# NTSB CEN21LA333: Boeing E75, N51CF, Baraboo, WI, July 23, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: July 22, 2021, 19:00 local (Jul 23, 2021, 00:00 UTC) - Place: Baraboo, WI - Coordinates: 43.524428, -89.777409 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.5244&lon=-89.7774&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - 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 Milwaukee FSDO - NTSB case key (mKey): 103529 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA333 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103529/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103529 - Page: https://openairdocs.org/ntsb/CEN21LA333 ## Probable cause The pilot’s failure to maintain clearance from the fence while on final approach. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: monitoring environment](https://openairdocs.org/ntsb-findings/02021545): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Boeing E75, 1 case](https://openairdocs.org/ntsb-findings/02021545/cases.md?model=1380120), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Boeing E75, 2 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=1380120), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Awareness of condition; cases with it: [Boeing E75, 1 case](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=1380120), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Boeing E75, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=1380120), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot of the biplane reported that while on the final approach for the grass runway, he was maneuvering the airplane for landing to touchdown at the runway threshold markers. The airplane impacted an unmarked gray metal chain-link fence, about 8 ft tall, located about 250 ft from the runway threshold markers. The pilot reported the “fence blended in pretty well with the grass.” The airplane came to rest inverted on the runway and sustained substantial damage to both wings and the empennage. The pilot stated that the visibility at the time of the accident was “good,” and the lighting was “a little unusual from all the fires out west and I never saw the fence.” The pilot reported there were no preimpact mechanical malfunctions or failures with the airframe and the engine that would have precluded normal operation. ## Aircraft - Registration: [N51CF](https://openairdocs.org/deregistered/N51CF-2022-07-23), registration cancelled 2022-07-23, S/N 75-5604, built 1941 (OpenAirDocs) - Reported make and model: BOEING E75 - Registry model: [Boeing E75](https://openairdocs.org/model/boeing-e75) (registry code 1380120) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 75-5604 - Year built: 1941 - Airframe hours: 3677 - Engines: Pratt & Whitney R-985 Series 450 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 25, 2021 - Departed: MCW, Mason City, IA - Destination: Same as departure - Airport: DLL, Baraboo-Wisconsin Dells Rgnl, runway 14/32, 2,746 × 100 ft, grass/turf - Equipment: Handheld GPS, Electronic flight bag or handheld device, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review June 25, 2021; seat: rear; restraint: 4-point; flight hours: 3,032 total, 134 in this make and model, 2,883 as pilot in command, 40 in the last 90 days, 33 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 68 °F - Altimeter: 30.09 inHg - Observed at: KDLL - METAR: KDLL 222355Z AUTO 20003KT 10SM CLR 27/20 A3009 RMK AO2 T02650195 10280 20252 ## 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 20210722011349A](https://openairdocs.org/incident/20210722011349A), Jul 22, 2021: Boeing E75, Baraboo, WI, Substantial damage. Aircraft N51CF came in low and struck the airport fence on short final to runway 14 and flipped over 2.5 times. Aircraft came to rest on airport property 100… ## Docket (3 files) The files NTSB released with the investigation on August 27, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103529. 4.3 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12518992&FileExtension=pdf&FileName=NTSB%20Form%206120_1%20CEN21LA333%20Redacted-Rel.pdf - Accident photographs (item 2, PDF, 4 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12519276&FileExtension=pdf&FileName=Accident%20Photos-Rel.pdf - Airport documents (item 3, PDF, 2 pages, 253 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12518819&FileExtension=pdf&FileName=Airport%20Documents-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.