# NTSB WPR21LA079: Piper PA-20-135, N1571A, Riverside, UT, January 1, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: December 31, 2020, 17:00 local (Jan 1, 2021, 00:00 UTC) - Place: Riverside, UT - Coordinates: 41.78007, -112.14178 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.7801&lon=-112.1418&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Western Pacific Region - NTSB case key (mKey): 102492 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA079 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102492/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102492 - Page: https://openairdocs.org/ntsb/WPR21LA079 ## Probable cause A failure of the throttle control during a landing roll, which resulted in a loss of control and collision with a fence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine controls: power lever](https://openairdocs.org/ntsb-findings/01057603): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Piper PA-20-135, 1 case](https://openairdocs.org/ntsb-findings/01057603/cases.md?model=7102010), [All aircraft, 95 cases](https://openairdocs.org/ntsb-findings/01057603/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-20-135, 4 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7102010), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Object/animal/substance: fence/fence post](https://openairdocs.org/ntsb-findings/03022047): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Piper PA-20-135, 1 case](https://openairdocs.org/ntsb-findings/03022047/cases.md?model=7102010), [All aircraft, 313 cases](https://openairdocs.org/ntsb-findings/03022047/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Piper PA-20-135, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=7102010), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Landing-landing roll: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Piper PA-20-135, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=7102010), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported that, following a “smooth” landing, he reduced power, but the throttle control broke and the engine advanced to full power. The pilot immediately placed the mixture control in the lean position, but the airplane overran the runway onto a road. The left wing of the airplane subsequently contacted a fence, the airplane rotated left 180° and impacted a fencepost before it came to rest. The right main landing gear collapsed, and the airplane sustained substantial damage to the wings. ## Aircraft - Registration: [N1571A](https://openairdocs.org/deregistered/N1571A-2023-02-18), registration cancelled 2023-02-18, S/N 20-787, built 1951 (OpenAirDocs) - Reported make and model: PIPER PA-20-135 - Registry model: [Piper PA-20-135](https://openairdocs.org/model/piper-pa-20-135) (registry code 7102010) (OpenAirDocs) - Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 20-787 - Year built: 1951 - Airframe hours: 4689.8 - Engines: LYCOMING O-320 A1A 140 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 20, 2020, 22 hours before - Departed: GNG, Gooding, ID - Destination: Same as departure - Flight plan: VFR - Airport: PRIVATE, Private, runway 17, 2,000 × 30 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review March 5, 2020; seat: left; restraint: 4-point; flight hours: 338.7 total, 40.2 in this make and model, 286.1 as pilot in command, 58.8 in the last 90 days, 36.6 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 6 knots - Visibility: 3 statute miles - Temperature: 27 °F, dew point 23 °F - Altimeter: 30.14 inHg - Observed at: KLGU, 13 nm away - METAR: KLGU 312353Z AUTO 01006KT 3SM BR OVC030 M03/M05 A3014 RMK AO2 T10281050 ## Docket (2 files) The files NTSB released with the investigation on September 1, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102492. 5.3 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 4.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11792987&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Accident photograph (item 2, PDF, 1 page, 552 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11793490&FileExtension=pdf&FileName=Accident%20Photographs-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.