# NTSB CEN24LA065: Beech B36TC, N70SL, Burnet, TX, December 17, 2023 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: December 17, 2023, 14:14 local (20:14 UTC) - Place: Burnet, TX - Coordinates: 30.738927, -98.23861 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.7389&lon=-98.2386&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Continental Aerospace Technologies, Textron Aviation, American Bonanza Society, Federal Aviation Administration, San Antonio FSDO - NTSB case key (mKey): 193534 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN24LA065 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193534/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=193534 - Page: https://openairdocs.org/ntsb/CEN24LA065 ## Probable cause The loss of engine power due an overly rich mixture from an improper adjustment of the fuel pump, which resulted in a forced landing and impact with a car and terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuel system](https://openairdocs.org/ntsb-findings/01022800): Aircraft › Aircraft systems · Not specified (probable cause); cases with it: [Beech B36TC, 1 case](https://openairdocs.org/ntsb-findings/01022800/cases.md?model=1151609), [All aircraft, 181 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md) - [Fuel system: fuel pumps](https://openairdocs.org/ntsb-findings/01022822): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Beech B36TC, 2 cases](https://openairdocs.org/ntsb-findings/01022822/cases.md?model=1151609), [All aircraft, 71 cases](https://openairdocs.org/ntsb-findings/01022822/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Beech B36TC, 3 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=1151609), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Initial climb: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Beech B36TC, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=1151609), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Beech B36TC, 8 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=1151609), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Beech B36TC, 7 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1151609), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Beech B36TC, 7 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1151609), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot stated the preflight, engine start, engine runup, and takeoff roll were normal. While climbing through 200 to 300 ft above ground level (agl) after takeoff, the engine began to surge and lose power. Black smoke was seen coming from the airplane’s exhaust during the takeoff and climb. The airplane was unable to climb, and the pilot was unsuccessful using emergency procedures at regaining engine power. The pilot said that the only area suitable for landing that he saw was a road. During the landing, the airplane’s right wing struck a car, and the airplane exploded into flames. The airplane came to rest in a field and was destroyed by impact forces and postcrash fire. Postaccident examination and testing of the engine-driven fuel pump revealed that it was adjusted for a fuel flow that exceeded the maximum limitation for the pump. Symptoms of a rich mixture to include black exhaust smoke and sluggish engine operation, were witnessed during the airplane’s takeoff and climb. ## Factual narrative On December 17, 2023, about 1414 central standard time, a Beech B36TC, N70SL, was destroyed when it was involved in an accident near Burnet, Texas. The pilot and passenger received serious injuries. The airplane was operated under Title 14 Code of Federal Regulations as a Part 91 personal flight. The pilot stated the preflight, engine start, engine runup, and takeoff roll were normal. While climbing through 200 to 300 ft agl, the engine began to surge and lose power. The airplane was unable to climb, and the pilot was unsuccessful using emergency procedures at regaining engine power. The pilot said he could not see an area suitable to land on except for a road. During the landing, the airplane’s right wing struck a car and exploded into flames. The airplane landed in a field and was destroyed by impact forces and postcrash fire. A witness stated that he saw the airplane intermittently emitting black smoke from the exhaust as it climbed out slowly after takeoff. A video of the takeoff showed dark smoke emitting from the airplane’s exhaust area. A second witness saw the airplane fly southbound at an estimated altitude of 100 to 150 ft agl and was having difficulty gaining altitude. The airplane’s landing gear was retracted, the wing flaps were retracted, and the propeller was turning. The airplane lost altitude and descended behind a hill. The engine-driven fuel pump assembly was removed for testing at Continental Aerospace Technologies, Mobile, Alabama, under the supervision of the NTSB Investigator-in-Charge. The fuel pump assembly was placed on a test bench and during testing at an input speed of 2,700 rpm, the fuel flow was 38.42 gallons per hour and the maximum limit for the test was 34.9 gallons per hour. There was no test fluid leakage from the fuel pump assembly during the test. The fuel pump assembly was removed from the test bench and disassembled to determine the length of its internal aneroid. The fuel pump assembly’s aneroid adjustment screw was extended outward 0.4480 inch. The internal aneroid was not elongated and was of comparable length to the aneroid of a new production fuel pump assembly, which indicated a normal condition. According to Continental Aerospace Technologies, the greater the outward extension of the aneroid adjustment screw, the greater the output of fuel flow from the fuel pump assembly. A review of the engine maintenance logbooks showed that the fuel pump was overhauled in June 2004, and that the engine was overhauled April 14, 2022. There were no other references to work or adjustments done on the fuel pump. The Federal Aviation Administration Aviation Maintenance Technician Handbook–Powerplant (2023), Chapter 10, Engine Maintenance & Operation, Engine Troubleshooting, Figure 10-52, lists symptoms of a rich mixture to include black exhaust smoke and sluggish engine operation. ## Aircraft - Registration: [N70SL](https://openairdocs.org/aircraft/N70SL), registered now, S/N EA-459, built 1986 (OpenAirDocs) - Reported make and model: BEECH B36TC - Registry model: [Beech B36TC](https://openairdocs.org/model/beech-b36tc) (registry code 1151609) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: EA-459 - Year built: 1986 - Engines: Continental TSIO520-UB 300 horsepower reciprocating - Damage: Destroyed - Fire: Both - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Destination: CXO, Conroe, TX - Airport: BMQ, Burnet Municipal Airport/Kate Craddock Field, runway 19, 5,001 × 75 ft, asphalt - Equipment: Stall warning system, ADS-B, Electronic flight bag or handheld device, Auto-pilot, Onboard weather, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: serious; airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1; seat: left; restraint: 3-point; flight hours: 15,600 total, 11,000 as pilot in command, 230 in the last 90 days, 85 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 32 °F - Altimeter: 30.05 inHg - Observed at: BMQ, 0.5 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 20231217021569A](https://openairdocs.org/incident/20231217021569A), Dec 17, 2023: Beech B36TC, Burnet, TX, Destroyed. On December 17, 2023, at approximately 1400 CDT, aircraft [privacy data omitted] lost engine power during takeoff from Burnet municipal airport (kbmq), runway… ## Docket (7 files) The files NTSB released with the investigation on April 1, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=193534. 67.5 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18301616&FileExtension=pdf&FileName=6120%20Master_Redacted-Rel.pdf - Witness statements (item 2, PDF, 2 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18304176&FileExtension=pdf&FileName=Witness%20Master_Redacted-Rel.pdf - Video of accident takeoff (item 3, MOV, 47.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18300888&FileExtension=MOV&FileName=N70SL%20Takeoff%20Video-Rel.MOV - Maintenance records (item 4, PDF, 32 pages, 13.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18434308&FileExtension=pdf&FileName=Aircraft%20Records%20Master_Redacted-Rel.pdf - Photos (item 5, PDF, 5 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18433459&FileExtension=pdf&FileName=Photo%20Template-Rel.pdf - Statement of party representatives to NTSB investigation (item 6, PDF, 3 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18303665&FileExtension=pdf&FileName=Party%20Master_Redacted-Rel.pdf - Memorandum for record a�� NTSB factual review Continental aerospace technologies (item 7, PDF, 1 page, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18425542&FileExtension=pdf&FileName=MOR%20Template%20Continental%20Report%20Review-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.