# NTSB CEN23FA320: Heath V-Strut, N9549, Oshkosh, WI, July 25, 2023 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Field · Final report - Date: July 25, 2023, 07:33 local (12:33 UTC) - Place: Oshkosh, WI - Coordinates: 43.992052, -88.552564 - Nearby events: https://openairdocs.org/map.md?lat=43.9921&lon=-88.5526&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA FSDO - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 192700 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23FA320 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192700/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192700 - Page: https://openairdocs.org/ntsb/CEN23FA320 ## Probable cause The pilot’s failure to maintain adequate airspeed and his exceedance of the airplane’s critical angle of attack, which resulted in an aerodynamic stall. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Price Christopher R HEATH V-STRUT, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=056131M), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Price Christopher R HEATH V-STRUT, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=056131M), [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. - [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Price Christopher R HEATH V-STRUT, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=056131M), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Initial climb: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Price Christopher R HEATH V-STRUT, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=056131M), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Price Christopher R HEATH V-STRUT, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056131M), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis Shortly after takeoff the pilot turned the airplane to avoid flying over the perpendicular runway. He reported that during the turn the airplane stopped climbing. The pilot aimed the airplane toward a field and attempted a forced landing. During the landing the airplane came to rest inverted, which resulted in substantial damage to the fuselage, empennage, and both wings. One witness stated that the airplane “looked sluggish,” with the nose of the airplane high. Several witnesses observed the left wing dip before the airplane descended below the tree line. Security video showed the left wing dropped and the airplane impacted the ground in a left-wing-low attitude. A postaccident examination of the engine, flight controls, and related systems revealed no mechanical failures or malfunctions that would have precluded normal operations. The splintered damage to the propeller blade was consistent with power and rotation at the time of impact. The pilot also reported that there was nothing mechanically wrong with the airplane at the time of the accident. Weather conditions at the time of the accident were conducive for serious icing at glide power. However, investigators were not able to determine if a partial loss of engine power due to the accumulation of carburetor icing during the ground taxi may have resulted in the loss of climb performance after takeoff. Given the witness description and the footage captured by the security camera, it is likely that the pilot failed to maintain adequate airspeed during the initial climb and turn, which resulted in the exceedance of the airplane’s critical angle of attack and an aerodynamic stall and a subsequent loss of control. ## Factual narrative On July 25, 2023, about 0733 central daylight time, a Heath V-Strut, N9549, was substantially damaged when it was involved in an accident at Wittman Regional Airport (OSH), Oshkosh, Wisconsin. The pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to one witness, after an extensive taxi, the airplane used about 200 ft of the runway to raise the tail of the airplane and about 1,000 ft of runway to become airborne. The witness stated that the airplane “looked sluggish” after takeoff, with the nose of the airplane high. The airplane started a left turn and then the left wing dipped, and the airplane descended below the tree line. Security video showed the airplane descend in a relatively flat pitch attitude. The left wing dropped, and the airplane impacted the ground in a left-wing-low attitude. The airplane continued forward onto the engine and propeller, nosed over, and came to rest inverted. According to the pilot he had just departed runway 36L and the climb rate was as expected. He turned the airplane 150° as instructed during his briefing to avoid runway 9/27. During the turn, the airplane stopped climbing and exhibited a decrease in performance. The pilot reported that he aimed the airplane toward a clearing past the trees and attempted a landing to the field. The airplane impacted a field adjacent to a commercial building about 1,000 ft east of runway 36L. The initial impact point contained fragmented wood consistent with the wing tip. The main wreckage was located just east of the initial impact point and included both wings, the empennage, fuselage, and engine (see Figure 1). Figure 1. Airplane wreckage. Aileron cable continuity was confirmed for both the right and left aileron, from the respective aileron inboard to the flight control stick. Control continuity was confirmed from the rudder inboard to the rudder pedals and from the elevator inboard to the flight control stick. The engine and propeller assembly remained attached to the fuselage at the firewall. The wooden Watson propeller blade was splintered consistent with impact on each side of the blade and contained grass and vegetation imbedded within the fracture. The splintered pieces of the propeller blade were found forward of the main wreckage. The gascolator and bowl remained attached at the firewall and contained fuel. Nothing mechanical was noted with the engine or related systems that would have precluded normal engine function. A review of the icing probability chart contained within FAA Special Airworthiness Information Bulletin CE-09-35 showed that the atmospheric conditions at the time of the accident were conducive for icing at glide power. ## Aircraft - Registration: [N9549](https://openairdocs.org/aircraft/N9549), registered now, S/N 151, built 2002 (OpenAirDocs) - Reported make and model: HEATH V-Strut - Registry model: [Price Christopher R HEATH V-STRUT](https://openairdocs.org/model/price-christopher-r-heath-v-strut) (registry code 056131M) (OpenAirDocs) - Registry engine: [Continental A40 series](https://openairdocs.org/engine/continental-a40-series) (registry code 17001, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 151 - Year built: 2002 - Airframe hours: 100 - Engines: Continental A-40 40 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, August 7, 2022 - Departed: KOSH, Oshkosh, WI - Airport: OSH, Wittman Regional Airport - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: serious; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review June 16, 2023; seat: single; restraint: lap only; flight hours: 213 total, 0.4 in this make and model, 144 as pilot in command, 8 in the last 90 days, 1.6 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 4 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 66 °F - Altimeter: 30.07 inHg - Observed at: KOSH - METAR: KOSH 251253Z 00000KT 4SM HZ CLR 22/19 A3007 RMK AO2 SLP169 T02170189 ## 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 20230725012099A](https://openairdocs.org/incident/20230725012099A), Jul 25, 2023: Price Christopher R HEATH V-STRUT, Oshkosh, WI, Substantial damage. On July 25, 2023, at 0740 CST, an experimental Heath V-Strut aircraft, [privacy data omitted] departed from Oshkosh WI (osh) to broadhead WI (C37). The pilot… ## Docket (7 files) The files NTSB released with the investigation on March 12, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192700. 120 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18319597&FileExtension=pdf&FileName=Pilot%20Operator%20Accident%20Report%20Form%20-%20CEN23FA320_Redacted-Rel.pdf - Examination summary statement (item 2, PDF, 3 pages, 103 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18320427&FileExtension=pdf&FileName=CEN23FA320%20Exam%20Summary%20Statement-Rel.pdf - Carburetor icing probability chart (item 3, PDF, 1 page, 380 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18305810&FileExtension=pdf&FileName=Carburetor%20Icing%20Probability%20Chart-Rel.pdf - Maintenance records excerpts (item 4, PDF, 3 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18295617&FileExtension=pdf&FileName=Maintenance%20Records%20Excerpts%20-%20N9549_Redacted-Rel.pdf - Witness statement (item 5, PDF, 1 page, 92 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18306816&FileExtension=pdf&FileName=witness%20statement_Redacted-Rel.pdf - Accident report photographs (item 6, PDF, 8 pages, 4.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18297938&FileExtension=pdf&FileName=Accident%20Report%20Photographs-Rel.pdf - Security video (item 7, MP4, 113 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18298621&FileExtension=mp4&FileName=CEN23FA320-Rel.mp4 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.