# NTSB CEN21LA473: Beech 35-A33, N5ML, Mineral Wells, TX, July 23, 2021 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: July 23, 2021, 07:45 local (12:45 UTC) - Place: Mineral Wells, TX - Coordinates: 32.7894, -98.0691 - Nearby events: https://openairdocs.org/map.md?lat=32.7894&lon=-98.0691&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 104113 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA473 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104113/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104113 - Page: https://openairdocs.org/ntsb/CEN21LA473 ## Probable cause A partial loss of engine power for reasons that could not be determined based on available evidence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Unknown/Not determined (probable cause); cases with it: [Beech 35-A33, 2 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=1151404), [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. - [Approach-VFR pattern final: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) (defining event); cases with it: [Beech 35-A33, 2 cases](https://openairdocs.org/ntsb-events/000/sequence.md?model=1151404), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) - [Approach-VFR pattern final: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Beech 35-A33, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=1151404), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) ## Analysis After a normal takeoff, the pilot encountered low clouds en route to his destination. He diverted to a nearby airport and avoided the clouds as he descended toward the airport. He entered a downwind for the runway and reduced the engine to a low power setting. After turning final, the pilot attempted to add power; however, the engine did not respond. He manipulated the throttle several times, but the engine did not increase from idle power. The pilot initiated a landing to a nearby field. The airplane touched down hard, the nose gear collapsed, and the airplane came to rest. During an on-scene examination, the fuel selector was found positioned on the left tank. About 3 inches of fuel was observed in the right-wing fuel tank, and no visible fuel was noted in the left-wing fuel tank. During a discussion with the pilot, he reported that the airplane was on the right fuel tank when the loss of power occurred. After recovery, a temporary fuel tank was connected to the fuel line at the left-wing root to facilitate an engine run. The airplane started and operated uneventfully at various engine speeds with no anomalies noted. Since the engine operated normally postaccident, and fuel was present in the right fuel tank, it is likely the engine was starved of fuel during the accident flight, which resulted in a loss of engine power. ## Factual narrative On July 23, 2021, at 0745 central daylight time, a Beech 35-A33 airplane, N5ML, was substantially damaged when it was involved in an accident near Mineral Wells Regional Airport (MWL), Mineral Wells, Texas. The pilot and passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot and passenger reported that the purpose of the flight was to fill the airplane with fuel for an upcoming flight. After a normal takeoff, they encountered low, dense clouds. The pilot elected to divert to MWL, and he conducted a spiral descent through a hole in the clouds. When the airplane entered downwind for runway 13, he reduced the engine to a low power setting. After turning final, the pilot attempted to add power; however, the engine did not respond. He confirmed the engine was still operating by looking at the manifold and fuel pressure gauges. He then manipulated the throttle several times, but the engine did not increase from idle. The pilot initiated a landing to a nearby field. The airplane touched down hard, the nose gear collapsed, and the airplane came to rest. On-scene examination by a Federal Aviation Administration (FAA) inspector noted that the right wing was wrinkled; however, there were no visible indications of a fuel leak. The auxiliary fuel tank gauge indicated empty, and the main fuel tank gauge indicated ¼ tank full when power was applied to the airplane. The right-wing fuel tank contained about 3 inches of fuel, and no visible fuel was noted in the left-wing fuel tank. The fuel selector was found selected to the left tank; however, during a discussion with the pilot, he reported that the right fuel tank was selected when the loss of power occurred. He reported that he turned off the fuel after the accident but must have accidentally placed the fuel selector on the left fuel tank. After the airplane was recovered, the propeller was replaced, and a temporary fuel tank was connected to the fuel line at the left-wing root to facilitate an engine run. The airplane started uneventfully and idled for a short time. The throttle was advanced to various rpm settings, and the engine responded accordingly. The propeller control was manipulated, and a magneto check was completed with no anomalies noted. ## Aircraft - Registration: [N5ML](https://openairdocs.org/deregistered/N5ML-2023-09-16), registration cancelled 2023-09-16, S/N CD-225 (OpenAirDocs) - Reported make and model: BEECH 35-A33 - Registry model: [Beech 35-A33](https://openairdocs.org/model/beech-35-a33) (registry code 1151404) (OpenAirDocs) - Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: CD-225 - Year built: 1060 - Engines: Continental Motors IO-520-BB 285 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: The Red Team LLC - Airworthiness certificate: Standard, Normal - Departed: XS53, Weatherford, TX - Destination: Same as departure - Airport: MWL, Mineral Wells Regional Airport, runway 13, 5,996 × 100 ft, asphalt - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; seat: left; restraint: lap only; flight hours: 782 total, 1 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: 1,900 ft broken - Temperature: 73 °F, dew point 70 °F - Altimeter: 30.11 inHg - Observed at: KMWL, 1 nm away - METAR: KMWL 231253Z AUTO 14007KT 10SM BKN019 OVC024 23/21 A3011 RMK AO2 SLP182 T02330211 ## 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 20210723011939A](https://openairdocs.org/incident/20210723011939A), Jul 23, 2021: Beech 35-A33, Mineral Wells, TX, Substantial damage. Pilot and 1 passenger took off from private strip, XS53, near peaster, TX enroute to bridgeport (kxbp) to fill aircraft with gas. They encountered low clouds… ## Docket (6 files) The files NTSB released with the investigation on September 1, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104113. 21.2 MB in all. - Pilot statement - provided to the federal aviation administration (item 1, PDF, 2 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13816778&FileExtension=pdf&FileName=Statement%20of%20Earl%20Fields%20pilot-Rel.pdf - Passenger statement - provided to the federal aviation administration (item 2, PDF, 1 page, 918 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13805008&FileExtension=pdf&FileName=Statement%20of%20William%20Elms%20passenger_Redacted-Rel.pdf - Record of memorandum, FAA on scene (item 3, PDF, 3 pages, 765 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14390888&FileExtension=pdf&FileName=ROM%20FAA%20ON%20SCENE-Rel.pdf - Engine run summary (item 4, PDF, 3 pages, 869 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13805726&FileExtension=pdf&FileName=Examination%20Summary%20with%20508-Rel.pdf - Video - a portion of the engine run (item 5, MP4, 17.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13804537&FileExtension=MP4&FileName=MVI_3357-Rel.MP4 - Release of aircraft wreckage, NTSB form 6120.15 (item 6, PDF, 1 page, 248 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13450365&FileExtension=pdf&FileName=Wreckage%20Release%20N5ML%20signed%20printed_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.