# NTSB CEN23LA250: Champion 7EC, N80461, Waunakee, WI, June 21, 2023 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: June 21, 2023, 13:30 local (18:30 UTC) - Place: Waunakee, WI - Coordinates: 43.184189, -89.45263 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.1842&lon=-89.4526&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA Milwaukee FSDO - NTSB case key (mKey): 192417 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA250 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192417/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192417 - Page: https://openairdocs.org/ntsb/CEN23LA250 ## Probable cause A total loss of engine power during the initial takeoff climb due to a worn manual fuel primer pump locking mechanism, which resulted in an unlocked primer and an overly rich fuel mixture. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuel system](https://openairdocs.org/ntsb-findings/01022800): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Champion 7EC, 1 case](https://openairdocs.org/ntsb-findings/01022800/cases.md?model=21101NM), [All aircraft, 181 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md) - [Fuel system](https://openairdocs.org/ntsb-findings/01022800): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Champion 7EC, 1 case](https://openairdocs.org/ntsb-findings/01022800/cases.md?model=21101NM), [All aircraft, 181 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md) - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Champion 7EC, 1 case](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=21101NM), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Champion 7EC, 2 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=21101NM), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Champion 7EC, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=21101NM), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot purchased the airplane on the day of the accident and was planning to fly it to another airport. On the morning of the accident, a mechanic completed an annual inspection on the airplane. During the preflight inspection and the runup, no anomalies were noticed by the pilot. During the initial takeoff climb, the pilot noticed a decrease in the engine rpm. The pilot was unable to maintain altitude, and he was unable to identify what caused the partial loss of engine power. Shortly thereafter, the engine sustained a total loss of engine power, and the pilot performed a forced landing. Upon touchdown to a residential road, the airplane impacted a tree and an unoccupied motor vehicle. The airplane came to rest upright in the rear of another unoccupied motor vehicle. The airplane sustained substantial damage to the right wing and the fuselage. Postaccident examination of the airplane revealed significant wear of the locking mechanism on the manual fuel primer pump: only a narrow portion of the retaining lip was left to engage with the retaining pin. It is likely that a slight movement or vibration caused the retaining pin to move around the small piece of retaining lip that remained, resulting in the fuel primer pump becoming unlocked and extending. The spark plugs were found in a carbon fouled condition, consistent with an overly rich mixture. The fuel primer pump position and the condition of the spark plugs indicate that the total loss of engine power was likely due to an overly rich mixture resulting from excess fuel being pulled through the fuel pump primer and into the engine’s intake system when power was applied. ## Factual narrative On June 21, 2023, about 1330 central daylight time, a Champion 7EC airplane, N80461, sustained substantial damage when it was involved in an accident near Waunakee, Wisconsin. The pilot and the passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot purchased the airplane earlier on the day of the accident and was planning to fly it to the Brennand Airport (79C), Neenah, Wisconsin. On the morning of the accident, a mechanic completed an annual inspection on the airplane. Before the departure from the Waunakee Airport (6P3), Waunakee, Wisconsin, the pilot added 10.7 gallons of 100 low-lead fuel. During the preflight inspection and the runup, no anomalies were noticed by the pilot. During the initial climb from runway 9, the pilot noticed a decrease in engine rpm. The pilot was unable to maintain altitude, and he was unable to identify what caused the partial loss of engine power. Shortly thereafter, the engine sustained a total loss of power, and the pilot performed a forced landing. Upon touchdown to a residential road, the airplane impacted a tree and an unoccupied motor vehicle. The airplane came to rest upright in the rear of another unoccupied motor vehicle, and the two occupants were able to egress from the airplane without further incident. There were no injuries to persons on the ground. The airplane sustained substantial damage to the right wing and the fuselage. Postaccident examination of the airplane revealed that the airplane was equipped with a manually operated Kohler fuel primer pump (a piston-type pump). The fuel primer pump (part number K-2406-2 and no serial number listed) was found extended and unlocked, and the fuel primer pump would not lock. After a fuel primer pump is used to prime the engine during the starting sequence, it is supposed to be secured in and locked. Examination of all the spark plugs found them carbon-fouled, consistent with a rich mixture condition. A postaccident materials laboratory examination of the fuel primer pump revealed that the pump’s piston had a cylindrical pin perpendicular to the piston’s axis, which was used to lock the piston in the fully inserted position when not in use. The locking pin was about 0.093” diameter. The locking pin would normally kept captive by a retention lip on the pump housing end cap when the piston was fully inserted and turned either to the left or right. Examination of the end cap revealed that the retention lip on the end cap was worn away around most of its circumference, leaving only a 0.143-inch section of the retaining lip. Champion 7EC fuel system installation drawings #7-796 and #7-10002 (located in the Champion 7EC Operating and Service Manual), show that a Kohler fuel primer pump (part number K-2406-2) is used. However, the Champion 7EC Operating and Service Manual does not list any continued airworthiness guidance for the fuel primer pump. A review of the Federal AviationAdministration (FAA) Aviation Maintenance Technician Handbook - Airframe (FAA-H-8083-31B) found a description of how a manually operated fuel primer pump operates. However, a review of FAA Advisory Circular 43.13-1B Acceptable Methods, Techniques, and Practices – Aircraft Inspection and Repair, found no inspection guidance for manually operated fuel primer pumps. During the investigation, the FAA attempted to contact Kohler multiple times, with no response received. A search conducted by the FAA for any airworthiness information on the fuel primer pump revealed no such documents. ## Aircraft - Registration: [N80461](https://openairdocs.org/aircraft/N80461), registered now, S/N 7EC743 (OpenAirDocs) - Reported make and model: CHAMPION 7EC (NO SERIES EXISTS) - Registry model: [Champion 7EC](https://openairdocs.org/model/champion-7ec) (registry code 21101NM) (OpenAirDocs) - Registry engine: [Continental C90 series](https://openairdocs.org/engine/continental-c90-series) (registry code 17009, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 7EC-743 - Year built: 1960 - Airframe hours: 6165 - Engines: Continental Motors C90-12F 95 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 21, 2023, 0.1 hours before - Departed: 6P3, Waunakee, WI - Destination: 79C, Neenah, WI - Equipment: Electronic flight bag or handheld device, Onboard weather ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: minor; private; airplane ratings: single-engine land; medical: basicmed, without waivers/limitations; last flight review August 23, 2024; seat: front; restraint: 3-point; flight hours: 328.6 total, 68.1 in this make and model, 242 as pilot in command, 36 in the last 90 days, 27.8 in the last 30 days, 0.1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 11 knots, gusting 17 - Visibility: 10 statute miles - Temperature: 88 °F, dew point 61 °F - Altimeter: 30.11 inHg - Observed at: KMSN, 5 nm away - METAR: KMSN 211753Z 11011G17KT 10SM SCT060 31/16 A3011 RMK AO2 SLP192 T03060156 10311 20178 55006 ## 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 20230621018509A](https://openairdocs.org/incident/20230621018509A), Jun 21, 2023: Champion 7EC, Waunakee, WI, Substantial damage. On 06/21/2023 the pilot in command of [privacy data omitted] was departing Waunakee Airport (6P3) heading back to brennand airport (79C) when he had a loss of… ## Docket (10 files) The files NTSB released with the investigation on August 14, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192417. 18.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 5.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17340772&FileExtension=pdf&FileName=NTSB%20Form%206120_1_Redacted-Rel.pdf - Accident photographs (item 2, PDF, 3 pages, 392 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17340348&FileExtension=pdf&FileName=Accident%20Photographs-Rel.pdf - Pilot information (item 3, PDF, 4 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17339812&FileExtension=pdf&FileName=Pilot%20Information_Redacted-Rel.pdf - N80461 - airplane bill of sale (item 4, PDF, 1 page, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17340392&FileExtension=pdf&FileName=N80461%20-%20Airplane%20Bill%20of%20Sale_Redacted-Rel.pdf - N80461 - FAA examination report (item 5, PDF, 1 page, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17340453&FileExtension=pdf&FileName=N80461%20-%20FAA%20Examination%20Report-Rel.pdf - N80461 - recent airframe maintenance records (item 6, PDF, 4 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17340463&FileExtension=pdf&FileName=Recent%20Airframe%20Maintenance%20Records_Redacted-Rel.pdf - N80461 - recent engine maintenance records (item 7, PDF, 6 pages, 5.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17340325&FileExtension=pdf&FileName=Recent%20Engine%20Maintenance%20Records_Redacted-Rel.pdf - Materials laboratory factual report 24-008 (item 8, PDF, 6 pages, 4 photos, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17038213&FileExtension=pdf&FileName=Materials%20Laboratory%20Factual%20Report%2024-008-Rel.pdf - Kohler fuel primer pump (part number K-2406-2) - information (item 9, PDF, 1 page, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17340221&FileExtension=pdf&FileName=CEN23LA250%20Kohler%20Fuel%20Primer%20Pump%20-%20Memorandum-Rel.pdf - Champion 7EC operating and service manual - fuel primer pump excerpts (item 10, PDF, 3 pages, 701 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17340281&FileExtension=pdf&FileName=Champion%207EC%20Operating%20and%20Service%20Manual%20-%20Fuel%20Primer%20Pump%20Excerpts-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.