# NTSB CEN24LA356: Piper PA-12, N7878M, Cumberland, WI, September 12, 2024 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: September 12, 2024, 12:05 local (17:05 UTC) - Place: Cumberland, WI · Cornfield - Coordinates: 45.57707, -91.93196 - Nearby events: https://openairdocs.org/map.md?lat=45.5771&lon=-91.9320&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-descent: Fuel related](https://openairdocs.org/ntsb-events/190) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 18, 2026 - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration - Minneapolis FSDO - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 195116 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN24LA356 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/195116/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=195116 - Page: https://openairdocs.org/ntsb/CEN24LA356 ## Probable cause The total loss of engine power due to carburetor icing and the pilot’s delayed use carburetor heat in weather conditions conducive to carburetor icing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Piper PA-12, 6 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=7101202), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-12, 4 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md?model=7101202), [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-12, 2 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=7101202), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-descent: Fuel related](https://openairdocs.org/ntsb-events/190) (defining event); cases with it: [Piper PA-12, 3 cases](https://openairdocs.org/ntsb-events/190/sequence.md?model=7101202), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Piper PA-12, 7 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7101202), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot was conducting a personal flight when during cruise descent the engine began to sputter and suddenly lost power. He moved the throttle to full-forward and increased the mixture to full-rich, but the engine resumed operation only 5 to 10 seconds before it lost power a second time. The pilot reported that the airplane was at low altitude that required an immediate forced landing into a nearby cornfield. The airplane sustained substantial damage to the engine mounts, fuselage structure, and right wing. Examination of the airplane fuel system and the engine revealed no evidence of a preimpact mechanical malfunction. There was ample fuel recovered from the fuel tanks at the accident site, and there was no evidence of any water or particulate contamination of the fuel system. The weather conditions at the time of the accident were in the range of susceptibility for the formation of serious carburetor icing at glide engine power. According to a Federal Aviation Administration Special Airworthiness Information Bulletin, pilots should use carburetor heat while in weather conditions where carburetor icing is probable. When interviewed, the pilot acknowledged that he did not review a carburetor icing chart before the flight. However, he stipulated that he applied carburetor heat after the engine began sputtering. Based on the available information, the loss of engine power was likely due to carburetor ice accumulation. Additionally, the low altitude at which the loss of engine power occurred significantly reduced the amount of time available to the pilot to troubleshoot and restore engine power before the forced landing. ## Factual narrative On September 12, 2024, about 1205 central daylight time, a Piper PA-12 airplane, N7878M, was substantially damaged when it was involved in an accident near Cumberland, Wisconsin. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that the airplane was established in cruise flight at 2,100 ft mean sea level with the throttle set about 2,300 rpm and the mixture leaned to rich-of-peak when he entered a descent toward Cumberland Municipal Airport (CBE), Cumberland, Wisconsin. The pilot stated that he did not make any throttle or mixture control changes when he began his descent, and that the engine was using fuel from both wing fuel tanks. The pilot reported that about 5 miles from CBE, while in cruise descent the engine began to sputter and then suddenly lost power. He moved the throttle to full-forward and increased the mixture to full-rich, but the engine resumed operation only 5 to 10 seconds before it lost power a second time. The pilot reported the airplane was at a low altitude that required an immediate forced landing into a nearby cornfield. The airplane sustained substantial damage to the engine mounts, fuselage structure, and right wing. Examination of the airplane fuel system and the engine revealed no evidence of a preimpact mechanical malfunction. There was ample fuel recovered from the fuel tanks at the accident site, and there was no evidence of any water or particulate contamination of the fuel system. Internal engine and valve train continuity were confirmed as the crankshaft was rotated through the propeller flange. Compression and suction were noted on all four cylinders in conjunction with crankshaft rotation. A lighted borescope inspection of each cylinder did not reveal any anomalies with the cylinders, pistons, valves, valve seats. Both magnetos remained attached to their engine installation points and produced spark at each ignition lead. The upper spark plugs exhibited features consistent with normal engine operation. The engine oil sump contained ample oil, and the disassembled oil filter did not reveal any evidence of contamination. The carburetor fuel inlet screen exhibited no evidence of contamination. The throttle cable was broken at the clevis, but the carburetor throttle position remained in a wide-open position. The mixture control was found in the full-rich position, and the full-rich mechanical stop-pin was found fractured. The cockpit carburetor heat control was found turned off. Cable continuity was confirmed from the carburetor heat control to the airbox control; however, due to impact-related damage to the airbox, the carburetor heat valve could not move. A borescope was inserted into the damaged airbox and did not reveal any evidence of rubbing/scratching between the carburetor heat valve and the airbox. According to a carburetor icing probability chart contained in Federal Aviation Administration Special AirworthinessInformation Bulletin CE-09-35, Carburetor Icing Prevention, the recorded temperature and dew point at the time of the accident were in the range of susceptibility for the formation of serious carburetor icing at glide engine power. According to the bulletin, if ice forms in the carburetor of a fixed-pitch propeller aircraft, the restriction to the induction airflow will result in decreased power output and a drop in engine rpm, which might be accompanied or followed by a rough running engine. The bulletin also notes that a pilot should respond to carburetor icing by applying full carburetor heat immediately and that the engine may run rough initially for a short time while the ice melts. The bulletin further recommends that a pilot use carburetor heat when operating the engine at low power settings or while in weather conditions in which carburetor icing is probable. When interviewed, the pilot acknowledged that he did not review a carburetor icing chart before the flight. However, he stipulated that he applied carburetor heat after the engine began sputtering. ## Aircraft - Registration: [N7878M](https://openairdocs.org/aircraft/N7878M), registered now, S/N 12-3144 (OpenAirDocs) - Reported make and model: PIPER PA-12 - Registry model: [Piper PA-12](https://openairdocs.org/model/piper-pa-12) (registry code 7101202) (OpenAirDocs) - Category: Airplane - Serial number: 12-3144 - Year built: 1947 - Airframe hours: 2563 - Engines: Lycoming O-320-A3B 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Wings Aircraft LLC - Registered owner: Wings Aircraft LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 23, 2024, 6 hours before - Departed: ASX, Ashland, WI - Destination: UBE, Cumberland, WI - Equipment: ADS-B, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 38; injuries: none; private; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review April 13, 2024; seat: front; restraint: 4-point; flight hours: 376 total, 36 in this make and model, 310 as pilot in command, 43 in the last 90 days, 11 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 77 °F, dew point 63 °F - Altimeter: 30.10 inHg - Observed at: KUBE, 5 nm away - METAR: METAR KUBE 121655Z AUTO 10SM CLR 25/17 A3010 RMK AO2= ## 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 20240912014189A](https://openairdocs.org/incident/20240912014189A), Sep 12, 2024: Piper PA-12, Cumberland, MN, Substantial damage. During a cross country flight, the PIC started descending to land. Approximately 5 miles from the airport the engine lost power and the PIC performed an… ## Docket (8 files) The files NTSB released with the investigation on September 18, 2026, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=195116. 6.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20866267&FileExtension=pdf&FileName=01%20-%20Pilot%20Report_Redacted-Rel.pdf - FAA record of conversation with pilot (item 2, PDF, 1 page, 248 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20867220&FileExtension=pdf&FileName=02%20-%20FAA%20Record%20of%20Conversation%20with%20Pilot_Redacted-Rel.pdf - NTSB record of conversation with FAA inspector (item 3, PDF, 3 pages, 99 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20866776&FileExtension=pdf&FileName=03%20-%20NTSB%20Record%20of%20Conversation%20with%20FAA%20Inspector-Rel.pdf - Meteorological data (item 4, PDF, 2 pages, 105 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20867230&FileExtension=pdf&FileName=04%20-%20Meteorological%20Data-Rel.pdf - FAA SAIB CE-09-35 carburetor icing prevention (item 5, PDF, 3 pages, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20867240&FileExtension=pdf&FileName=05%20-%20FAA%20SAIB%20CE-09-35%20Carburetor%20Icing%20Prevention_Redacted-Rel.pdf - Australian civil aviation safety authority article on carburetor icing (item 6, PDF, 2 pages, 227 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20867336&FileExtension=pdf&FileName=06%20-%20Australian%20Civil%20Aviation%20Safety%20Authority%20Article%20on%20Carburetor%20Icing-Rel.pdf - Aopa carburetor icing article (item 7, PDF, 3 pages, 393 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20867250&FileExtension=pdf&FileName=07%20-%20AOPA%20Carburetor%20Icing%20Article_Redacted-Rel.pdf - Photos (item 8, PDF, 5 pages, 4 photos, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=20868060&FileExtension=pdf&FileName=08%20-%20Photos%20(CEN24LA356)-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.