# NTSB CEN21LA181: Evolution Revolt, N565PK, Seminole, TX, April 6, 2021 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 3 · Limited · Final report - Date: April 5, 2021, 19:39 local (Apr 6, 2021, 00:39 UTC) - Place: Seminole, TX - Coordinates: 32.73507, -102.80049 - Nearby events: https://openairdocs.org/map.md?lat=32.7351&lon=-102.8005&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: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 102876 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA181 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102876/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102876 - Page: https://openairdocs.org/ntsb/CEN21LA181 ## Probable cause The student pilot’s loss of trike control while maneuvering at low altitude in gusting wind conditions, resulting in an impact with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Evolution REVOLT, 1 case](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=06001BM), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Evolution REVOLT, 1 case](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=06001BM), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [Evolution REVOLT, 4 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=06001BM), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/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: [Evolution REVOLT, 2 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=06001BM), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) ## Analysis The student pilot was maneuvering the weight-shift-controlled trike at low altitude over his residence. A witness who knew the pilot reported that the accident flight was at a lower altitude than she was accustomed to seeing the pilot fly. She said that the trike made a sharp turn, a gust of wind caught the trike, and she observed the pilot try to recover, but the trike descended and struck the ground. The nearest weather reporting station recorded wind conditions of 12 knots with gusts to 18 knots from 160º. Impact evidence was consistent with a left-wing-low impact. Examination of the airframe, engine, and systems found no preimpact anomalies that would preclude normal operation. A video of the accident flight provided by a witness showed the trike being maneuvered about 50 ft above the ground and making turns with bank angles of about 45°. The video reportedly ended about 20 seconds before the accident. A video the pilot had sent to the trike manufacturer showed the pilot make a series of turns just after takeoff that reached bank angles of about 80° at altitudes of about 30 ft above ground level. The two videos demonstrate the pilot’s lack of judgment regarding the dangers of aggressive maneuvering at low altitude. Toxicological testing of the pilot’s specimens identified diphenhydramine and alprazolam, which have potentially sedating effects. While the pilot may have had some effects from his use of these medications, it is unlikely that these effects contributed to the accident circumstances given the pilot’s history of lack of judgment concerning aggressive maneuvering at low altitude. Based on the available evidence, the accident was a result of the student pilot’s loss of trike control while maneuvering at low altitude in gusting wind conditions. ## Factual narrative The weight-shift-controlled trike used a high-mounted, strut-braced wing attached to a suspended frame which housed the pilot and one passenger in a tandem seating arrangement. The front seat position was used for piloting the trike and the engine and flight controls were accessible from this seat. The trike had a tricycle landing gear arrangement and was powered by a Rotax 912 ULS engine that had been modified from its original configuration with the addition of larger pistons and cylinders to increase the displacement of the engine. The increased displacement raised the power output of the engine to about 115 horsepower. On April 5, 2021, about 1939 central daylight time, an Evolution Revolt weight-shift trike, N565PK, was destroyed when it was involved in an accident near Seminole, Texas. The student pilot was fatally injured. The trike was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to a witness who knew the pilot and had seen the pilot flying on other occasions, the trike was flying at a lower altitude than usual and then it made a sharp low turn. She stated that the wind picked up right at that time and caught the wing. She saw the pilot try to recover, but the trike struck the ground. She stated that one wing and the area where the pilot footrest is located hit the ground first. A cell phone video provided by a witness showed the trike make a pass over the witness at an altitude of about 50 ft. The trike then made a 360° right turn with a bank angle of about 45°, which was followed by a 180° left turn with about the same angle of bank. The video ended as the trike appeared to be entering another right turn. It was reported that the end of the video was about 20 seconds before the accident occurred. Another video was provided by the manufacturer who reported that the accident pilot had sent him the video on October 26, 2020, after the pilot had purchased the trike and returned home. The video started with the trike on the ground with the engine running. The trike then accelerated and took off. Just after takeoff, the trike entered a series of low-altitude banked turns. During the turns, the trike was about 30 ft off the ground and the bank angles reached about 80°. Figure 1. Still frame image from a video of the accident trike preparing for takeoff on a previous flight. The video was sent by the pilot to the trike manufacturer. FIGURE 2. Still frame image of the accident trike just after takeoff on a previous flight. The video was sent by the pilot to the trike manufacturer. Toxicology testing was performed by the FAA Forensic Sciences Laboratory and identified diphenhydramine at 41 ng/mL, fluoxetine at 101 ng/mL and its metabolite, norfluoxetine at 198 ng/mL, and alprazolam at 79 ng/mL in cavity blood. All of these and the metabolite of alprazolam, alpha-hydroxyalprazolam were identified in urine as well. Diphenhydramine is a sedating antihistamine commonly sold with the name Benadryl and used totreat allergy and cold symptoms as well as to treat insomnia. Fluoxetine is an antidepressant that is not known to cause significant negative psychoactive performance effects in adults. Alprazolam is a sedating benzodiazepine used to treat anxiety. The pilot held a student pilot certificate that was issued on November 20, 2019. There were no pilot flight records recovered during the investigation. The pilot did not hold an FAA issued medical certificate. According to telephone conversations with the trike manufacturer, the pilot had purchased the trike about 1 year before the accident and had received flight training to the point of soloing at the manufacturer’s facility in Florida. Once the pilot had soloed, he did not receive further instruction from the trike manufacturer. There was no evidence that the pilot had received any additional instruction after the instruction received from the manufacturer. Based on the impact signatures, the trike impacted the terrain in a nose-low, left-wing low attitude consistent with the witness description. The left-wing leading edge spar was broken 4 ft from the wing tip and bent upward. The forward portion of the airframe cage exhibited rearward crushing damage, and the left landing gear was bent upward and rearward. All five propeller blades were fractured at their roots and the blade roots remained attached to the carbon fiber propeller hub. The hub was attached to the engine with a carbon fiber extension which was found separated around its circumference consistent with torsional failure. The ballistic parachute was out of its housing and lying on the ground adjacent to the trike, but the rocket motor had not been fired. A witness reported that the parachute came out after the trike impacted the ground. The trike maintenance records were not available for review. ## Aircraft - Registration: [N565PK](https://openairdocs.org/deregistered/N565PK-2023-03-04), registration cancelled 2023-03-04, S/N 001018, built 2019 (OpenAirDocs) - Reported make and model: EVOLUTION AIRCRAFT INC REVOLT - Registry model: [Evolution REVOLT](https://openairdocs.org/model/evolution-revolt) (registry code 06001BM) (OpenAirDocs) - Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs) - Category: Weight-shift - Serial number: 001018 - Year built: 2019 - Engines: Rotax 912ULS 115 hp reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental light sport (Special) - Departed: GNC, Seminole, TX - Airport: n/a - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: fatal; student; seat: front; restraint: 4-point ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 12 knots, gusting 18 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 45 °F - Altimeter: 29.82 inHg - Observed at: GNC, 10 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 20210405001689A](https://openairdocs.org/incident/20210405001689A), Apr 5, 2021: Evolution Aircraft Inc REVOLT, Seminole, TX, Destroyed, 1 fatal. On April 5, 2021 at 1939 CDT, an Evolution Revolt experimental aircraft bearing registration number [privacy data omitted], impacted terrain after failing to… ## Docket (10 files) The files NTSB released with the investigation on September 30, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102876. 12.7 MB in all. - Witness statement (item 1, PDF, 1 page, 898 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14357269&FileExtension=pdf&FileName=witness%20statement_Redacted-Rel.pdf - Witness video of accident flight prior to impact (item 2, 3GP, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14356952&FileExtension=3gp&FileName=MOV_5983-Rel.3gp - Roc with manufacturer (item 3, PDF, 1 page, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14360701&FileExtension=pdf&FileName=ROC%20with%20manufacturer-Rel.pdf - Roc with FAA (item 4, PDF, 1 page, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14361001&FileExtension=pdf&FileName=ROC%20with%20FAA-Rel.pdf - Weather information (item 5, PDF, 4 pages, 147 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14356756&FileExtension=pdf&FileName=METARS-Rel.pdf - Video sent to manufacturer by pilot on October 26 2020 (item 6, MOV, 6.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14357501&FileExtension=mov&FileName=IMG_2569-Rel.mov - Accident photos (item 7, PDF, 7 pages, 3.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14360603&FileExtension=pdf&FileName=Photo%201-Rel.pdf - Toxicological report (item 8, PDF, 2 pages, 635 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14356657&FileExtension=pdf&FileName=Pilot%20tox_Redacted-Rel.pdf - Autopsy memo (item 9, PDF, 1 page, 104 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14360432&FileExtension=pdf&FileName=Autopsy%20Memo%20for%20Record-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 10, PDF, 1 page, 305 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14357402&FileExtension=pdf&FileName=Signed%20Wreckage%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.