# NTSB CEN10IA030: Curtiss Wright P-40E, N4420K, Lincoln, NE, October 24, 2009 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: October 24, 2009, 10:20 local (15:20 UTC) - Place: Lincoln, NE - Coordinates: 40.850833, -96.759162 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.8508&lon=-96.7592&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 19, 2010 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Adminisrtaton - NTSB case key (mKey): 74960 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10IA030 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74960/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74960 - Page: https://openairdocs.org/ntsb/CEN10IA030 ## Probable cause The right landing gear's partial retraction during landing due to paint contamination of the landing gear handle detent. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Curtiss Wright P-40E, 1 case](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=2622203), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/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: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Curtiss Wright P-40E, 1 case](https://openairdocs.org/ntsb-events/094/sequence.md?model=2622203), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis Upon touchdown, the World War II era tailwheel-equipped airplane experienced an uncontrollable swerve as the right main landing gear began to collapse. As the right main gear exited the edge of the runway, the airplane rocked forward onto its nose and the propeller and left wing tip impacted the ground. The airplane rocked back and came to rest partially off the runway in an upright and right wing low position. An examination of the landing gear retraction system revealed that the landing gear handle detent was contaminated with paint. Subsequently, the landing gear handle did not stay in the detent which resulted in the right landing gear downlock pin to partially retract followed by the partial retraction of the right main landing gear. ## Factual narrative Upon touchdown, the World War II era tailwheel-equipped airplane experienced an uncontrollable swerve as the right main landing gear began to collapse. As the right main gear exited the edge of the runway, the airplane rocked forward onto its nose and the propeller and left wing tip impacted the ground. The airplane rocked back and came to rest partially off the runway in an upright and right wing low position. An examination of the landing gear retraction system revealed that the landing gear handle detent was contaminated with paint. Subsequently, the landing gear handle did not stay in the detent which resulted in the right landing gear downlock pin to partially retract, followed by the partial retraction of the right main landing gear. ## Aircraft - Registration: [N4420K](https://openairdocs.org/aircraft/N4420K), registered now, S/N AK75315134 (OpenAirDocs) - Reported make and model: CURTISS WRIGHT P-40E - Registry model: [Curtiss Wright P-40E](https://openairdocs.org/model/curtiss-wright-p-40e) (registry code 2622203) (OpenAirDocs) - Category: Airplane - Serial number: AK75315134 - Engines: Allison V-1710-39 1425 horsepower reciprocating - Damage: Minor damage - Flight: Personal, Part 91 - Operator: Minnesota Airways LLC - Registered owner: Minnesota Airways LLC - Airworthiness certificate: Special, Experimental (Special) - Departed: GDB, Granite Falls, MN - Destination: LNK, Lincoln, NE - Airport: LNK, Lincoln Municipal Airport, runway 17, 5,400 × 100 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review October 21, 2008; seat: single; flight hours: 18,850 total, 140 in this make and model, 18,850 as pilot in command, 30 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 39 °F, dew point 36 °F - Altimeter: 29.78 inHg - Observed at: LNK ## 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 20091024051459A](https://openairdocs.org/incident/20091024051459A), Oct 24, 2009: Curtiss Wri P-40E, Lincoln, NE, Substantial damage. Pilot landed on runway 17, told to turn left on e or n, made a sharp right turn off runway 17, right main gear collapsed. ## Other investigations on N4420K (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 WPR23FA244](https://openairdocs.org/ntsb/WPR23FA244), Jun 27, 2023: Curtiss Wright P-40E (N4420K), Hamilton, MT, substantial damage, 1 fatal. Probable cause: A loss of engine power for undetermined reasons. ## Docket (1 files) The files NTSB released with the investigation on December 14, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74960. 115 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40322523&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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.