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NTSB accident investigation · Robinson Helicopter R22 Beta II · Anchorage, AK · September 26, 2012

Accident · No injuriesData collectionFinal report
Date
September 25, 2012, 18:00 local (Sep 26, 2012, 02:00 UTC)
Place
Anchorage, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Emergency descent
Aircraft
N4171JRobinson Helicopter R22 Beta II
Defining event
Autorotation: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report December 19, 2012
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
Federal Aviation Administration
FAA report
20120925023289A
Case key
85148

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The flight instructor's inadequate supervision of the student pilot during a hovering autorotation, which resulted in a dynamic rollover.

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.

Attention/monitoring: monitoring other personPersonnel issues › Psychological · Instructor/check pilotRobinson Helicopter R22 BETA: 15 casesAll aircraft: 200 casesProbable cause
Action: delayed actionPersonnel issues › Action/decision · Instructor/check pilotRobinson Helicopter R22 BETA: 35 casesAll aircraft: 894 casesProbable cause
Performance/control parameters: directional controlAircraft › Aircraft oper/perf/capability · Not attained/maintainedRobinson Helicopter R22 BETA: 14 casesAll aircraft: 3,958 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 was providing primary helicopter flight instruction to a student pilot. The instructor reported that while practicing a series of hovering autorotations, he inadvertently allowed the student pilot to drift to the left during the descent. The instructor then took control of the helicopter, applied right cyclic, and raised the collective slightly to level the helicopter and arrest the descent, but the helicopter started to descend with the right skid low. The instructor then added left cyclic and raised the collective further in an attempt to cushion the landing. The helicopter then drifted to the right as the right skid subsequently struck the ground. After touchdown, the helicopter’s skids slid over the asphalt surface before the right skid “caught,” the helicopter rolled to the right, and the main rotor blades struck the ground. The helicopter came to rest on its right side, sustaining substantial damage to the fuselage, tail boom, and main rotor drive system. The instructor reported that there were no preaccident mechanical problems with the helicopter that would have precluded normal operation. He also stated that the accident might have been avoided if he had taken corrective action sooner and with less input on the cyclic.

Factual narrative

The certificated flight instructor (CFI) was providing primary helicopter flight instruction to a student pilot. The CFI reported that while practicing a series of hovering autorotations, he inadvertently allowed the student pilot to drift to the left during the descent. The CFI then took control of the helicopter, applied right cyclic and raised the collective slightly to level the helicopter and arrest the descent, but the helicopter started to descend with the right skid low. He then added left cyclic, and raised the collective further in an attempt to cushion the landing. The helicopter then drifted to the right as the right skid subsequently struck the ground. After touchdown, the helicopter’s skids slid over the asphalt surface before the right skid “caught” and the helicopter rolled to the right, and the main rotor blades struck the ground. The helicopter came to rest on its right side, sustaining substantial damage to the fuselage, tail boom and main rotor drive system. In his written statement to the NTSB, the pilot reported that there were no preaccident mechanical problems with the helicopter, and in the recommendations section of the NTSB 6120.1 form he reported that the accident might have been avoided if he had taken corrective action sooner, and with less input on the cyclic.

Aircraft

Registration
N4171J
Reported as
Robinson Helicopter R22 Beta II
Category
Helicopter
Serial number
4392
Airframe hours
2,096
Engine
Lycoming O-360-J2A, 124 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Alpine Air Alaska Inc
Registered owner
Alpine Air Alaska Inc
Airworthiness certificate
Standard, Normal
Last inspection
Annual · September 1, 2012
Departed
PAMR · Anchorage, AK
Destination
PAMR · Anchorage, AK
Airport
PAMR · Merrill Field, runway 05, asphalt

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
Flight instructor
Age
31
Injuries
None
Certificate
Flight instructor
Instrument ratings
Helicopter
Medical
Class 2, Without waivers/limitations
Last flight review
December 11, 2011
Seat
Right
Flight hours
338 total · 255 in this make and model · 271 as pilot in command · 127 in the last 90 days · 45 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
8,500 ft overcast
Temperature
48 °F, dew point 45 °F
Altimeter
29.30 inHg
Observed at
PAMR

Docket · 2

The files NTSB released with the investigation on October 29, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 973 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.