# NTSB ERA21LA112: Cessna U206, Denton, NC, January 23, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: January 23, 2021, 14:55 local (19:55 UTC) - Place: Denton, NC - Coordinates: 35.705403, -80.048596 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.7054&lon=-80.0486&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: Textron Aviation, FAA - NTSB case key (mKey): 102554 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA21LA112 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102554/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102554 - Page: https://openairdocs.org/ntsb/ERA21LA112 ## Probable cause A partial loss of engine power for reasons that could not be determined based on available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined; cases with it: [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing-landing roll: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis About 2 hours into the aerial observation flight at 250 ft above ground level, the engine lost partial power. The pilot maneuvered for a forced landing, during which, the airplane bounced, and the nose gear fractured and bent under the fuselage, resulting in substantial damage. Postaccident examination of the engine and fuel system and a test run of the engine revealed no anomalies. The reason for the partial loss of engine power could not be determined based on the available information. ## Factual narrative On January 23, 2021, about 1455 eastern standard time, a Cessna U206G, Canadian registration C-GWAS, was substantially damaged when it was involved in an accident in Denton, North Carolina. The pilot and copilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 aerial observation flight. According to the pilot, she and the copilot had been flying mapping flights for the United States Geological Survey. The pilot stated they would fly about 250 ft above ground level in a grid pattern while mapping. She further stated that they had enough fuel on board for an approximate 6-hour flight. They departed Montgomery County Airport (43A), Star, North Carolina, about 1300 and planned on returning to the same airport. About 2 hours into the flight, the engine “rolled back” and started to lose power. The airplane immediately began to lose altitude and the pilot maneuvered the airplane for a forced landing. During landing, the airplane bounced, and the nose landing gear fractured and bent under the fuselage. The airplane slid into trees and both pilots egressed through the door. Postaccident examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that the firewall was creased, and the aft right engine mount structure was cracked. Further examination of the airplane revealed that the airplane was modified in accordance with a Supplemental Type Certificate (STC), which permitted the installation of additional fuel tanks in the wings outboard of the main fuel tanks. The additional tanks were connected directly to the main tanks by fuel and vent lines, for a total fuel capacity of 127 gallons. Internal examination of all fuel tanks revealed no anomalies. Fuel line continuity and selector valve operation was checked by blowing compressed air through the lines. All three propeller blades were bent aft mid-blade. The top spark plugs were removed and showed normal wear. The propeller was rotated by hand and thumb compression was established on all cylinders. The magneto impulse couplings could be heard engaging during rotation. The spark plugs were reinstalled, and a portable fuel can was connected to the upper left wing fuel line for preparation of a test run of the engine. The airplane fuel system was used from the wing attachment point to the engine, however; when the nose gear separated during the impact sequence, both fuel lines were separated from the fuel strainer. The strainer was removed, and the fuel lines were connected with a plastic hose for the engine run. The fuel strainer screen was clear of debris. The fuel selector was placed on the left fuel tank position, the boost pump was turned on until fuel pressure was established, and the starter was engaged. After two revolutions of the propeller, the engine started and ran nominally. The throttle was advanced to different power setting and the engine responded accordingly. No anomalies were noted with the engine and fuel system. ## Aircraft - Registration: C-GWAS (not matched to a registry record) - Reported make and model: CESSNA U206 (G) - Category: Airplane - Serial number: U20603581 - Year built: 1977 - Airframe hours: 9002.5 - Engines: Continental IO-520F 300 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Non-U.S., commercial - Operator: Questor Aviation LTD. - Registered owner: Questor Aviation LTD. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 15, 2021 - Departed: 43A, Star, NC - Flight plan: Company VFR - Equipment: ADS-B, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; injuries: none; private, commercial; airplane ratings: single-engine land, multi-engine land, single-engine sea, multi-engine sea; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review October 12, 2020; seat: left; restraint: 3-point; flight hours: 985 total, 200 in this make and model, 860 as pilot in command, 204 in the last 90 days, 34 in the last 30 days, 4 in the last 24 hours - Co-pilot; age 29; injuries: none; private, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review October 9, 2020; seat: right; restraint: 3-point; flight hours: 6,100 as pilot in command, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 46 °F, dew point 5 °F - Altimeter: 30.21 inHg - Observed at: KHBI, 8 nm away - METAR: KHBI 231955Z AUTO 02007KT 10SM CLR 08/M15 A3021 RMK AO2 T00811148 ## Docket (10 files) The files NTSB released with the investigation on December 8, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102554. 7.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12138592&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Record of conversation-pilot (item 2, PDF, 2 pages, 81 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12149884&FileExtension=pdf&FileName=Record%20of%20interview-pilot_Redacted-Rel.pdf - Record of conversation-copilot (item 3, PDF, 1 page, 121 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12149768&FileExtension=pdf&FileName=Record%20of%20Interview-copilot-Rel.pdf - Post-accident engine run graph (item 4, JPG, 344 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14635452&FileExtension=JPG&FileName=Chart_engine_run-Rel.JPG - Post-accident engine run data (item 5, CSV, 937 B): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14635200&FileExtension=csv&FileName=Flt537_post_accident_engine_run-Rel.csv - Recorded engine data - last flight graph (item 6, JPG, 390 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14635381&FileExtension=JPG&FileName=Chart_last_flight_jan23_2021-Rel.JPG - Recorded engine data - last flight data (item 7, CSV, 127 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14634716&FileExtension=csv&FileName=Flt535_Jan_23_2021-Rel.csv - Investigative photos (item 8, PDF, 4 pages, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12151637&FileExtension=pdf&FileName=Investigative%20Photo%27s-Rel.pdf - Statement of party representatives to NTSB investigation (item 9, PDF, 1 page, 240 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12138481&FileExtension=pdf&FileName=party%20form_Redacted-Rel.pdf - Evidence control and wreckage release forms (item 10, PDF, 2 pages, 232 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12202373&FileExtension=pdf&FileName=Evidenace%20-%20wrecakge%20release%20forms_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.