# NTSB SEA00LA053: Piper PA-18-150, N2873Z, Three Forks, MT, March 16, 2000 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 16, 2000, 10:30 local (17:30 UTC) - Place: Three Forks, MT - Coordinates: 45.90929, -111.430801 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.9093&lon=-111.4308&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 9, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 48834 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA00LA053 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/48834/pdf - Page: https://openairdocs.org/ntsb/SEA00LA053 ## Probable cause The pilot's failure to maintain directional control of the tailwheel equipped airplane. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - roll - directional control - not maintained, pilot in command (cause) - Gear collapsed, landing - roll - landing gear,main gear - overload ## Analysis The pilot performed a 'stall' landing onto the aircraft's main gear, and then lowered the tailwheel to the ground after about 50 to 100 feet. According to the pilot, once the tailwheel was on the runway surface, it felt as if he had slight left brake applied, and the aircraft began drifting to the left. The pilot applied right rudder, but initially the aircraft kept drifting to the left. During his attempt to return the aircraft to the center of the runway, the airplane groundlooped to the right resulting in a collapsed of the left main landing gear. A post-accident inspection revealed no anomalies or malfunctions in the directional control systems or brake system. According to the pilot, the '...bottom line was failure to maintain directional control. ## Factual narrative On March 16, 2000, approximately 1030 mountain standard time, a Piper PA-18-150, N2873Z, experienced a gear collapse during the landing roll at Three Forks Airstrip, Three Forks, Montana. The commercial pilot and his passenger were not injured, but the aircraft, which was owned and operated by the pilot, sustained substantial damage. The CFR Part 91 personal pleasure flight, which departed Bozeman, Montana, about 45 minutes prior to the accident, was being operated in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation. According to the pilot, he "stalled" the aircraft onto the main gear and then lowered the tailwheel to the runway surface within 50 to 100 feet. He said that when the tailwheel touched down, the aircraft started pulling to the left as if he was applying "slight left brake." He applied significant right rudder in an attempt to return the aircraft to the center of the runway, but the aircraft still drifted to the left. As he was slowing, the aircraft suddenly turned to the right "...as though the left brake released or the tailwheel unlocked." Although he attempted to keep the aircraft aligned with the runway, the aircraft goundlooped to the right, resulting in the collapse of the left landing gear and damage to one of the wings. The pilot reported that there appeared to be no problems with or malfunction of any of the aircraft's directional control systems. The final line of his accident narrative stated, "Bottom line was failure to maintain directional control." The pilot also reported that he inspected the brakes after the accident and found "... no visible signs of malfunction." ## Aircraft - Registration: [N2873Z](https://openairdocs.org/aircraft/N2873Z), registered now, S/N 18-7036, built 1959 (OpenAirDocs) - Reported make and model: Piper PA-18-150 - Registry model: [Piper PA-18A 150](https://openairdocs.org/model/piper-pa-18a-150) (registry code 7101837) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-70-36 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Alfred T. Leroy - Airworthiness certificate: Special, Restricted (Special) - Departed: BZN, BOZEMAN, MT - Destination: 9S5 - Airport: 9S5, Three Forks, runway 20, 5,100 × 60 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; commercial; airplane ratings: single-engine land, multi-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 1,015 total, 784 in this make and model, 878 as pilot in command, 38 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 45 °F ## 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 20000316007969A](https://openairdocs.org/incident/20000316007969A), Mar 16, 2000: Piper PA18150, Three Forks, MT, No damage. (-23) Pilot stated that the aircraft began swerving to the left, and that he applied right rudder in an attempt to regain control. The swerve then reversed… 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.