# NTSB WPR25LA074: Piper PA-18-150, N4644Y, Red Rock, MT, January 6, 2025 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: January 6, 2025, 14:30 local (21:30 UTC) - Place: Red Rock, MT · North of 4U9 - Coordinates: 44.88288, -112.71296 - Nearby events: https://openairdocs.org/map.md?lat=44.8829&lon=-112.7130&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Nose over/nose down](https://openairdocs.org/ntsb-events/096) - 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): 199517 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR25LA074 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/199517/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=199517 - Page: https://openairdocs.org/ntsb/WPR25LA074 ## Probable cause The pilot's failure to maintain directional control during takeoff, which resulted in an impact with deep snow and vegetation. ## 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; 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: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-18-150, 98 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=7101828), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Object/animal/substance: snow/ice](https://openairdocs.org/ntsb-findings/03022060): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Piper PA-18-150, 2 cases](https://openairdocs.org/ntsb-findings/03022060/cases.md?model=7101828), [All aircraft, 67 cases](https://openairdocs.org/ntsb-findings/03022060/cases.md) - [Object/animal/substance](https://openairdocs.org/ntsb-findings/03022000): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Piper PA-18-150, 3 cases](https://openairdocs.org/ntsb-findings/03022000/cases.md?model=7101828), [All aircraft, 224 cases](https://openairdocs.org/ntsb-findings/03022000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Nose over/nose down](https://openairdocs.org/ntsb-events/096) (defining event); cases with it: [Piper PA-18-150, 83 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7101828), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot of a tail wheel equipped airplane reported that due to carburetor icing he was forced to land on a mountain ridge. After clearing snow and sagebrush to make a runway, the pilot attempted to depart, but during the takeoff roll the airplane veered right into deep snow and sagebrush. The airplane nosed over and came to rest inverted, which resulted in substantial damage to the wing struts, rudder and vertical stabilizer. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N4644Y](https://openairdocs.org/aircraft/N4644Y), registered now, S/N 18-8945, built 1971 (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: 18-8945 - Year built: 1971 - Engines: LYCOMING O-320 SERIES 150 horsepower reciprocating - Damage: Substantial damage - Flight: Public aircraft - state, Public use - Operator: State Of Montana - Registered owner: State Of Montana - Airworthiness certificate: Standard, Normal - Departed: DLN, Dillon, MT, MT - Flight plan: VFR - Equipment: Electronic flight bag or handheld device, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review August 28, 2023; seat: front; flight hours: 3,290 total, 1,230 in this make and model, 3,225 as pilot in command, 37 in the last 90 days, 31 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft overcast - Temperature: 30 °F, dew point 18 °F - Altimeter: 30.15 inHg - Observed at: KDLN, 23 nm away - METAR: KDLN 060853Z AUTO 00000KT 10SM OVC100 M07/M08 A3015 RMK AO2 SLP257 T10721083 58003 ## 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 20250106000119A](https://openairdocs.org/incident/20250106000119A), Jan 6, 2025: Piper PA-18-150, Butte, MT, Substantial damage. Aircraft overturned while attempting to take off from an unimproved runway after an off airport landing the day before due to suspected carburetor ice. ## Docket (2 files) The files NTSB released with the investigation on April 22, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=199517. 2.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18233312&FileExtension=pdf&FileName=6120%20WPR25LA074%20Redrock,%20MT%20N4644Y_Redacted-Rel.pdf - Photos (item 2, PDF, 2 pages, 704 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18247978&FileExtension=pdf&FileName=Docket%20pic%20array%20WPR25LA074-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.