# NTSB GAA18CA508: Robinson R22, N4085T, Corvallis, OR, August 24, 2018 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: August 24, 2018, 09:30 local (16:30 UTC) - Place: Corvallis, OR - Coordinates: 44.5, -123.283332 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.5000&lon=-123.2833&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report March 18, 2019 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 98160 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA18CA508 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98160/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98160 - Page: https://openairdocs.org/ntsb/GAA18CA508 ## Probable cause 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. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: yaw control](https://openairdocs.org/ntsb-findings/01062024): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [Robinson Helicopter R22 BETA, 11 cases](https://openairdocs.org/ntsb-findings/01062024/cases.md?model=7640110), [All aircraft, 149 cases](https://openairdocs.org/ntsb-findings/01062024/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [Robinson Helicopter R22 BETA, 96 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7640110), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Robinson Helicopter R22 BETA, 5 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=7640110), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Robinson Helicopter R22 BETA, 6 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=7640110), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Robinson Helicopter R22 BETA, 67 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7640110), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242); cases with it: [Robinson Helicopter R22 BETA, 10 cases](https://openairdocs.org/ntsb-events/242/sequence.md?model=7640110), [All aircraft, 100 cases](https://openairdocs.org/ntsb-events/242/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Robinson Helicopter R22 BETA, 54 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=7640110), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Robinson Helicopter R22 BETA, 85 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640110), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis 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. ## Factual narrative 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 spun, and landed hard. The helicopter came to rest on the left side. The helicopter sustained substantial damage to the windshield, fuselage, and tailboom. The student pilot 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. Federal Aviation Administration's Helicopter Flying Handbook, FAA-H-8083-21A, contains 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 in this downwind condition, it is imperative to maintain positive control of the yaw rate and devote full attention to flying the helicopter. ## Aircraft - Registration: [N4085T](https://openairdocs.org/deregistered/N4085T-2020-10-31), registration cancelled 2020-10-31, S/N 1841, built 1991 (OpenAirDocs) - Reported make and model: Robinson R22 (BETA) - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1841 - Year built: 1991 - Airframe hours: 10161 - Engines: Lycoming O-320-B2C 160 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Honey B Llc, doing business as Corvallis Aero Service - Registered owner: Honey B Llc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 2, 2018 - Departed: CVO, Corvallis, OR - Destination: CVO, Corvallis, OR - Airport: CVO, Corvallis Muni - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Student pilot; age 35; injuries: minor; student; medical: class 2, without waivers/limitations; seat: right; restraint: 3-point; flight hours: 35.7 total, 35.7 in this make and model, 7.1 as pilot in command, 22.2 in the last 90 days, 2.4 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 4,200 ft broken - Temperature: 64 °F, dew point 48 °F - Altimeter: 30.13 inHg - Observed at: KCVO ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20180824012219A](https://openairdocs.org/incident/20180824012219A), Aug 24, 2018: Robinson Helicopter R22 BETA, Corvallis, OR, Substantial damage. Student pilot with appropriate endorsements and solo flights completed was flying alone to build time and practice skills to prepare for private pilot… ## Docket (1 files) The files NTSB released with the investigation on November 19, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98160. 977 KB in all. - Accident Photo (item 1, .PDF, 1 photo, 977 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468449&FileExtension=.PDF&FileName=Accident%20Photo-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.