# NTSB CEN20LA420: Beech V35, N3958A, Terrell, TX, September 24, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: September 24, 2020, 13:50 local (18:50 UTC) - Place: Terrell, TX · 75160 - Coordinates: 32.787931, -96.093123 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.7879&lon=-96.0931&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Fuel starvation](https://openairdocs.org/ntsb-events/191) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Continental Engines, Federal Aviation Administration, Textron Aviation - NTSB case key (mKey): 102043 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20LA420 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102043/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102043 - Page: https://openairdocs.org/ntsb/CEN20LA420 ## Probable cause Fuel starvation due to a fuel system leak, which resulted in a loss of engine power and the subsequent forced landing on unsuitable terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuel system: fuel filter-strainer](https://openairdocs.org/ntsb-findings/01022821): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Beech V35B, 1 case](https://openairdocs.org/ntsb-findings/01022821/cases.md?model=1151548), [All aircraft, 52 cases](https://openairdocs.org/ntsb-findings/01022821/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Beech V35B, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=1151548), [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. - [Enroute: Fuel starvation](https://openairdocs.org/ntsb-events/191) (defining event); cases with it: [Beech V35B, 3 cases](https://openairdocs.org/ntsb-events/191/sequence.md?model=1151548), [All aircraft, 733 cases](https://openairdocs.org/ntsb-events/191/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Beech V35B, 8 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=1151548), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Beech V35B, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=1151548), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported that he performed a preflight inspection of the airplane that included “physical fuel level inspection in each wing with [a] flashlight.” He checked both wing fuel sumps and drained the fuel sump twice on the left side. Additionally, he sampled the fuel in the belly fuel sump and then secured its door. About 30 minutes after departure, when the airplane was about 2,200 ft mean sea level, the engine lost power. The pilot switched the selector from the left fuel tank to the right fuel tank. However, the engine did not respond, and he performed a forced landing, during which the airplane impacted trees and terrain, resulting in substantial damage to both wings, the fuselage, and the empennage. An initial on-site examination of the airplane revealed the right wing contained fuel and the left wing was compromised from impact damage. Further examination revealed the engine sustained damage and could not be test run. However, no preimpact engine anomalies were detected that would affect normal engine operation. The fuselage fuel gascolator was removed. Its fuel screen was clear of debris or contaminants. However, a blue stain consistent with the color of 100 low-lead aviation gasoline was observed both on the exterior of the bowl and top of the unit. Given the stain on the outside of the gascolator, it is likely that a leak in at the gascolator allowed air to enter and fuel starvation to occur, which resulted in the loss of engine power and subsequent forced landing. ## Factual narrative On September 24, 2020, about 1350 central daylight time, a Beech V35 B airplane, N3958A, sustained substantial damage when it was involved in an accident near Terrell, Texas. The pilot was uninjured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot, who had recently purchased the airplane, reported that he performed a preflight inspection of the airplane that included “physical fuel level inspection in each wing with [a] flashlight.” He checked both wing fuel sumps and drained the fuel sump twice on the left side. Additionally, he sampled the fuel in the belly fuel sump and then secured its door. The flight departed Propwash Airport, Justin, Texas, about 1320, and was destined for Van Zandt County Regional Airport, Wills Point, Texas. The pilot reported that about 30 minutes after departure, when the airplane was about 2,200 ft mean sea level, the engine lost power. He switched the selector from the left fuel tank to the right fuel tank. However, the engine did not respond, and he performed a forced landing, during which the airplane impacted trees and terrain; the airplane sustained substantial damage to both wings, the fuselage, and the empennage. An examination of the airplane at the accident site found that the right wing contained fuel and that the left wing was compromised from impact damage. The pilot said that the fuel gauges indicated half tanks for both wings. The airplane wreckage was recovered for further examination. The engine mount area was damaged, and the engine had impacted the firewall area. An engine test run was not able to be performed. The three-bladed propeller remained attached to the engine crankshaft flange, the tip of one blade was bent aft, and another blade had a slight bend aft about mid-span. The throttle and mixture controls cables were attached to their respective controls. The fuel manifold’s fuel lines were connected. The engine-driven fuel pump was removed; the pump turned freely, and its drive shear shaft was intact. The top set of spark plugs was removed; normal wear on the electrodes was noted. The engine timing was checked and appeared to be 22°, which was consistent with the factory setting. Thumb compression and suction were noted on each cylinder when the engine was rotated using the propeller. Additionally, each magneto impulse coupling was heard during engine rotation. Spark was observed on each of the top set of ignition leads. Continuity through the valve train and accessory drive was confirmed. The oil filter remained attached to its mount and was removed. The filter contained a small amount of engine oil. No contaminants or debris was observed in the oil. The inlet fuel screen for the fuel servo was removed and was clear of debris. The fuselage fuel gascolator (located on the left side of the fuselage) was removed. Its fuel screen was clear of debris or contaminants. However, a blue stain, which was consistent with the color of 100 low-leadaviation gasoline, was observed both on the exterior of the bowl and top of the unit. The airplane was modified with wing tip fuel tanks that were subsequently removed. However, the airplane components were not placarded that the wing tip tanks were removed. There were no other preimpact anomalies noted during the examination that would have affected normal engine operation ## Aircraft - Registration: [N3958A](https://openairdocs.org/aircraft/N3958A), registered now, S/N D-9194, built 1970 (OpenAirDocs) - Reported make and model: BEECH V35 (B) - Registry model: [Beech V35B](https://openairdocs.org/model/beech-v35b) (registry code 1151548) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: D-9194 - Year built: 1970 - Engines: Continental IO-550-B4F 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 10, 2020 - Departed: 16X, Justin, TX - Destination: 76F, Wills Point, TX - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: basicmed; seat: left; restraint: 3-point; flight hours: 1,500 total, 313 in this make and model, 1,259 as pilot in command, 13 in the last 90 days, 8 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 1,700 ft overcast - Temperature: 66 °F, dew point 61 °F - Altimeter: 30.00 inHg - Observed at: KTRL, 10 nm away - METAR: KTRL 241753Z AUTO 35006KT 10SM OVC017 19/16 A3000 RMK AO2 SLP153 60000 T01940156 10194 20172 57004 ## 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 20200924018559A](https://openairdocs.org/incident/20200924018559A), Sep 24, 2020: Beech V35B, Terrell, TX, Substantial damage. On September 24, 2020 at approximately 14:00 CDT, aircraft N3958A, a Beechcraft V35B, experienced a loss of power while enroute from propwash airport (16X)… ## Other investigations on N3958A (1) 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. - [NTSB DEN71AD017](https://openairdocs.org/ntsb/DEN71AD017), Oct 17, 1970: Beech V35B (N3958A), Aspen, CO, destroyed, 2 fatal ## Docket (8 files) The files NTSB released with the investigation on March 3, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102043. 23.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11599867&FileExtension=pdf&FileName=6120_%20Redacted-Rel.pdf - Pilot's statement (item 2, PDF, 2 pages, 14.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11599413&FileExtension=pdf&FileName=N3958A%20Narrative%20Oct%205%202020_Redacted-Rel.pdf - Miscellaneous information - xbp fuel receipt -- 100LL 9/16/2020 --- 59.110 gallons (item 3, PDF, 1 page, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11415028&FileExtension=pdf&FileName=20Fuel%20Reciept420%20_Redacted-Rel.pdf - Photos (item 4, PDF, 15 pages, 15 photos, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11599807&FileExtension=pdf&FileName=20photo420-Rel.pdf - FAA inspector's statement - wreckage examination summary -- c anthony (item 5, PDF, 1 page, 65 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11599877&FileExtension=pdf&FileName=20Wreckage%20Exam%20Summary420-Rel.pdf - Powerplants - engine/airplane examination - c hatch (item 6, PDF, 2 pages, 26 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11599319&FileExtension=pdf&FileName=Examination%20Summary%20-%20V35B%20%20CEN20LA420%20N3958A-Rel.pdf - Maintenance records - mechanic's statement (item 7, PDF, 12 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11599948&FileExtension=pdf&FileName=AnnualWorkOrder%20N3958A_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 8, PDF, 1 page, 441 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11626227&FileExtension=pdf&FileName=NTSB%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.