# NTSB DFW05LA081: Piper PA-23-250, N33AC, Westport, OK, March 5, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 5, 2005, 17:15 local (23:15 UTC) - Place: Westport, OK - Coordinates: 36.222221, -96.346107 - Nearby events: https://openairdocs.org/map.md?lat=36.2222&lon=-96.3461&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 8, 2005 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 61108 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW05LA081 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61108/pdf - Page: https://openairdocs.org/ntsb/DFW05LA081 ## Probable cause The collapsing of the right main landing gear as a result of the failure of the scissors assembly. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Gear collapsed, landing - roll - landing gear,main gear strut scissors - failure (cause) - Loss of control - on ground/water, landing - roll - directional control - not possible - On ground/water collision with object, landing - roll - object - tree(s) ## Analysis The 5,500-hour pilot reported that during the landing roll on runway 3 (2,900-foot long and 42-foot wide asphalt runway), the right main landing gear collapsed. Subsequently, the airplane veered to the right, exited the runway, and traveled down a rock embankment, striking multiple small trees. Examination of the right main landing gear revealed that the right main landing gear Torque Link Assembly P/N 31805-06 (scissors assembly) was missing the following: bolt (P/N 751 370), cotter pin (P/N 424 052), castle nut (P/N 404 101), washer (P/N 407 565), and bushing (P/N 751 367). ## Factual narrative On March 5, 2005, approximately 1715 central standard time, a Piper PA-23-250 twin-engine airplane, N33AC, registered to and operated by the pilot, was substantially damaged when the right main landing gear collapsed during the landing roll at the Westport Airport (4F1), near Westport, Oklahoma. The private pilot, sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The local flight originated from 4F1 approximately 1600. The 5,500-hour pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that during the landing roll on runway 3 (2,900-foot long and 42-foot wide asphalt runway), the right main landing gear collapsed. Subsequently, the airplane veered to the right, exited the runway, and traveled down a 12-foot rock embankment, striking multiple small trees. The airplane came to rest upright approximately 60 feet to the right of the runway. Examination of the airplane by an Federal Aviation Administration Inspector (FAA), who responded to the accident site, revealed that the left wing was partially sheered-off at the wing root. The trunk of a tree was found embedded in the leading edge of the right wing. Further examination showed that the right main landing gear Torque Link Assembly P/N 31805-06 (scissors assembly) was missing the following: bolt (P/N 751 370), cotter pin (P/N 424 052), castle nut (P/N 404 101), washer (P/N 407 565), and bushing (P/N 751 367). The last annual inspection was completed on May 20, 2004, about 45.6 hours prior to the mishap. ## Aircraft - Registration: [N33AC](https://openairdocs.org/deregistered/N33AC-2008-02-13), registration cancelled 2008-02-13, S/N 27-7405299, built 1973 (OpenAirDocs) - Reported make and model: Piper PA-23-250 - Registry model: [Piper PA-23-250](https://openairdocs.org/model/piper-pa-23-250) (registry code 7102308) (OpenAirDocs) - Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 27-7405299 - Airframe hours: 4150 - Engines: Lycoming IO-540-C4B5 250 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Edward Allen Felmlee - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 20, 2004, 45.6 hours before - Departed: 4F1, Westport, OK - Destination: 4FI, Westport, OK - Airport: 4F1, Westport Airport, runway 3, 2,900 × 42 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 81; injuries: none; private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; last flight review December 28, 2004; seat: left; flight hours: 5,500 total, 2,500 in this make and model, 30 in the last 90 days, 10 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 32 °F - Altimeter: 30.19 inHg - Observed at: RVS, 20 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 20050305002009A](https://openairdocs.org/incident/20050305002009A), Mar 5, 2005: Piper PA23250, Westport, OK, Destroyed. (-23) The aircraft was landing on runway 03 at 4F1. During the landing roll the pilot and witnesses reported the right main landing gear collapsed. 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.