helicopter immediately, during which the helicopter impacted a tree then terrain, resulting in substantial damage that included damage to the main rotor, fuselage, and tailboom. The pilot reported that there were no mechanical malfunctions or failures with the helicopter, and recommended operating “at a lower gross weight.” Postacccident examination of the helicopter revealed no anomalies that would have precluded normal operation.
Aircraft
- Registration
- N178DF
- Reported as
- Robinson Helicopter R44 II
- Category
- Helicopter
- Serial number
- 11969
- Built
- 2007
- Airframe hours
- 2,347
- Engine
- Lycoming IO-540-AE1A5, 290 hp, reciprocating
- Damage
- Substantial damage
- Flight
- Aerial observation · Part 91
- Operator
- Brush Popper Aviation LLC
- Registered owner
- Brush Popper Aviation LLC
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · January 18, 2021
- Departed
- F10 · Henryetta, OK
- Equipment
- Electronic flight bag or handheld device
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
- 59
- Injuries
- Serious
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Instrument ratings
- Helicopter
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- June 3, 2020
- Seat
- Right
- Restraint
- 4-point
- Flight hours
- 3,687 total · 1,447 in this make and model · 3,552 as pilot in command · 124 in the last 90 days · 82 in the last 30 days · 3 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 150° at 14 knots, gusting 21
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 75 °F, dew point 45 °F
- Altimeter
- 29.89 inHg
- Observed at
- OKM, 90 nm away
Docket · 5
The files NTSB released with the investigation on July 29, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 159 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.