- Date
- August 21, 2011, 06:55 local (13:55 UTC)
- Place
- Los Banos, CA
- Injuries
- 1 minor
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N948DSBell 47G-4
- Defining event
- Maneuvering-hover: Controlled flight into terr/obj (CFIT)
- Weather
- Visual (VMC) · Day
- Status
- Completed · report October 17, 2011
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Administration FSDO
- FAA report
- 20110821017499A
- Case key
- 81568
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 clearance from the power poles while maneuvering during low-altitude operations.
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 pilot was performing an agricultural application flight in the helicopter over a cantaloupe field. During the final pass along the field border, he observed bee boxes adjacent to power poles, and he shut off the spray applicator. After passing the boxes, he turned the spray applicator back on; his next recollection was of lying upside down in the field. Examination of the helicopter at the accident site revealed that the main rotor blades struck a set of wooden power poles at the 20-foot-level. The helicopter sustained substantial damage to the main rotor blades and fuselage structure. The pilot reported that he had flown an application flight over the same field a week prior, and was aware of the location of the power poles. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.
Factual narrative
The pilot was performing an agricultural application flight in the helicopter over a cantaloupe field. During the final pass along the field border, he observed bee boxes adjacent to power poles, and he shut off the spray applicator. After passing the boxes, he turned the spray applicator back on; his next recollection was of lying upside down in the field. Examination of the helicopter at the accident site revealed that the main rotor blades struck a set of wooden power poles at the 20-foot-level. The helicopter sustained substantial damage to the main rotor blades and fuselage structure. The pilot reported that he had flown an application flight over the same field a week prior, and was aware of the location of the power poles. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.
Aircraft
- Registration
- N948DS
- Reported as
- Bell 47G-4
- Category
- Helicopter
- Serial number
- 3140
- Airframe hours
- 8,954
- Engine
- Allison 250-C20B, 420 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Aerial application · Part 137
- Operator
- Double Springs LLC
- Registered owner
- Schuh Roger J
- Airworthiness certificate
- Special, Restricted (Special)
- Last inspection
- Annual · June 1, 2011 · 81 hours before
- Departed
- KLSN · Los Banos, CA
- Destination
- KLSN · Los Banos, CA
- Airport
- KLSN · Los Banos
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
- 40
- Injuries
- Minor
- Certificates
- Commercial, Flight instructor
- Instrument ratings
- Helicopter
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- August 10, 2010
- Seat
- Left
- Flight hours
- 1,643 total · 143 in this make and model · 1,583 as pilot in command · 243 in the last 90 days · 133 in the last 30 days · 5 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 310° at 3 knots
- Visibility
- 9 statute miles
- Lowest ceiling
- None
- Temperature
- 57 °F, dew point 54 °F
- Altimeter
- 29.89 inHg
- Observed at
- KMCE, 21 nm away
Docket · 3
The files NTSB released with the investigation on September 15, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 784 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.