# NTSB WPR21LA137: Piper PA-18-150, N82479, Three Forks, MT, March 17, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: March 17, 2021, 12:45 local (18:45 UTC) - Place: Three Forks, MT - Coordinates: 45.878388, -111.56889 - Nearby events: https://openairdocs.org/map.md?lat=45.8784&lon=-111.5689&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 102784 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA137 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102784/pdf - Page: https://openairdocs.org/ntsb/WPR21LA137 ## Probable cause The pilot’s improper landing flare, which resulted in a loss of directional control, runway excursion and impact with terrain. ## 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-18-150, 160 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7101828), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-18-150, 8 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md?model=7101828), [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot; cases with it: [Piper PA-18-150, 51 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7101828), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Piper PA-18-150, 109 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=7101828), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) ## Analysis The pilot in the tailwheel equipped airplane reported that, during the landing, the airplane bounced, and he was unable to maintain directional control. The airplane departed the runway and impacted a berm. The right wing impacted the ground and was substantially damaged. The pilot reported that there were no mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N82479](https://openairdocs.org/aircraft/N82479), registered now, S/N 18-7709155, built 1977 (OpenAirDocs) - Reported make and model: PIPER PA-18-150 - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-7709155 - Year built: 1977 - Airframe hours: 1443 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: 100 hour, January 18, 2021, 9 hours before - Departed: 7S1, Twin Bridges, MT - Destination: 9S5, Three Forks, MT - Airport: 9S5, Three Forks, runway 20, 5,099 × 60 ft, asphalt - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: none; private; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; seat: front; restraint: 4-point; flight hours: 2,330 total, 437 in this make and model, 2,049 as pilot in command, 34 in the last 90 days, 13 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 52 °F, dew point 19 °F - Altimeter: 30.10 inHg - Observed at: BZN, 24 nm away ## 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 20210317002609A](https://openairdocs.org/incident/20210317002609A), Mar 17, 2021: Piper PA-18-150, Three Forks, MT, Substantial damage. On 17 April 2021 at 1245 local, N82479 a Piper PA12 piloted by [privacy data omitted] lost control on landing rwy 21 at Three Forks Montana airport (9S5). The… 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.