- Date
- September 14, 2009, 19:06 local (Sep 15, 2009, 02:06 UTC)
- Place
- Irvine, CA
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Landing
- Aircraft
- N796SHRobinson Helicopter R22
- Defining event
- Landing-flare/touchdown: Hard landing
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 29, 2009
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Administration
- FAA report
- 20090914018089A
- Case key
- 74738
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 flight instructor's failure to maintain an adequate airspeed and his delayed recovery action during the practice autorotation, which resulted in a hard landing.
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 flight instructor informed the private helicopter pilot under instruction (PUI) that the purpose of the practice autorotation was to demonstrate ways in which to reach a suitable landing zone in the event that an engine failure were to occur in an area with limited landing zones. The intention was to focus on the glide with a power recovery before the need to flare. The instructor entered the autorotation while the PUI observed. The instructor was demonstrating s-turns, beginning with a right 90-degree turn, followed by a left 180-degree turn, and ending with a right 90-degree turn to bring the helicopter back to the original heading. The rotor rpm remained in the green arc or above during the entire maneuver. During the last right 90-degree turn, the helicopter passed through what the instructor estimated to be 200 feet above ground level (agl), where he decided to discontinue the autorotation due to insufficient airspeed (40 KIAS), and a higher than expected rate of descent, which lead to a lower than anticipated height above ground. During the time it took for the instructor to decide to abort the autorotation, the helicopter had descended to approximately 20-30 feet agl. The instructor initiated a flare, and he focused on keeping the skids level, but the right skid hit a dirt ledge adjacent to the proposed landing spot that was approximately 6 feet higher than the surface of the intended landing zone. As the right skid impacted the ground, the helicopter pitched forward, and the nose impacted the ground. The pilot reported no mechanical failures or malfunctions at the time of the accident.
Factual narrative
The flight instructor informed the private helicopter pilot under instruction (PUI) that the purpose of the practice autorotation was to demonstrate ways in which to reach a suitable landing zone in the event that an engine failure were to occur in an area with limited landing zones. The intention was to focus on the glide with a power recovery before the need to flare. The instructor entered the autorotation while the PUI observed, but was not on the controls. The instructor was demonstrating s-turns, beginning with a right 90-degree turn, followed by a left 180-degree turn, and ending with a right 90-degree turn to bring the helicopter back to the original heading. The rpm remained in the green arc or above during the entire maneuver. During the last right 90-degree turn, the helicopter passed through what the instructor estimated to be 200 feet above ground level (agl), where he decided to discontinue the autorotation due to insufficient airspeed (40 KIAS), and a higher than expected rate of descent, which lead to a lower than anticipated height above ground. During the time it took for the instructor to decide to abort the autorotation, the helicopter had descended to approximately 20-30 feet agl. The instructor initiated a flare, and he focused on keeping the skids level, but the right skid hit a dirt ledge adjacent to the proposed landing spot that was approximately 6 feet higher than the surface of the intended landing zone. As the right skid impacted the ground, the helicopter pitched forward, and the nose impacted the ground. The pilot reported no mechanical failures or malfunctions at the time of the accident.
Aircraft
- Registration
- N796SH
- Reported as
- Robinson Helicopter R22
- Category
- Helicopter
- Serial number
- 3731
- Airframe hours
- 4,054
- Engine
- Lycoming O-360 SERIES, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Operator
- Nu Vista Aviation LLC
- Registered owner
- Nu Vista Aviation LLC
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · August 29, 2009 · 50 hours before
- Departed
- CNO · Chino, CA
- Destination
- CNO · Chino, 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 · 2
As NTSB recorded them. NTSB leaves out names.
- Role
- Flight instructor
- Age
- 34
- Injuries
- None
- Certificates
- Flight instructor, Commercial
- Instrument ratings
- Helicopter
- Medical
- Class 1, With waivers/limitations
- Last flight review
- April 7, 2009
- Seat
- Left
- Flight hours
- 460 total · 405 in this make and model · 395 as pilot in command · 36 in the last 90 days · 10 in the last 30 days · 1 in the last 24 hours
- Role
- Pilot
- Age
- 23
- Injuries
- None
- Certificate
- Private
- Medical
- Class 1, With waivers/limitations
- Last flight review
- July 25, 2009
- Seat
- Right
- Flight hours
- 94 total · 94 in this make and model · 45 as pilot in command · 61 in the last 90 days · 25 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 250° at 7 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 68 °F, dew point 57 °F
- Altimeter
- 29.95 inHg
- Observed at
- SNA, 8 nm away
Docket · 1
The files NTSB released with the investigation on October 23, 2009, on NTSB’s docket system: statements, records, photos and specialists’ reports. 405 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.