WPR09CA448

NTSB accident investigation · Robinson Helicopter R22 · Irvine, CA · September 15, 2009

Accident · No injuriesData collectionFinal report
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.

Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedRobinson Helicopter R22: 1 caseAll aircraft: 1,681 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · Instructor/check pilotRobinson Helicopter R22: 18 casesAll aircraft: 9,295 casesProbable cause
Action: delayed actionPersonnel issues › Action/decision · Instructor/check pilotRobinson Helicopter R22: 7 casesAll aircraft: 894 casesProbable cause

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.