# NTSB CEN22LA334: Van's RV-10, N4400K, Beaver Dam, WI, July 22, 2022 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: July 22, 2022, 16:47 local (21:47 UTC) - Place: Beaver Dam, WI · road / field - Coordinates: 43.483136, -88.827814 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.4831&lon=-88.8278&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: Minor injuries - Injuries: 1 minor, 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Lycoming Engines, FAA Milwaukee FSDO - NTSB case key (mKey): 105561 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA334 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105561/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105561 - Page: https://openairdocs.org/ntsb/CEN22LA334 ## Probable cause The improperly secured spark plug boot that resulted in smoke in the cockpit and a subsequent off-airport landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Ignition system: spark plugs/igniters](https://openairdocs.org/ntsb-findings/01057421): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [Black Star RV10, 1 case](https://openairdocs.org/ntsb-findings/01057421/cases.md?model=05639WF), [All aircraft, 38 cases](https://openairdocs.org/ntsb-findings/01057421/cases.md) - [Ignition system: spark plugs/igniters](https://openairdocs.org/ntsb-findings/01057421): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Black Star RV10, 1 case](https://openairdocs.org/ntsb-findings/01057421/cases.md?model=05639WF), [All aircraft, 38 cases](https://openairdocs.org/ntsb-findings/01057421/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Black Star RV10, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=05639WF), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Enroute: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150); cases with it: [Black Star RV10, 1 case](https://openairdocs.org/ntsb-events/150/sequence.md?model=05639WF), [All aircraft, 504 cases](https://openairdocs.org/ntsb-events/150/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Black Star RV10, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05639WF), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Black Star RV10, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=05639WF), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot of the airplane stated that after departure he heard a “very loud pop” from the engine and then saw smoke enter the cockpit. After the smoke cleared, he decided to perform an off-airport landing even though the engine continued to operate. He stated that he did not check the engine gauges to evaluate any anomalies. The pilot reported that the engine was operating after he heard the “loud pop” noise. During the approach to the field, the pilot added engine power to avoid hitting power lines. The airplane impacted a soccer goal, a streetlight, and a portable toilet, which resulted in substantial damage to the fuselage and right wing. Postaccident examination of the engine found the spark plug wire boot for the No. 6 cylinder was not connected to the spark plug and was found resting on the exhaust pipe. The rubber boot likely sustained thermal damage when it contacted the exhaust pipe; there were no other mechanical anomalies that would have precluded normal operation. A review of the maintenance records showed that 79.7 hours had accumulated on the engine since the last inspection, which was a condition inspection. It possible that the spark plug wire boot was not secured during the last maintenance work performed. Based on the available records, investigators were not able to determine why the spark plug wire boot was unsecured. ## Factual narrative On July 22, 2022, about 1647 central daylight time, a Van’s Aircraft RV-10 airplane, N4400K, sustained substantial damage when it was involved in an accident near Beaver Dam, Wisconsin. The pilot and one passenger sustained no injuries and one passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot reported that after take off from the Dodge County Airport (UNU), Juneau, Wisconsin, he heard a “very loud pop” from the experimental engine. Smoke entered the cockpit, but then the smoke cleared. The amount of smoke in the cockpit did not inhibit the pilot from performing visual functions. The pilot decided to perform an off-airport landing to a field. During the landing, the pilot was able to add power to the engine to avoid impacting power lines. After landing, the right wing impacted a soccer goal post. The airplane continued with the rollout and impacted a streetlight and a portable toilet. The airplane came to rest upright, and all three occupants were able to egress from the airplane without further incident. The airplane sustained substantial damage to the fuselage and the right wing. After the accident, the pilot reported that the engine was operating after he heard the “very loud pop;” however, he did not confirm this with the cockpit gauges or try to maintain level flight. A postaccident examination of the engine found that the lower spark plug wire boot for the No. 6 cylinder was not connected to the spark plug. The rubber boot had signatures consistent with the boot being burned on the outside of the 90° bend on the boot, and at the end of the boot, where the boot likely contacted the exhaust pipe it was resting on. The boot was burned enough so the electrode was able to contact the exhaust pipe. There were no other areas in the engine that showed signs of burning. Airframe to engine control continuity was established. Except for the burned spark plug wire boot, there were no preimpact mechanical malfunctions or failures that would have precluded normal operation of the engine. A review of the maintenance records showed that on March 22, 2022, a condition inspection was performed on the airplane. For the engine, a compression check was satisfactorily performed by a mechanic. For both the airframe and the engine, the entries stated that the condition inspection was performed in accordance with 14 CFR Part 43 Maintenance, Preventive Maintenance, Rebuilding, and Alteration, and the “manufacturer’s maintenance and inspection procedures.” According to information provided by the pilot, the engine had accumulated 79.7 hours since the inspection work. ## Aircraft - Registration: [N4400K](https://openairdocs.org/deregistered/N4400K-2024-01-20), registration cancelled 2024-01-20, S/N 42074, built 2021 (OpenAirDocs) - Reported make and model: Van's Aircraft RV-10 (NO SERIES) - Registry model: [Black Star RV10](https://openairdocs.org/model/black-star-rv10) (registry code 05639WF) (OpenAirDocs) - Registry engine: [Lycoming YIO-540 SERIE](https://openairdocs.org/engine/lycoming-yio-540-serie) (registry code 41779, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 42074 - Year built: 2021 - Airframe hours: 212.5 - Engines: Lycoming Engines YIO-540-D4A5 260 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, March 22, 2022, 79.7 hours before - Departed: UNU, Juneau, WI - Destination: OSH, Oshkosh, WI - Equipment: ADS-B, Stall warning system, Angle of attack indicator, Satellite tracking device, Onboard weather, Electronic primary flight display, Electronic multifunction display, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review September 22, 2021; seat: left; restraint: 4-point; flight hours: 783 total, 200 in this make and model, 783 as pilot in command, 28 in the last 90 days, 12 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 13 knots, gusting 20 - Visibility: 10 statute miles - Temperature: 86 °F, dew point 63 °F - Altimeter: 29.92 inHg - Observed at: KUNU, 6 nm away - METAR: KUNU 222135Z AUTO 22013G20KT 10SM SCT110 30/17 A2992 RMK AO2 T02950173 ## 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 20220722012929A](https://openairdocs.org/incident/20220722012929A), Jul 22, 2022: Black Star Aviation LLC RV10, Beaver Dam, WI, Substantial damage. On July 22, 2022 at approximately 16:45 local time, aircraft [privacy data omitted], a RV10 experimental amateur built aircraft, on a part 91 VFR flight landed… ## Docket (11 files) The files NTSB released with the investigation on February 7, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105561. 22.9 MB in all. - Accident photographs (item 1, PDF, 6 pages, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15980342&FileExtension=pdf&FileName=Accident%20Photographs-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 9 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15979690&FileExtension=pdf&FileName=NTSB%20Form%206120_1%20Redacted-Rel.pdf - FAA aviation safety inspector - statement (item 3, PDF, 5 pages, 398 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15980288&FileExtension=pdf&FileName=FAA%20ASI%20Statement%20Redacted-Rel.pdf - Airplane flight logs and maintenance records (item 4, PDF, 6 pages, 9.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15980400&FileExtension=pdf&FileName=Airplane%20Flight%20Log%20and%20Maintenance%20Records%20Redacted-Rel.pdf - Pilot logbook excerpts (item 5, PDF, 1 page, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15980482&FileExtension=pdf&FileName=Pilot%20Logbook%20Excerpts%20Redacted-Rel.pdf - ADS-B data (google earth file) (item 6, KMZ, 28 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15971407&FileExtension=kmz&FileName=20220722_A54CFF_490252553-Rel.kmz - ADS-B data (microsoft excel file) (item 7, XLSX, 977 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15971957&FileExtension=xlsx&FileName=20220722_A54CFF_490252553_ADSB-Rel.xlsx - Electronic flight information system - specialist's factual report (item 8, PDF, 12 pages, 8 photos, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14975955&FileExtension=pdf&FileName=Electronic%20Flight%20Information%20System%20-%20Specialist%27s%20Factual%20Report-Rel.pdf - Electronic flight information system - specialist's factual - ATTACHMENT1 (item 9, CSV, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14976236&FileExtension=csv&FileName=Electronic%20Flight%20Information%20System%20-%20Specialist%27s%20Factual%20-%20Attachment1-Rel.csv - Release of aircraft wreckage, NTSB form 6120.15 (item 10, PDF, 1 page, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15971740&FileExtension=pdf&FileName=N4400K%20Retention-Release-of-Wreckage-Form%20Redacted-Rel.pdf - NTSB party member form - Lycoming engines (item 11, PDF, 1 page, 223 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15972075&FileExtension=pdf&FileName=NTSB%20Party%20Member%20Form%20-%20Lycoming%20Engines%20Redacted-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.