# NTSB CEN18FA004: Aero Vodochody L39C, N580LL, Vernon, TX, October 8, 2017 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: October 8, 2017, 13:00 local (18:00 UTC) - Place: Vernon, TX - Coordinates: 34.211666, -99.289169 - Nearby events: https://openairdocs.org/map.md?lat=34.2117&lon=-99.2892&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report May 29, 2019 - Report: Approved by Office Director - NTSB office: Central Region - NTSB case key (mKey): 96157 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN18FA004 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96157/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96157 - Page: https://openairdocs.org/ntsb/CEN18FA004 ## Probable cause An in-flight loss of control and collision with terrain for reasons that could not be determined based on the available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Aero Vodochody L39C, 2 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=05620RN), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Aero Vodochody L39C, 2 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05620RN), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Aero Vodochody L39C, 3 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=05620RN), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Aero Vodochody L39C, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=05620RN), [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 control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Aero Vodochody L39C, 3 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=05620RN), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Aero Vodochody L39C, 2 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=05620RN), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The commercial pilot of the jet trainer airplane departed on a local personal flight and flew for about an hour before returning to the airport. Witnesses saw the airplane make a high-speed pass over the runway at low altitude. Some thought the pilot may have been conducting a go-around. The airplane then entered a steep left bank, estimated to vary between 45° and 90°, then impacted the ground. The airplane was destroyed by impact and a postcrash fire, which precluded a thorough examination of its systems, including the flight controls; however, the engine displayed signatures of power production at the time of impact. Toxicology testing and autopsy of the pilot did not detect any impairing substances or identify significant physiological issues that may have resulted in incapacitation. It is likely that the pilot experienced an in-flight loss of control while maneuvering at low altitude; however, the reason for the loss of control could not be determined based on the available information. ## Factual narrative The airplane was manufactured in Czechoslovakia in 1984. It was designed as a training aircraft for Warsaw Pact countries. The airplane was equipped with an Ivchenko AI-25-TL turbofan engine, rated at 3,792 lbs of thrust. The most recent condition inspection of the airplane and engine was completed on August 8, 2017, at an airframe and engine total time of 1,440.5 and 894.7 hours, respectively. At that time, the engine had accrued 107.7 hours since last overhaul. The transponder, altimeter, and encoder were also checked and re-certified. On October 8, 2017, about 1257 central daylight time, an Aero Vodochody L39C, N580LL, collided with terrain 1/2 mile south of Wilbarger County Airport (F05), Vernon, Texas. The commercial pilot was fatally injured and the airplane was destroyed. The airplane was owned and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed for the local personal flight, which originated from F05 about 1153. There were eight witnesses to the accident, and their accounts of the sequence of events varied. All the witnesses agreed that the airplane made a pass over runway 20; estimates of the airplane's altitude varied from 50 to 300 ft above ground level. One witness thought the airplane may be conducting a go-around. The airplane then made a sharp left bank; witnesses estimated the bank angle between 45° and 90°. Two witnesses thought that the pilot was trying to do a "barrel roll." One witness stated that the airplane entered an inverted attitude and "spun to the ground"; other witnesses stated that the left wing hit the ground before the airplane impacted terrain. Another witness, who was driving north along the highway adjacent to the airport, saw the airplane fly by at low altitude. He stated that the airplane's nose came up slightly and that it entered a steep left bank such that, "you could see the whole profile." He then saw a fireball and black smoke. A GoPro camera was recovered from the wreckage and sent to NTSB's Vehicle Recorders Division. The GoPro had a 64GB internal microSD card that was catastrophically damaged during the accident; the data was unrecoverable. The Office of the Chief Medical Examiner, Tarrant County, Texas, performed an autopsy on the pilot. The pilot's death was attributed to "multiple traumatic injuries due to (an) airplane crash." The toxicology report was negative for ethanol and drugs. Carbon monoxide tests could not be performed. Although thermal injuries were present, the trachea showed no soot deposition. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing on specimens of the pilot. Testing revealed 24 (mg/dL) ethanol in muscle tissue; however, putrefaction of the samples was noted, and the ethanol was likely from sources other than ingestion. Additionally, ondansetron was detected in liver andmuscle tissue. Ondansetron (Zofran) is a non-sedating serotonin 5-HT3 receptor antagonist used mainly as an antiemetic to treat nausea and vomiting. The 1255 automated observation at F05 recorded wind from 210° at 14 knots, 10 miles visibility, clear skies, temperature 28°C, dew point 6°C, and an altimeter setting of 29.70 inches of mercury. The pilot held a commercial pilot certificate with ratings for airplane single- and multi-engine land and instrument airplane. He also held a type rating in the Aero Vodochody L39. His second-class Federal Aviation Administration airman medical certificate, dated August 25, 2017, contained the restriction, "Must wear corrective lenses." On the application for that medical certificate, the pilot estimated that he had accrued 1,124 total hours of flight experience, 17 hours of which were accrued in the previous six months. The on-scene investigation revealed a 40-ft long ground scar, consistent with the left wing contacting the ground, which led to a 50-ft long crater. The airplane broke apart, leaving a 580-ft long debris path aligned on a 170° magnetic heading. There was evidence of a flash fire of the surrounding grass likely ignited by vaporized fuel. The airplane itself was fragmented and burned. The right wing separated, and the aileron was missing. The left wing was destroyed. The empennage was identified. The engine compressor showed signatures consistent with rotation followed by sudden stoppage. The guide vanes were broken or crushed, and there was scoring of the engine case. Flight control continuity could not be established due to impact damage, but pushrod movement was identified when the elevators and rudder were moved by hand. ## Aircraft - Registration: [N580LL](https://openairdocs.org/deregistered/N580LL-2017-12-29), registration cancelled 2017-12-29, S/N 432921, built 1984 (OpenAirDocs) - Reported make and model: Aero Vodochody L39C - Registry model: [Aero Vodochody L39C](https://openairdocs.org/model/aero-vodochody-l39c) (registry code 05620RN) (OpenAirDocs) - Registry engine: [Ivchenko AI-25TL](https://openairdocs.org/engine/ivchenko-ai-25tl) (registry code 34703, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 432921 - Year built: 1984 - Airframe hours: 1441 - Engines: Ivchenko AI-25TL 3792 lbs thrust turbo fan - Damage: Destroyed - Fire: On-Ground - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, August 8, 2017 - Departed: F05, Vernon, TX - Destination: F05, Vernon, TX - Airport: F05, Wilbarger County, runway 20, 5,099 × 100 ft, asphalt - Equipment: Electronic primary flight display, Electronic multifunction display, Auto-pilot, ADS-B, Onboard weather ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: fatal; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; seat: front; restraint: 4-point; toxicology performed; flight hours: 1,124 total, 8 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 14 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 43 °F - Altimeter: 29.70 inHg - Observed at: KF05, 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 20171008011519A](https://openairdocs.org/incident/20171008011519A), Oct 8, 2017: Aero Vodochody L39C, Vernon, TX, Destroyed, 1 fatal. On October 8, 2017, N580LL, an Aero Vodochody L39C, crashed in a field and consumed by post impact fire, approximately a 1/2 mile south of Wilbarger County… ## Docket (6 files) The files NTSB released with the investigation on April 5, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96157. 4.1 MB in all. - Witness Statements (item 1, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40471693&FileExtension=.PDF&FileName=Witness%20Statements-Master.PDF - Record of Conversation, Trent Townson (item 2, .PDF, 94 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40471694&FileExtension=.PDF&FileName=Record%20of%20Conversation,%20Trent%20Townson-Master.PDF - Electronic Devices - Specialist's Factual Report (item 3, .PDF, 61 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40471695&FileExtension=.PDF&FileName=Electronic%20Devices%20-%20Specialist%27s%20Factual%20Report-Master.PDF - Toxicology Report (item 4, .PDF, 92 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40471696&FileExtension=.PDF&FileName=Toxicology%20Report-Master.PDF - NTSB Form 6120.15, Release of Wreckage Related to CEN18FA004 (item 5, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40471697&FileExtension=.PDF&FileName=NTSB%20Form%206120.15,%20Release%20of%20Wreckage%20Related%20to%20CEN18FA004-Master.PDF - Report Photos (item 6, .PDF, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40471698&FileExtension=.PDF&FileName=Report%20Photos-Master.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.