# NTSB CEN11LA089: Cessna 180, N3246D, Omaha, NE, December 2, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: December 2, 2010, 04:30 local (10:30 UTC) - Place: Omaha, NE - Coordinates: 41.302776, -95.89389 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.3028&lon=-95.8939&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 26, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 77922 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11LA089 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77922/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77922 - Page: https://openairdocs.org/ntsb/CEN11LA089 ## Probable cause A loss of engine power due to a stuck check valve in the carburetor acceleration pump, resulting in an improper fuel mixture when the pilot attempted to add power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuel system: fuel distribution](https://openairdocs.org/ntsb-findings/01022820): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Cessna 180, 1 case](https://openairdocs.org/ntsb-findings/01022820/cases.md?model=2072602), [All aircraft, 141 cases](https://openairdocs.org/ntsb-findings/01022820/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: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Cessna 180, 8 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2072602), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) ## Analysis During the landing approach and 1/2-mile from the runway, the engine lost power. During the ensuing forced landing, the airplane impacted a tree and terrain. During postaccident functional testing of the engine, it lost power when the throttle was moved quickly from a low power setting to a high power setting, and became more pronounced as the engine got warmer. The carburetor was removed from the engine and a visual inspection was conducted. A roughness was felt in the accelerator pump while manually moving the control at the carburetor, and very little fuel flow came from the accelerator pump. The carburetor was disassembled and all check valves, ports and vents, the venturi, nozzle bleed holes, carburetor bowl vent channels, and float assembly were cleaned. After reassembly, a much higher fuel output was achieved. The carburetor and accelerator pump were reinstalled on the engine, and all functional checks were normal. ## Factual narrative On December 2, 2010, approximately 0430 central standard time, a Cessna 180, N3246D, registered to and operated by the pilot, was substantially damaged when the pilot made a forced landing and impacted terrain after the engine lost power on landing approach to Eppley Airfield (OMA), Omaha, Nebraska. Visual meteorological conditions (VMC) prevailed at the time of the accident. The personal flight was being conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. The pilot, the sole occupant on board. was not injured. The cross-country flight originated in Butte, Montana, with a refueling stop in Philip (PHP), South Dakota, and was ultimately destined for London (LOZ), Kentucky. According to Federal Aviation Administration (FAA) inspectors, the pilot was on landing approach and 1/2-mile from runway 14L when the engine lost power. During the ensuing forced landing, the airplane impacted a small tree and terrain, and came to rest with the nose facing south and the left wing tip in the water. The right wing was compressed, and the horizontal stabilizer was torn off. The engine cowling, both elevators, both ailerons, and both wing tips were damaged. Fuel was seen leaking from the compromised fuel tanks. The airplane was removed to a nearby airport hangar. It was examined on December 3 and 7, 2010. During the examinations, both wing fuel sumps, the engine fuel sump, fuel bowl and carburetor fuel and inlet screens were found clear of contamination. Both magnetos were turned and all spark plugs fired. There were no leaks in the intake system, and all cylinders had satisfactory compression. Valve train continuity was established. On December 9, a bench propeller was installed. During functional testing, the engine lost power when the throttle was quickly moved from a low power setting to a high power setting, and became more pronounced as the engine got warmer. A roughness was felt in the accelerator pump while manually moving the control at the carburetor. Very little fuel flow came from accelerator pump. The carburetor (model number MA-4-5, serial number 3986073-R MF-V) was removed, disassembled, and all check valves, ports and vents, the venturi, nozzle bleed holes, carburetor bowl vent channels, and float assembly were cleaned. After reassembly, a much higher fuel output was achieved. The carburetor and accelerator pump were reinstalled on the engine. All functional checks were normal. The inspectors concluded that the carburetor acceleration pump or the check valve below it had become stuck, resulting in an improper fuel mixture when the pilot attempted to add power, causing the engine to lose power. ## Aircraft - Registration: [N3246D](https://openairdocs.org/aircraft/N3246D), registered now, S/N 32044, built 1955 (OpenAirDocs) - Reported make and model: CESSNA 180 - Registry model: [Cessna 180](https://openairdocs.org/model/cessna-180) (registry code 2072602) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 32044 - Engines: Continental O-470-A 225 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Stephen Walters - Registered owner: Stephen Walters - Airworthiness certificate: Standard, Normal - Departed: PHP, Philip, SD - Destination: OMA, Omaha, NE - Airport: OMA, Eppley Airfield, runway 14L, 7,020 × 150 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; seat: left ## Weather - Conditions: Visual (VMC), Night - Observed at: OMA, 2 nm away ## 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 20101202052419A](https://openairdocs.org/incident/20101202052419A), Dec 2, 2010: Cessna 180, Omaha, NE, Substantial damage. On Thursday, December 2, 2010, at approximately 0430 CST, Cessna 180, N3246D, owned and operated by stephen p. walters, landed approximately 1/2 mile short of… ## Docket (4 files) The files NTSB released with the investigation on March 16, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77922. 2.4 MB in all. - NTSB Form 6120, Pilot-Operator Aircraft Accident Report (item 1, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345090&FileExtension=.PDF&FileName=NTSB%20Form%206120,%20Pilot-Operator%20Aircraft%20Accident%20Report-Redacted.PDF - Report of Events (from the pilot's perspective) (item 2, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40342870&FileExtension=.PDF&FileName=Report%20of%20Events%20(from%20the%20pilot%27s%20perspective)-Master.PDF - FAA Inspector's Memorandum (item 3, .PDF, 22 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40342850&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Memorandum-Redacted.PDF - Weather Reports and Records (item 4, .PDF, 40 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40342853&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.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.