Monday, August 27, 2018

Loss of Control in Flight: Robinson R22 Beta, N4085T; accident occurred August 24, 2018 at Corvallis Municipal Airport ( KCVO), Benton County, Oregon

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Portland, Oregon

Aviation Accident Final Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Aviation Accident Data Summary - National Transportation Safety Board:

Location: Corvallis, OR
Accident Number: GAA18CA508
Date & Time: 08/24/2018, 0930 PDT
Registration: N4085T
Aircraft: Robinson R22
Aircraft Damage: Substantial
Defining Event: Loss of control in flight
Injuries: 1 Minor
Flight Conducted Under: Part 91: General Aviation - Instructional


The solo student helicopter pilot reported that he was practicing takeoffs and landings to a taxiway and that he was preparing for a steep approach. The steep approach required more left pedal, which resulted in the helicopter being "out of trim (right yaw)." A tailwind accelerated the right yaw. He attempted to recover but added "insufficient left pedal." The helicopter then spun and landed hard. The helicopter came to rest on its left side.

The helicopter sustained substantial damage to the windshield, fuselage, and tailboom.

The student reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.

The automated weather observation station located on the airport reported that, about 34 minutes before the accident, the wind was from 290° at 3 knots. The same automated station reported that, about 26 minutes after the accident, the wind was from 030° at 6 knots. The helicopter was approaching a taxiway parallel to runway 17.

The Federal Aviation Administration's Helicopter Flying Handbook, FAA-H-8083-21A, contained a section titled "Weathercock Stability," which stated:

In this region, the helicopter attempts to weathervane, or weathercock, its nose into the relative wind. Unless a resisting pedal input is made, the helicopter starts a slow, uncommanded turn either to the right or left, depending upon the wind direction. If the pilot allows a right yaw rate to develop and the tail of the helicopter moves into this region, the yaw rate can accelerate rapidly. In order to avoid the onset of LTE [loss of tail rotor effectiveness] in this downwind condition, it is imperative to maintain positive control of the yaw rate and devote full attention to flying the helicopter. 

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The student helicopter pilot's inadequate torque pedal application during practice approaches with a tailwind, which resulted in a loss of yaw control and a subsequent hard landing.



Personnel issues
Aircraft control - Student pilot (Cause)

Environmental issues
Tailwind - Effect on operation

Factual Information

History of Flight

Other weather encounter
Loss of control in flight (Defining event)
Loss of tail rotor effectiveness
Hard landing
Collision with terr/obj (non-CFIT)

Student Pilot Information

Certificate: Student
Age: 35, Male
Airplane Rating(s): None
Seat Occupied: Right
Other Aircraft Rating(s): None
Restraint Used: 3-point
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 06/01/2018
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time:  (Estimated) 35.8 hours (Total, all aircraft), 35.8 hours (Total, this make and model), 7.2 hours (Pilot In Command, all aircraft), 22.3 hours (Last 90 days, all aircraft), 2.4 hours (Last 30 days, all aircraft), 1 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: Robinson
Registration: N4085T
Model/Series: R22 BETA
Aircraft Category: Helicopter
Year of Manufacture: 1991
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 1841
Landing Gear Type: Skid;
Seats: 2
Date/Type of Last Inspection: 08/02/2018, 100 Hour
Certified Max Gross Wt.: 1370 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 10161 Hours at time of accident
Engine Manufacturer: Lycoming
ELT: Not installed
Engine Model/Series: O-320-B2C
Registered Owner: Honey B Llc
Rated Power: 160 hp
Operator: Honey B Llc
Operating Certificate(s) Held: None
Operator Does Business As: Corvallis Aero Service
Operator Designator Code: 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KCVO, 250 ft msl
Distance from Accident Site: 0 Nautical Miles
Observation Time: 1656 UTC
Direction from Accident Site: 90°
Lowest Cloud Condition:
Visibility:  10 Miles
Lowest Ceiling: Broken / 4200 ft agl
Visibility (RVR):
Wind Speed/Gusts: 6 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: 30°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.14 inches Hg
Temperature/Dew Point: 18°C / 9°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Corvallis, OR (CVO)
Type of Flight Plan Filed: None
Destination: Corvallis, OR (CVO)
Type of Clearance: None
Departure Time: 0830 PDT
Type of Airspace: Class G

Airport Information

Runway Surface Type: Asphalt
Airport Elevation: 249 ft
Runway Surface Condition: Dry; Rough
Runway Used: N/A
IFR Approach: None
Runway Length/Width:
VFR Approach/Landing: Full Stop 

Wreckage and Impact Information

Crew Injuries: 1 Minor
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Minor
Latitude, Longitude:  44.500000, -123.283333 (est)

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