# NTSB CHI98LA234: American AA-1TW, N5643L, Point Lookout, MO, July 1, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 1, 1998, 13:30 local (18:30 UTC) - Place: Point Lookout, MO - Location: 36.6259° N, 93.2289° W: Placed by OpenAirDocs at M GRAHAM CLARK DOWNTOWN (PLK), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=36.6259&lon=-93.2289&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 10948 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI98LA234 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10948/pdf - Page: https://openairdocs.org/ntsb/CHI98LA234 ## Probable cause the failure of the tailwheel assembly due to corrosion. A factor associated with the accident was the overload failure of the right main landing gear. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - landing gear,tailwheel assembly - corroded (cause) - landing gear,tailwheel assembly - failure (cause) - directional control - not possible, pilot in command - On ground/water encounter with terrain/water, landing - roll - landing gear,main gear attachment - overload (contributing factor) ## Analysis The pilot stated that during the landing roll the tailwheel began to vibrate. The vibration increased and the airplane made a 'sharp yaw to the left.' After about 30 degrees of turn, the right landing gear attach bracket bolts sheared and the right wing contacted the runway. The airplane then skidded to the right side of the runway and exited the runway tail first. Inspection of the airplane revealed the right arm of the tailwheel had failed approximately 1' from the center of the arm. Corrosion was present on the factured surface. ## Factual narrative On July 1, 1998, at 1330 central daylight time, an American Yankee AA1-1TW, N5643L, impacted the terrain following a loss of directional control during a landing roll on runway 29 (3,539' x 100') at the Clark Airport, Point Lookout, Missouri. The ATP pilot and passenger were not injured and the airplane sustained substantial damage. The airplane was being operated as a personal flight under 14 CFR part 91 when the accident occurred. The flight originated Cape Girardeau, Missouri, at 1145. Visual meteorological conditions prevailed and no flight plan was filed. The pilot stated that during the landing roll, following a 3-point landing, the tailwheel began to vibrate. He reported the vibration increased and the airplane made a "sharp yaw to the left." After about 30 degrees of turn, the right landing gear attach bracket bolts sheared and the right wing contacted the runway. The airplane then skidded to the right side of the runway and exited the runway tail first. Inspection of the runway by the Clark Airport Operations Supervisor revealed tail wheel skid marks were present on the runway for a length in excess of 150 yards. Inspection of the airplane by an Inspector from the Kansas City Federal Aviation Administration Flight Standards District Office revealed the right arm of the tailwheel had failed approximately 1" from the center of the arm. Corrosion was present on the factured surface. ## Aircraft - Registration: [N5643L](https://openairdocs.org/aircraft/N5643L), registered now, S/N AA1-0043, built 1968 (OpenAirDocs) - Reported make and model: American Aviation Corp. (AAC) AA-1TW - Registry model: [American AA-1](https://openairdocs.org/model/american-aa-1) (registry code 0630610) (OpenAirDocs) - Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 43 - Airframe hours: 2236 - Engines: Lycoming O-235-C2C 108 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: James N. Mahle - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 1, 1998, 28 hours before - Departed: CGI, CAPE GIRARDEAU, MO - Destination: PLK, POINT LOOKOUT, MO - Airport: PLK, Clark Airport, runway 29, 3,539 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 26,445 total, 153 in this make and model, 25,112 as pilot in command, 206 in the last 90 days, 54 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 70 °F - Altimeter: 30.00 inHg - Observed at: SGF, 45 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 19980701015529A](https://openairdocs.org/incident/19980701015529A), Jul 1, 1998: Amrgen AA1, Point Lookout, MO, Substantial damage. Acft yawed to the left on landing and ground looped, other cirsumstances are unknown. Point Lookout,MO (.4)the pilot stated that during the landing roll 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.