# NTSB WPR20LA110: Piper PA22, N4837Z, Pinedale, WY, March 16, 2020 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: March 16, 2020, 17:20 local (23:20 UTC) - Place: Pinedale, WY - Coordinates: 42.796943, -109.810554 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.7969&lon=-109.8106&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Piper Aircraft, FAA-FSDO - NTSB case key (mKey): 101078 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20LA110 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101078/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101078 - Page: https://openairdocs.org/ntsb/WPR20LA110 ## Probable cause A loss of airplane control during approach for reasons that could not be determined based on available evidence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-22-108, 12 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7102204), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Piper PA-22-108, 5 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=7102204), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Piper PA-22-108, 4 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7102204), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) ## Analysis The student pilot reported that he was drifting to the right while on approach to land when the flight instructor took over controls. The flight instructor reported that he applied rudder control inputs; however, the rudder pedals didn’t move for about 6 to 7 seconds and the airplane did not align with the runway. The flight instructor reported that he thought that the glareshield mounted tachometer timing box could have been trapped behind the rudder pedals. The tachometer timing box was located at the accident site and had been thrown from the wreckage. A portion of the instrument panel mounted tachometer housing was found behind the rudder pedals. Further examination of the tachometer gauge revealed damage consisted with impact damage as a result of the accident and did not appear to have interfered with the movement of the rudder pedals. Examination revealed no anomalies with the airframe that would have precluded normal operation. Multiple examinations of the rudder system did not reveal any evidence of a rudder malfunction or jam. ## Factual narrative On March 16, 2020, about 1720 mountain daylight time, a Piper PA-22-108, N4837Z, was substantially damaged when it was involved in an accident near Pinedale, Wyoming. The student pilot had minor injuries and the flight instructor was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The student pilot reported that the flight instructor took control of the airplane on final approach to runway 29 because the airplane was drifting to the right. The flight instructor later reported that after he took control of the airplane, he applied rudder control inputs. He reported that during a 6-to-7-second time period, the rudder pedals would not move. The airplane did not align with the runway and soon after impacted terrain near the runway. Examination of the recovered airframe by an airframe and powerplant mechanic revealed substantial impact damage to both wings, fuselage and engine mount. The left wing, from the side strut to the tip was partially separated due to the impact with the ground during the accident sequence. The left aileron inboard attachment bracket separated from the left aileron bellcrank. Corrosion was noted between the aileron bracket and aileron bellcrank mounting surfaces. The remaining rivet material left in the aileron and bellcrank bracket exhibited overload necking signatures. The airplane's flight control cables were intact. The rudder control cable rear pulleys were unable to be rotated freely by hand. During the flight control cable continuity check, the cables moved past the pulleys with little resistance. Nothing was impeding the rudder pedals from their normal movement. In another follow-up examination, the pulleys were stiff when rotated by hand and the cables were undamaged. The flight instructor reported that he thought that the glareshield mounted tachometer timing box could have been trapped behind the rudder pedals. The tachometer timing box was located at the accident site and had been thrown from the wreckage. A portion of the instrument panel mounted tachometer housing was found behind the rudder pedals. Further examination of the tachometer gauge revealed damage consisted with impact damage as a result of the accident. An NTSB Form 6120.1 Pilot/Operator Aircraft Accident/Incident Report was not summited by the student pilot or the flight instructor. ## Aircraft - Registration: [N4837Z](https://openairdocs.org/deregistered/N4837Z-2020-07-31), registration cancelled 2020-07-31, S/N 22-8411, built 1961 (OpenAirDocs) - Reported make and model: Piper PA22 (108) - Registry model: [Piper PA-22-108](https://openairdocs.org/model/piper-pa-22-108) (registry code 7102204) (OpenAirDocs) - Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 22-8411 - Year built: 1961 - Engines: Lycoming O-235 SERIES reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Departed: PNA, Pinedale, WY - Destination: PNA, Pinedale, WY - Airport: PNA, Ralph Wenz Field, runway 29, 8,900 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 79; injuries: serious; airline transport; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: basicmed, with waivers/limitations; seat: right; restraint: lap only - Student pilot; age 18; injuries: minor; student; medical: unknown; seat: left; restraint: lap only ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 7,500 ft broken - Temperature: 28 °F, dew point 27 °F - Altimeter: 30.05 inHg - Observed at: KPNA ## 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 20200316000739A](https://openairdocs.org/incident/20200316000739A), Mar 16, 2020: Piper PA-22-108, Pinedale, WY, Substantial damage. Control of aircraft was lost on approach to landing. Pilots stated they felt like something broke and caused aircraft to yaw to the right. ## Docket (5 files) The files NTSB released with the investigation on March 15, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101078. 14.5 MB in all. - Record of conversation-flight instructor (item 1, PDF, 1 page, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9715439&FileExtension=pdf&FileName=Record%20of%20Conversation-Holden_Redacted-Rel.pdf - Record of conversation-student pilot (item 2, PDF, 1 page, 139 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13366891&FileExtension=pdf&FileName=Record%20of%20Conversation-Student%20Pilot_Redacted-Rel.pdf - Wreckage examination summary (item 3, PDF, 5 pages, 7 photos, 969 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9715906&FileExtension=pdf&FileName=WPR20LA110%20Wreckage%20Examination%20Summary-Rel.pdf - Maintenance logbook-last annual inspection (item 4, PDF, 1 page, 12.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9715948&FileExtension=pdf&FileName=Last%20Annual%20Inspection_Redacted-Rel.pdf - Onsite photo array-courtesy of the first responders (item 5, PDF, 5 pages, 740 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13367424&FileExtension=pdf&FileName=Onsite%20Photo%20Array-Rel.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.