# NTSB CEN20LA360: Cessna 180, N7620A, St Louis, MO, August 22, 2020 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: August 22, 2020, 11:51 local (16:51 UTC) - Place: St Louis, MO - Coordinates: 38.623332, -90.542778 - Nearby events: https://openairdocs.org/map.md?lat=38.6233&lon=-90.5428&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Textron Aviation, Flight Standards District Office, Continental Motors - NTSB case key (mKey): 101851 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20LA360 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101851/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101851 - Page: https://openairdocs.org/ntsb/CEN20LA360 ## Probable cause A total loss of engine power due to improper maintenance of the mixture control cable and attachment hardware, which led to a forced landing into a congested area. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Cessna 180, 1 case](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=2072602), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md) - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Cessna 180, 1 case](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=2072602), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md) - [Maintenance](https://openairdocs.org/ntsb-findings/02062000): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Cessna 180, 2 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md?model=2072602), [All aircraft, 143 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna 180, 9 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2072602), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Cessna 180, 2 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=2072602), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis While in cruise flight, the pilot reported hearing a loud “pop,” and the engine suddenly lost power. The pilot executed a forced landing toward a lacrosse field surrounded by residences. The airplane impacted terrain in a nose-down attitude, which substantially damaged both wings and seriously injured the pilot. A postaccident examination revealed that the carburetor mixture control cable was disconnected from the carburetor control lever at the carburetor, with the attachment hardware (bolt, nut, and washer stack) still attached to the carburetor. No other anomalies were found that would have precluded normal operation. Laboratory analysis of the mixture control cable and attachment hardware (bolt, nut, and washer stack) determined that the hardware was used repeatedly in numerous configurations, and the cable did not have a kink at the end indicating it had not been bent. The maintenance manual specified that the cable was to be bent 90 degrees after being threaded through the bolt hole to help secure the cable, and not doing so likely contributed to the cable becoming disconnected from the carburetor control lever inflight. ## Factual narrative On August 22, 2020, about 1151 central daylight time, a Cessna 180 airplane, N7620A, was substantially damaged when it was involved in an accident near St. Louis, Missouri. The pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that while en route about 5 minutes after takeoff, he heard a loud "pop" followed by a sudden loss of engine power. The pilot executed a forced landing toward a lacrosse field surrounded by residences. The airplane subsequently impacted terrain short of the field in a nose-low attitude, which resulted in damage to both wings and fuselage. Postaccident examination of the flight controls, fuel system, and muffler revealed no anomalies. Fuel collected from the gascolator was observed to have normal color and smell, with no signs of visual contamination. The engine crankshaft was rotated, and all cylinders showed evidence of compression. No anomalies were noticed with the magnetos or spark plugs. The carburetor mixture control cable was found disconnected from the control lever at the carburetor, with the attachment hardware (bolt, nut, and washer stack) still attached to the carburetor. The carburetor mixture control lever, which was not spring loaded toward a particular direction, was found at the cut-off position. The cockpit mixture control lever was about 2 inches from the full rich position. The carburetor was examined at a repair facility. No anomalies were observed that would have led to a fuel stoppage of the engine. A section of the carburetor mixture cable and attachment hardware were examined at the National Transportation Safety Board (NTSB) Materials Laboratory. The central wire of the mixture control cable had multiple flat areas around the outer diameter. The attachment hardware bolt had bands of wear on the outer diameter consistent with rub damage from the washers, and the washer faces had circumferential wear marks consistent with rub damage. The engine maintenance manual specified that the carburetor mixture control wire was to be bent 90º after being threaded through the bolt hole to help secure the wire. No evidence of a kink or sharp bend was observed at the wire end. ## Aircraft - Registration: [N7620A](https://openairdocs.org/deregistered/N7620A-2021-11-06), registration cancelled 2021-11-06, S/N 32517, built 1956 (OpenAirDocs) - Reported make and model: Cessna 180 (UNDESIGNAT) - Registry model: [Cessna 180](https://openairdocs.org/model/cessna-180) (registry code 2072602) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: 32517 - Year built: 1956 - Airframe hours: 4446 - Engines: Continental O-470-K 230 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Casement Llc - Registered owner: Casement Llc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 1, 2020, 10 hours before - Departed: 1H0, St Louis, MO - Destination: H88, Fredericktown, MO - Equipment: ADS-B, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: serious; private; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review April 18, 2020; seat: left; flight hours: 1,200 total, 105 in this make and model, 14 in the last 90 days, 3 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Temperature: 84 °F, dew point 64 °F - Altimeter: 29.96 inHg - Observed at: KSUS, 6 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 20200822017349A](https://openairdocs.org/incident/20200822017349A), Aug 22, 2020: Cessna 180, Chesterfield, MO, Substantial damage. An aircraft accident occurred on August 22, 2020 at approximately 11:52 involving a Cessna (Textron) CE-180 s/n 3517 registration number N7620A. The aircraft… ## Docket (11 files) The files NTSB released with the investigation on May 12, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101851. 34.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 7 pages, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13572817&FileExtension=pdf&FileName=6120%20-%20CEN20LA360%20-%20St%20Louis,%20MO%20-%20C180_Redacted-Rel.pdf - Police report excerpt - witness statements (item 2, PDF, 2 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13573685&FileExtension=pdf&FileName=Excerpt%20of%20Police%20Report_Redacted-Rel.pdf - FAA inspector statement (item 3, PDF, 1 page, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13573433&FileExtension=pdf&FileName=FAA%20Inspector%20Statement-Rel.pdf - Powerplant maintenance manual - excerpt (item 4, PDF, 1 page, 4.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13582826&FileExtension=pdf&FileName=Powerplant%20Maintenance%20Manual%20-%20Excerpt-Rel.pdf - Maintenance records - excerpt (item 5, PDF, 19 pages, 15.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13671404&FileExtension=pdf&FileName=Logbook%20entries%20-%20last%202%20yrs_Redacted-Rel.pdf - Photos of airplane at accident site (item 6, PDF, 3 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13580968&FileExtension=pdf&FileName=Photos-Rel.pdf - Overhead view of accident site (item 7, PDF, 1 page, 209 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13671089&FileExtension=pdf&FileName=Overhead%20View%20of%20Accident%20Location-Rel.pdf - Carburetor exam (item 8, PDF, 1 page, 458 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13572880&FileExtension=pdf&FileName=Carb%20exam%20-%20Cessna%20180%20-%20CEN20LA360-Rel.pdf - NTSB materials lab - factual report (item 9, PDF, 12 pages, 6.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13573332&FileExtension=pdf&FileName=NTSB%20Materials%20Lab%20Factual%20Report-Rel.pdf - Statement of party representatives to NTSB investigation (item 10, PDF, 2 pages, 319 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13573734&FileExtension=pdf&FileName=Party%20Member%20Forms_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 11, PDF, 1 page, 171 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13708107&FileExtension=pdf&FileName=Wreckage%20Release_Redacted-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.