# NTSB FTW97LA225: Air Tractor AT-502A, N248LF, Chesterville, TX, June 13, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 13, 1997, 13:00 local (18:00 UTC) - Place: Chesterville, TX - Coordinates: 29.519388, -96.220016 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.5194&lon=-96.2200&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 31, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 20245 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW97LA225 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20245/pdf - Page: https://openairdocs.org/ntsb/FTW97LA225 ## Probable cause an undetermined malfunction/failure of the propeller reversing system. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Propeller failure/malfunction, landing - roll - propeller system/accessories,reversing system - undetermined (cause) - Loss of control - on ground/water, landing - roll - ground loop/swerve - intentional, pilot in command - Occurrence ## Analysis After landing about 200 feet beyond the approach end of the 2,600 foot runway, the pilot attempted to apply reverse power, 'but did not receive any reversing action.' After attempting full reverse, 'the prop sounded like it was going to flat pitch.' In an attempt to 'go around,' the pilot pushed the power lever to full forward, but did not get any response. Another attempt was made to apply reverse with no response. Approaching the departure end of the runway, the pilot applied left brake and intentionally ground looped the airplane to avoid hitting parked trucks adjacent to the end of the runway. Subsequently, the right main landing gear sheared and the airplane skidded into a ditch. External examination of the engine, engine accessory gearbox, and propeller assemblies did not reveal any obvious preimpact anomalies. No oil leaks were found in the propeller piston or the propeller governor assembly. All cockpit power control quadrant linkages were intact, and the reverse detent on the thrust lever operated normally when cycled. Teardown examination of the propeller assembly did not reveal any defects. The propeller governor did not show any abnormality during functional bench tests. ## Factual narrative On June 13, 1997, approximately 1300, central daylight time, an Air Tractor AT-502A agricultural airplane, N248LF, owned and operated by Lissie Flying Service, Lissie, Texas, was substantially damaged during landing roll out at a private agriculture airstrip, near Chesterville, Texas. The commercial pilot, sole occupant, was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the Title 14 CFR Part 137 aerial application flight. The pilot reported that he had just landed about 200 feet beyond the approach end of the northwest oriented 2,600 foot runway. About 2/3 to the end of the runway, he applied reverse power, "but did not receive any reversing action." After applying full reverse, "the prop sounded like it was going to flat pitch." In an attempt to "go around" he pushed the power lever to full forward, but did not get any response. Another attempt was made to apply reverse with no response. As the airplane approached the departure end of the runway, the pilot applied left brakes to intentionally ground loop to avoid hitting parked trucks at the departure end of the runway. Subsequently, the right main landing gear sheared and the airplane skidded into a ditch adjacent to the left side of the runway. On site examination of the airplane by a FAA inspector revealed that the right wing spar web was structurally damaged. External examination of the engine, engine accessory gearbox, and propeller assemblies did not reveal any obvious pre-impact anomalies. Further external examination of the propeller piston and the propeller governor did not reveal any oil leaks.[Note: Propeller blade pitch is actuated by oil pressure within the piston assembly] All cockpit power control quadrant linkages were found to be intact, and the reverse detent on the thrust lever housing operated normally when cycled. At the request of the NTSB investigator-in-charge, the operator coordinated a teardown of the propeller assembly, and a functional bench test of the propeller governor. The propeller assembly, which was overhauled approximately 6 months prior to the accident, did not reveal any defects during the teardown examination. The propeller governor, which was recently installed and had a total time since overhaul of 31.2 hours, did not show any abnormalities during the bench tests that would have contributed to the accident. However, it was noted in the test results that the underspeed setting @ 3,000 engine RPM, was found to be 1.5 PSI. According to manufacturer's specifications, the underspeed setting @ 3,000 RPM should be 4.0 PSI. According to the bench test technician, the lower underspeed PSI setting would not inhibit propeller reversing capability. ## Aircraft - Registration: [N248LF](https://openairdocs.org/deregistered/N248LF-2010-06-22), registration cancelled 2010-06-22, S/N 502A-0192, built 1992 (OpenAirDocs) - Reported make and model: Air Tractor AT-502A - Registry model: [Air Tractor AT-502A](https://openairdocs.org/model/air-tractor-at-502a) (registry code 0390306) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Engines: P&W PT6A-45A 1100 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Peter D. Gertson - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, April 1, 1997, 239 hours before - Departed: NONE - Airport: NONE, Private Airstrip, runway 27, 2,600 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; commercial; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 22,940 total, 3,000 in this make and model, 22,740 as pilot in command, 300 in the last 90 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F - Altimeter: 30.00 inHg ## 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 19970613014259A](https://openairdocs.org/incident/19970613014259A), Jun 13, 1997: Airtrc AT502A, Chesterville, TX, Substantial damage. No reverse thrust landing. Ground looped end of runway to avoid parked truck. No anomalies. Reverse thrust normal. (-23) the aircraft was in the process of… ## Other investigations on N248LF (1) 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. - [NTSB CEN09CA295](https://openairdocs.org/ntsb/CEN09CA295), May 8, 2009: Air Tractor AT502 (N248LF), Lisse, TX, substantial damage. Probable cause: A total loss of engine power for undetermined reasons. 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.