# NTSB CEN25LA264: Alon A2, N6557Q, Pipestone, MN, July 20, 2025 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: July 20, 2025, 14:15 local (19:15 UTC) - Place: Pipestone, MN · Located in cornfield adjacent to airport property. - Coordinates: 43.98472, -96.30348 - Nearby events: https://openairdocs.org/map.md?lat=43.9847&lon=-96.3035&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 9, 2026 - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 200584 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN25LA264 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/200584/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=200584 - Page: https://openairdocs.org/ntsb/CEN25LA264 ## Probable cause The failure of the left brake to release due to corrosion and pitting of the caliper piston and bore, which resulted in a runway excursion. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: master cylinder/brake valve](https://openairdocs.org/ntsb-findings/01023243): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Alon A2, 1 case](https://openairdocs.org/ntsb-findings/01023243/cases.md?model=0540102), [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/01023243/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Alon A2, 4 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=0540102), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) ## Analysis The pilot reported that when the wheels touched down during landing the airplane pulled hard to the left and departed the runway despite his control inputs to correct the airplane’s direction of travel. The airplane nose landing gear collapsed during the runway excursion and the airplane came to rest inverted in the adjacent cornfield. The wings and empennage sustained substantial damage. After the accident a bystander attempted to turn the left wheel of the airplane and told the pilot he could barely move it. Later when the pilot tried to move the left wheel it turned freely. A post-accident examination of the airplane showed that the brake caliper pistons and piston bores for both main landing gear were corroded and pitted. It is likely the left brake caliper failed to release after being used during the landing due to the corroded brake components. ## Aircraft - Registration: [N6557Q](https://openairdocs.org/aircraft/N6557Q), registered now, S/N A-57, built 1965 (OpenAirDocs) - Reported make and model: ALON A2 - Registry model: [Alon A2](https://openairdocs.org/model/alon-a2) (registry code 0540102) (OpenAirDocs) - Registry engine: [Continental C90 series](https://openairdocs.org/engine/continental-c90-series) (registry code 17009, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: A-57 - Year built: 1965 - Airframe hours: 2485 - Engines: Continental O-200-A 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 1, 2025 - Departed: RAP, Rapid City, SD - Destination: Same as departure - Airport: PQN, Pipestone Muni, runway 09, 2,539 × 196 ft, grass/turf - Equipment: Electronic multifunction display, Electronic primary flight display, Satellite tracking device, Stall warning system, ADS-B, Auto-pilot, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 73; injuries: none; private; airplane ratings: single-engine land; medical: basicmed, with waivers/limitations; last flight review August 26, 2024; seat: left; restraint: 3-point; flight hours: 1,245 total, 1,175 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: 2,400 ft broken - Temperature: 79 °F, dew point 73 °F - Altimeter: 29.94 inHg - Observed at: KMDS, 34 nm away - METAR: METAR KMDS 201915Z AUTO 13011G17KT 10SM BKN024 26/23 A2994 RMK AO2 TSNO= ## 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 20250720012419A](https://openairdocs.org/incident/20250720012419A), Jul 20, 2025: Alon A2, Pipestone, MN, Substantial damage. The PIC approached the grass runway, touched down, and the aircraft pulled hard left. The pilot applied full right rudder and full right aileron but was unable… ## Other investigations on N6557Q (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 CHI72DET24](https://openairdocs.org/ntsb/CHI72DET24), Apr 16, 1972: Alon A-2 (N6557Q), Mentone, IN, substantial damage ## Docket (3 files) The files NTSB released with the investigation on January 9, 2026, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=200584. 7.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 3.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19240462&FileExtension=pdf&FileName=CEN25LA264%20-%206120_1_Redacted-Rel.pdf - Photos (item 2, PDF, 6 pages, 5 photos, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19240472&FileExtension=pdf&FileName=CEN25LA264%20-%20PHOTOS-Rel.pdf - Wreckage examination (item 3, PDF, 12 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19725854&FileExtension=pdf&FileName=CEN25LA264%20-%20ACFT%20-%20Wreckage%20Exam-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.