- Date
- February 26, 2011, 10:00 local (18:00 UTC)
- Place
- Colusa, CA
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N236HAHiller UH-12E
- Defining event
- Maneuvering-low-alt flying: Settling with power/vortex ring state
- Weather
- Visual (VMC) · Day
- Status
- Completed · report June 20, 2011
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Administration
- FAA report
- 20110226002689A
- Case key
- 78441
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 an adequate airspeed and an inadvertent encounter with settling with power while flying downwind.
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 reported that he and the owner of the helicopter were flying a reconnaissance flight in preparation for a possible frost control flight the following morning. They were attempting to identify potential obstacles in the area. As they were flying slowly over the north edge of an almond orchard he initiated a descent, and slowed the helicopter to just above effective translational lift. He turned southbound and noted a 7- to 10-mile-per-hour tailwind. He reported that the tailwind, coupled with the descent, caused the helicopter to enter a settling with power condition. He stated that due to the close proximity of the trees he was not able to perform a normal recovery of lowering the collective and applying forward cyclic control. The helicopter descended between a row of trees and the main rotor blades struck the trees. The pilot stated that there were no mechanical malfunctions with the helicopter before the accident.
Factual narrative
The pilot reported that when the accident occurred he and the owner of the helicopter were flying a reconnaissance flight in preparation for a possible frost control flight the following morning. They were attempting to identify potential obstacles in the area. The departure was west of the accident site and near an almond orchard. As they were flying slowly over the north edge of the orchard the pilot initiated a descent, as well as slowing the helicopter to just above effective translational lift. He turned southbound and noted a 7- to 10-mile-per-hour (mph) tailwind. The pilot reported that the tailwind, coupled with the descent, caused the helicopter to enter a settling with power condition. He stated that due to the close proximity of the trees he was not able to perform a normal recovery of lowering of the collective and applying forward cyclic control. The helicopter descended between a row of trees and the main rotor blades struck the trees. The pilot stated that there were no mechanical malfunctions with the helicopter before the accident.
Aircraft
- Registration
- N236HA
- Reported as
- Hiller UH-12E
- Category
- Helicopter
- Serial number
- HA3063
- Airframe hours
- 7,224
- Engine
- Lycoming VO-540 SERIES, 310 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Airworthiness certificate
- Special, Restricted (Special); Standard, Normal
- Last inspection
- Annual · November 20, 2010 · 35 hours before
- Departed
- Colusa, CA
- Destination
- Colusa, CA
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
- 34
- Injuries
- None
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- April 8, 2010
- Seat
- Center
- Flight hours
- 852 total · 62 in this make and model · 772 as pilot in command · 6 in the last 90 days · 6 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 320° at 9 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 39 °F, dew point 30 °F
- Altimeter
- 29.92 inHg
- Observed at
- MYV, 25 nm away
Docket · 1
The files NTSB released with the investigation on March 21, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 286 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.
Other investigations on N236HA · 1
Matched to the same aircraft by N-number and date.