History of Flight
On December 21, 2021, at about 0926 central standard time, a Cessna 208B airplane, registration N1116N, collided with a powered paraglider while in flight near Fulshear, Texas. The pilot of the Cessna and the non-certificated powered paraglider operator were fatally injured. The Cessna was destroyed, and the powered paraglider sustained substantial damage. The Cessna was operating as a Title 14 Code of Federal Regulations (CFR) Part 135 cargo flight, and the powered paraglider was operating as a Title 14 CFR Part 103 personal flight.
According to air traffic control data, around 0910, the Cessna departed George Bush Intercontinental Airport (IAH), Houston, Texas, and flew southwest toward Victoria Regional Airport (VCT), Victoria, Texas. At 0917:53, the Cessna pilot was cleared to climb and maintain 5,000 ft mean sea level (msl). At 0924:08, the pilot asked the controller to confirm the assigned altitude, and the controller replied to remain at 5,000 ft msl with an expectation of a higher altitude soon.
ADS-B track data showed that between 0925:31 and 0925:34, the Cessna departed level flight at 5,000 ft msl and entered a rapidly increasing descent. At 0925:34, the final recorded ADS-B point was at 4,725 ft msl, about 0.5 mile northeast of the main wreckage site, with a descent rate of about 8,960 feet per minute.
The powered paraglider was not equipped with a transponder or ADS-B OUT transmitter; its position was not displayed on the air traffic controller's display. Postaccident review of radar data revealed sporadic primary returns near where the Cessna departed level flight, but these were not displayed and had no reported altitude.
The powered paraglider operator was using a video camera that captured the final 7 minutes 13 seconds of the flight. The video showed the operator's view of the paraglider rigging and wing. The audio track was not aligned with the video and was deemed not relevant.
Review of the camera footage showed no anomalies until the final 8 seconds. At 7 minutes 6 seconds into the recording, the operator turned his head about 45° to the right, consistent with his attention being drawn to something to the right. His attention remained to the right during the final 8 seconds. About 6 seconds before the collision, he pulled the left control toggle and turned toward a northwest heading. The profile of a high-wing airplane, later identified as the Cessna 208B, emerged slightly above the horizon to the right. About 3 seconds before the collision, he aggressively pulled down on both control toggles. About 1 second before the collision, he relieved pressure on the left toggle and sharply pulled down on the right toggle to enter a right turn. The Cessna remained in level flight with no apparent change in roll or heading. In the final moments, the powered paraglider remained in a steep right turn, and the operator's head stayed sharply to the right as the Cessna converged.
The final video frame showed the powered paraglider in a steep right bank, the operator's head rotated about 45° to the right, and his hands on the control toggles. The Cessna's right-wing leading edge, outboard of the lift strut attachment, appeared inline with the operator's body. The Cessna's flight path appeared straight and level.
Meteorological Information
Based on the video footage, visual meteorological conditions prevailed with no clouds or visibility restrictions. At the time of the accident, the sun's position relative to the accident site was to the southeast (137° true) and about 22.3° above the horizon.
Wreckage and Impact Information
An onsite examination revealed that the outboard 10 ft of the Cessna's right wing separated following impact with the powered paraglider. The separated section was located about 0.6 mile east of the main wreckage site. There was a semicircular impact impression in the leading edge of the right wing outboard section, measuring about 5 ft wide and 36 inches deep. Fabric remnants resembling the powered paraglider operator's jacket were found within the impression.
The Cessna impacted terrain at high vertical speed in a steep nose-down and inverted attitude on a 332° magnetic heading. The wreckage was highly fragmented in a 10-ft-deep impact crater. Flight control continuity could not be established due to fragmentation; all flight control cable separations were consistent with tensile overload. The engine and propeller were at the base of the crater. All three propeller blades had separated from the hub and exhibited leading edge gouging and chordwise scoring; two blades showed S-shape bending.
The powered paraglider operator and the paraglider engine were found about 0.7 mile east-northeast of the Cessna's main wreckage site. The operator had separated from his seat-style harness. The paraglider wing, harness, and emergency parachute were located about 3.9 miles south of the main wreckage site. The harness exhibited tearing and impact damage; static and control lines remained intact. The wing remained intact with minor tearing of the lower surface. The emergency parachute was deployed, intact, with no tearing or damage.
Additional Information
The Cessna was operating under 14 CFR Part 135 on an instrument flight plan in visual meteorological conditions. It was equipped with a transponder and ADS-B OUT transmitter, making it visible to air traffic control. The powered paraglider was operating as an ultralight vehicle under 14 CFR Part 103. In the United States, ultralight vehicles are not identified as aircraft and do not require FAA registration, airworthiness certificate, or pilot certificate.
According to 14 CFR Part 91.227 and Advisory Circular 20-165B, an aircraft registration number and ICAO 24-bit address are required for ADS-B OUT installation in civil aircraft. Ultralight vehicles without FAA registration are not authorized to use ADS-B OUT transmitters. The collision occurred in Class E airspace, which did not require two-way radio communication, a transponder, or ADS-B OUT for the powered paraglider.
Neither aircraft was equipped with ADS-B IN technology, cockpit display of traffic information, or a traffic alerting system.
According to 14 CFR Part 103.13, an ultralight vehicle shall maintain vigilance to see and avoid aircraft and shall yield the right-of-way to all aircraft. No person shall operate an ultralight vehicle in a manner that creates a collision hazard.
Medical and Pathological Information
Cessna Pilot
The Cessna pilot's last aviation medical examination was on June 14, 2021, when he reported no medication use. He had a history of anxiety due to legal issues and family stress, and a 2008 court-martial with dishonorable discharge from the Air Force. He had used trazodone in 2008 and was issued a FAA Letter of Eligibility in 2011. No significant issues were identified at his last exam, and he received a first-class medical certificate without limitation.
An autopsy performed by the Fort Bend County Medical Examiner Office listed the cause of death as multiple blunt force trauma, manner of death accident. The ability to evaluate for natural disease was extremely limited by traumatic injury. Toxicological testing by the FAA Forensic Sciences laboratory detected the prescription antipsychotic medication quetiapine in muscle tissue. Ethanol was detected in one muscle specimen at 0.022 g/dL but not in another. No blood was available. Quetiapine (marketed as Seroquel) is an antipsychotic that can cause drowsiness and impair judgment, thinking, and motor skills. The FAA considers quetiapine a "do not issue/do not fly" medication. The pilot's primary care records from three years before the crash did not document quetiapine use, psychiatric disorder, or substance abuse. Ethanol can be produced postmortem, especially with extensive injury.
Powered Paraglider Operator
An autopsy by the Fort Bend County Medical Examiner Office listed the cause of death as blunt force injuries, manner of death accident. No significant natural disease was identified. Toxicological testing detected no ethanol or tested-for drugs.
Tests and Research: Inflight Collision Study
Based on video evidence, the Cessna approached the powered paraglider's right side at an estimated 90° collision angle. ADS-B data indicated the Cessna was traveling at 162 knots groundspeed before the collision. The powered paraglider's trim speed range was 21-27 knots, estimated at about 24 knots. The closing speed was about 164 knots.
About 8 seconds before collision, the powered paraglider operator turned his head to the right and continued looking that direction. About 6 seconds before, he began maneuvering to avoid the converging Cessna.
FAA Advisory Circular 90-48E indicates that about 12.5 seconds can elapse between seeing a conflicting aircraft and beginning an avoidance maneuver under optimal conditions. The subtended visual angle of the Cessna's 52 ft wingspan from the paraglider operator's view at 8 seconds was about 1.35°, similar to a thumbnail at arm's length. Visual acuity drops dramatically beyond 2° from the center of fixation; the Cessna would have had little apparent motion on a collision course.
From the Cessna pilot's view, the powered paraglider would have appeared vertically centered and about 8.4° left of center. The windscreen center post did not obstruct the view. The Cessna pilot did not attempt to maneuver. The powered paraglider's wing chord (about 7 ft) was the widest visible dimension. At 17.5 seconds before collision, the subtended angle was 0.083°; at 12.5 seconds, 0.116°. Based on video, the paraglider was superimposed on a complex background. Research suggests a minimum subtended angle of 0.20° for recognizing an uncommon shape in distractors, which would have occurred about 7.4 seconds before collision. Considering low contrast (white/blue wing against bright sky, dark operator against terrain), the recognition angle may have been 0.4° to 0.6°, corresponding to 2-3 seconds before collision.
Limitations of Visual Scanning
Visual acuity is low beyond 2° from fixation. The FAA recommends separate fixations at least 10° apart, each at least one second. An ATSB study noted that systematically scanning a 180° by 30° area would take 54 seconds, making systematic scanning impractical. A mathematical model estimated a 30% likelihood of detecting a 40 ft aircraft with a 200 knot closing speed. Research shows pilots do not scan systematically; general aviation pilots may only scan outside 30-50% of the time. A study using actual flights with an intruder found an 85% probability of detection within 12 seconds or less before collision at a 120 knot closing speed.