# NTSB CEN21LA008: Stephens William E Quicksilver MXL-2 Sport, N2942A, Mount Vernon, IN, October 6, 2020 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 3 · Limited · Final report - Date: October 6, 2020, 08:20 local (13:20 UTC) - Place: Mount Vernon, IN - Coordinates: 37.920396, -87.7663 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.9204&lon=-87.7663&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-aerobatics: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 102099 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA008 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102099/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102099 - Page: https://openairdocs.org/ntsb/CEN21LA008 ## Probable cause The pilot’s exceedance of the airplane’s critical angle of attack during an aerobatic maneuver, which resulted in an aerodynamic stall and spin and loss of control. Contributing to the accident was the pilot’s decision to perform aerobatic maneuvers in an airplane that was not approved to do so. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot; cases with it: [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Aircraft capability](https://openairdocs.org/ntsb-findings/01061000): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [All aircraft, 57 cases](https://openairdocs.org/ntsb-findings/01061000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-aerobatics: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) ## Analysis The sport pilot and pilot-rated passenger were conducting a local flight in the light sport airplane, which was not approved for aerobatic flight. A witness near the accident site saw the airplane exit a loop then spiral toward the ground. The airplane impacted the ground on a southwesterly heading and came to rest about 100 ft from the initial impact point. The flight controls were intact and there were no mechanical malfunctions or anomalies with the airplane that would have precluded normal operation. Toxicological testing detected memantine in specimens from the pilot, which is used to treat dementia. The pilot’s presumed underlying dementia could have influenced some of his decision-making but without more information about the status of his disease, its effect on the safety of his flying could not be determined. Specimens from the pilot-rated passenger detected diphenhydramine, THC, and its metabolites; however, the low levels of each substance were unlikely to have caused impairing effects. Overall, it is unlikely the pilot’s presumed dementia, or the pilot-rated passenger’s use of multiple substances contributed to the circumstances of this accident. The circumstances of the accident are consistent with the pilot’s decision to perform aerobatic maneuvers in an airplane not approved for aerobatic flight, during which he exceeded the airplane’s critical angle of attack, resulting in an aerodynamic stall/spin and loss of control. ## Factual narrative The airplane was not approved for aerobatic flight per the experimental operating limitations. . On October 6, 2020, about 0820 central daylight time, a Quicksilver MXL-2 Sport light sport airplane, N2942A, was substantially damaged when it was involved in an accident near Mount Vernon, Indiana. The sport pilot and pilot-rated passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. A witness stated that she saw the accident airplane flying in the area. She watched the airplane come out of a loop then spiral toward the ground. She did not see the airplane impact the ground, but when the airplane was out of view, she heard the sound of an impact. She observed the airplane from her residence, which was 0.33 nautical mile (nm) east of the accident site and about 1 nm northeast of the airport. An autopsy of the sport pilot was performed by the Posey County Coroner's Office, Mt. Vernon, Indiana. The cause of death was multiple blunt force injuries. The FAA's Forensic Sciences Laboratory performed toxicology tests on specimens from the pilot; memantine was detected in the blood and liver. Memantine is used to treat confusion (dementia) related to Alzheimer's disease. An autopsy of the pilot-rated passenger was performed by the Posey County Coroner's Office, Mt. Vernon, Indiana. The cause of death was multiple blunt force injuries. The FAA's Forensic Sciences Laboratory performed toxicology tests on specimens from the passenger; glucose, diphenhydramine, carboxy-delta-9-THC, 11-hydroxy-delta-9-THC were detected in the urine, and diphenhydramine, delta-9-THC, and carboxy-delta-9-THC were detected in the blood. The pilot, who was the owner of the airplane, was seated in the right seat. The pilot-rated passenger was seated in the left seat. Both occupants were eligible to fly the light sport airplane with a valid driver’s license. An individual who had flown with the pilot about 1 year before the accident recounted that the pilot performed several “dangerous maneuvers” that made him very uncomfortable. He added that the pilot had “good technical skills, but his decision making was very poor.” Another individual had just flown with the pilot in the days before the accident. She reported that the pilot made low passes and dives. She captured numerous photos and videos of these flights from the ground and while flying in the airplane and provided them for the investigation. A review of the videos revealed that the pilot performed several steep climbs and steep descents at low altitude over the runway. Other videos showed the pilot maneuvering the airplane through a small opening in a tree line while on base to final approach for landing. The airplane impacted a harvested crop field oriented on a southwesterly heading and came to rest on its right side. The main wreckage was located about 100 ft from the initial ground impact marks. The engine remained attached to its mount and onepropeller blade had separated from the propeller hub. The responding Federal Aviation Administration (FAA) inspector reported that the flight controls were connected and noted no anomalies. The airplane’s metal tubular structure was bent in several places from the impact. The FAA inspector retained a section of fractured tubular structure for examination. There were no other anomalies noted with the airplane or engine. The NTSB Materials Laboratory examined the fractured pieces of structure, which consisted mainly of anodized aluminum tubular supports that were bolted together with a steel alloy bolt. The bolt fracture surface exhibited rupture consistent with overstress fracture. ## Aircraft - Registration: N2942A (not matched to a registry record) - Reported make and model: STEPHENS WILLIAM E Quicksilver MXL-2 Sport - Category: Airplane, amateur-built - Serial number: 001 - Year built: 1993 - Engines: Rotax 582 64 hp reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Unknown - Airport: 59II, Posey Patch Ultralight Flightpark - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 75; injuries: fatal; sport pilot, student; seat: right; toxicology performed - Pilot-rated passenger; age 57; injuries: fatal; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; seat: left; toxicology performed; flight hours: 2,020 total ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 46 °F - Altimeter: 30.14 inHg - Observed at: KEHR, 8 nm away - METAR: KEHR 061356Z AUTO 22005KT 10SM CLR 12/08 A3014 RMK AO2 SLP209 T01220083 ## 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 20201006017259A](https://openairdocs.org/incident/20201006017259A), Oct 6, 2020: Stephens William E QUICKSILVER, Mt Vernon, IN, Destroyed, 2 fatal. On Tuesday, 10/06/2020, at approximately 9:20 a.m. eastern standard time, a Quicksilver MXL-2 light sport aircraft impacted terrain approximately 1 mile… ## Docket (13 files) The files NTSB released with the investigation on June 2, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102099. 333 MB in all. - Witness interview transcript (item 1, PDF, 7 pages, 75 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11675959&FileExtension=pdf&FileName=Witness%20interview%20transcript_Redacted-Rel.pdf - Witness statement - previous passenger (item 2, PDF, 1 page, 162 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11749670&FileExtension=pdf&FileName=Email%20-%20Gwendolyn%20Waters%20(flew%20with%20pilot)_Redacted-Rel.pdf - Correspondence - witness statements (item 3, PDF, 3 pages, 494 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12790335&FileExtension=pdf&FileName=ROCs%20-%20all_Redacted-Rel.pdf - FAA inspector's examination summary (item 4, PDF, 1 page, 151 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12791615&FileExtension=pdf&FileName=Memo%20For%20Record%20-%20FAA%20exam-Rel.pdf - Experimental operating limitations (item 5, PDF, 9 pages, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12863409&FileExtension=pdf&FileName=Experimental%20operating%20limitations_Redacted-Rel.pdf - Materials laboratory factual report (item 6, PDF, 17 pages, 22 photos, 5.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12375388&FileExtension=pdf&FileName=21-037%20-%20Materials%20Lab%20Factual%20Report%20(CEN21LA008)-Rel.pdf - Photos (item 7, PDF, 5 pages, 11.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12791322&FileExtension=pdf&FileName=Photos-Rel.pdf - Video file - previous flight with accident pilot (item 8, MOV, 179 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12790821&FileExtension=MOV&FileName=IMG_8279-Rel.MOV - Video file - previous flight with accident pilot (landing) (item 9, MOV, 136 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12791087&FileExtension=MOV&FileName=IMG_7451-Rel.MOV - Autopsy memo - pic/owner (item 10, PDF, 1 page, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12793426&FileExtension=pdf&FileName=Autopsy%20Memo%20for%20Record%20-%20Pilot-Rel.pdf - Autopsy memo - pilot-rated-passenger (item 11, PDF, 1 page, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12793557&FileExtension=pdf&FileName=Autopsy%20Memo%20for%20Record%20-%20Second%20Pilot-Rel.pdf - Toxicological report - pilot (item 12, PDF, 1 page, 165 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11675106&FileExtension=pdf&FileName=Tox%20-%20pilot_Redacted-Rel.pdf - Toxicological report - pilot-rated-passenger (item 13, PDF, 1 page, 198 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11675603&FileExtension=pdf&FileName=Tox%20-%20passenger_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.