# NTSB CEN21LA133: Aero Commander S2R, N5679X, Alamo, TX, February 9, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: February 9, 2021, 17:30 local (23:30 UTC) - Place: Alamo, TX - Coordinates: 26.153131, -98.135008 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=26.1531&lon=-98.1350&mi=10 - Phase of flight: [Prior to flight](https://openairdocs.org/ntsb-phases/100) (OpenAirDocs' grouping) - Defining event: [Prior to flight: Fuel contamination](https://openairdocs.org/ntsb-events/193) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Flight Standards District Office - NTSB case key (mKey): 102661 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA133 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102661/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102661 - Page: https://openairdocs.org/ntsb/CEN21LA133 ## Probable cause The partial loss of engine power due to water-contaminated fuel. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid condition (probable cause); cases with it: [Aero Commander S2R, 2 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=0143022), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Aero Commander S2R, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=0143022), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Fuel contamination](https://openairdocs.org/ntsb-events/193) (defining event); cases with it: [Aero Commander S2R, 1 case](https://openairdocs.org/ntsb-events/193/sequence.md?model=0143022), [All aircraft, 225 cases](https://openairdocs.org/ntsb-events/193/sequence.md) - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Aero Commander S2R, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=0143022), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Aero Commander S2R, 3 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=0143022), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Aero Commander S2R, 8 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0143022), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot departed for the aerial application flight and noticed an abnormal engine sound as the airplane reached an altitude of about 25 ft above ground level. Concerned that the engine could lose power over obstacles further along the departure leg that included a high traffic highway and a low power line, the pilot elected to make an immediate precautionary landing. During the landing roll, both wings sustained substantial damage due to impact with trees. During postaccident examination of the engine, a small amount of water was observed in the rear carburetor bowl; therefore, it is likely that water-contaminated fuel resulted in a temporary loss of engine power and the abnormal engine sound reported by the pilot. An engine run was conducted with no anomalies noted. ## Factual narrative On February 9, 2021, about 1730 central standard time, an Aero Commander S2R airplane, N5679X, was substantially damaged when it was involved in an accident near Alamo, Texas. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. The pilot departed from Mid-Valley Dusters Inc. Airport (43TX) on the last flight of the day and noticed an abnormal sound from the engine as the airplane reached an altitude of about 25 ft above ground level. He elected to make an immediate precautionary landing rather than risk having the engine lose power over obstacles farther along the departure path that included a high traffic highway and a low power line. During the landing roll, both wings sustained substantial damage due to impact with trees. Examination of engine cylinders, spark plugs, induction tubes, exhaust stacks, and magnetos did not reveal any anomalies that would have precluded normal operation. The fuel tank sumps, header tank sumps, and manual auxiliary fuel pump sumps were drained with no contamination noted. The rear carburetor bowl drain was removed, and a small amount of water-contaminated fuel was observed. The engine was started and accelerated to 1,800 rpm with no anomalies noted. A normal rpm drop occurred when the magnetos were checked, and the propeller cycled normally. No smoke was produced when the engine was returned to idle power, which was consistent with normal functioning of the blower seal. ## Aircraft - Registration: [N5679X](https://openairdocs.org/aircraft/N5679X), registered now, S/N 1879R, built 1974 (OpenAirDocs) - Reported make and model: AERO COMMANDER S2R - Registry model: [Aero Commander S2R](https://openairdocs.org/model/aero-commander-s2r) (registry code 0143022) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1879R - Year built: 1974 - Airframe hours: 14028 - Engines: Pratt & Whitney R1340 AN-1 600 hp reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, August 28, 2020 - Departed: 43TX, Alamo, TX - Airport: 43TX, Mid-Valley Dusters Inc Airport, runway 13, 1,900 × 20 ft, macadam ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 77; injuries: none; commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review February 19, 2020; seat: front; restraint: 4-point; flight hours: 19,845 total, 1,200 in this make and model, 19,600 as pilot in command, 60 in the last 90 days, 25 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 80° at 11 knots - Visibility: 7 statute miles - Lowest ceiling: 4,800 ft broken - Temperature: 79 °F, dew point 66 °F - Altimeter: 30.00 inHg - Observed at: KMFE, 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 20210209001149A](https://openairdocs.org/incident/20210209001149A), Feb 9, 2021: Aero Commander S2R, Alamo, TX, Substantial damage. On February 9, 2021 at 1735 CDT Alamo Texas, N5679X an Aero Commander SR2 thrush operating on a part 137 certificate from (43TX) mid-valley dusters inc.,… ## Docket (4 files) The files NTSB released with the investigation on May 25, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102661. 8.6 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 2.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12179010&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Pilot statement - additional (item 2, PDF, 1 page, 3.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12186063&FileExtension=pdf&FileName=Pilot%20Statement%20-%20Additonal-Rel.pdf - Aircraft examination (item 3, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12179267&FileExtension=pdf&FileName=Exam-Rel.pdf - Photos of airplane (item 4, PDF, 2 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12179181&FileExtension=pdf&FileName=Photos-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.