# NTSB CEN20CA184: Rhoads, Larry E Sopwith Baby, N41LR, Lee's Summit, MO, May 19, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Data collection · Final report - Date: May 19, 2020, 16:45 local (21:45 UTC) - Place: Lee's Summit, MO - Coordinates: 38.95972, -94.373886 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.9597&lon=-94.3739&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 101310 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20CA184 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101310/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101310 - Page: https://openairdocs.org/ntsb/CEN20CA184 ## Probable cause The airplane builder's improper installation of the lower right wing which resulted in an uncommanded left roll and the subsequent loss of control. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Wing structure: flight surfaces (wing)](https://openairdocs.org/ntsb-findings/01035750): Aircraft › Aircraft structures · Design (probable cause); cases with it: [Rhoads Larry E SOPWITH BABY, 1 case](https://openairdocs.org/ntsb-findings/01035750/cases.md?model=05638QH), [All aircraft, 20 cases](https://openairdocs.org/ntsb-findings/01035750/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Rhoads Larry E SOPWITH BABY, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05638QH), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Rhoads Larry E SOPWITH BABY, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=05638QH), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) ## Analysis The pilot departed on the airplane's initial test flight in a tailwheel-equipped biplane. At the speed when the tailwheel lifted from the runway, the airplane began an uncommanded left roll. The pilot attempted to arrest the roll moment but was unsuccessful. He aborted the takeoff but lost control of the airplane as it settled down in a crab. The airplane exited the side of the runway and resulted in the failure of the left landing gear, and subsequent nose over of the airplane. The lower left wing sustained substantial damage. The airplane builder conducted a post-accident examination and reported that the right wing had a different "angle-of-attack" then the other wings, due to a construction error. This difference likely resulted in the uncommanded left roll during takeoff. This rolling tendency was not detected during the previous four high-speed taxi tests.. ## Aircraft - Registration: [N41LR](https://openairdocs.org/aircraft/N41LR), registered now, S/N 001, built 2019 (OpenAirDocs) - Reported make and model: Rhoads, Larry E Sopwith Baby - Registry model: [Rhoads Larry E SOPWITH BABY](https://openairdocs.org/model/rhoads-larry-e-sopwith-baby) (registry code 05638QH) (OpenAirDocs) - Registry engine: [Rotec R3600](https://openairdocs.org/engine/rotec-r3600) (registry code 55610, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 001 - Year built: 2019 - Engines: Rotec 3600 150 horsepower reciprocating - Damage: Substantial damage - Flight: Flight test, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, January 31, 2020 - Departed: LXT, Lee's Summit, MO - Destination: LXT, Lee's Summit, MO - Airport: LXT, Lee'S Summit Muni, runway 36, 5,501 × 100 ft, concrete - Equipment: Angle of attack indicator, ADS-B, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review February 12, 2020; seat: left; restraint: 3-point; flight hours: 2,186 total, 0.1 in this make and model, 1,345 as pilot in command, 4 in the last 90 days, 3 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 52 °F - Altimeter: 29.94 inHg - Observed at: KLXT ## 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 20200519006859A](https://openairdocs.org/incident/20200519006859A), May 19, 2020: Rhoads Larry E SOPWITH BABY, Lee'S Summit, MO, Substantial damage. On may 19, 2020 at or around 1645 while attempting initial takeoff in N41LR, an experimental wwi replica aircraft, the pilot states he experienced a severe… ## Docket (3 files) The files NTSB released with the investigation on July 24, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101310. 2.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40485554&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Additional Information (item 2, .PDF, 164 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40485555&FileExtension=.PDF&FileName=Additional%20Information-Master.PDF - Photos (item 3, .PDF, 132 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40485556&FileExtension=.PDF&FileName=Photos-Master.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.