2017 Quicksilver MXL II Accident in Hesperia, California

Accident Overview and Flight History On March 7, 2017, at 1018 Pacific standard time, an unregistered experimental amateur-built Quicksilver MXL II collided with terrain after takeoff from Hesperia Airport in Hesperia, California. The pilot, who was operating with an expired student pilot certificate, sustained fatal injuries, and the airplane sustained substantial damage. The flight was a test flight under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan had been filed. Friends reported that the pilot had been performing high-speed taxi tests for about two months prior to the accident, during which the airplane pulled to the left. A first flight test one month before the accident resulted in the airplane rolling left, departing the runway, and striking a hangar. The pilot spent the following month repairing the damage and conducting further taxi tests. On the day of the accident, a witness observed the pilot taxiing back and forth along the runway before initiating a takeoff roll from runway 3. After rotation, the airplane climbed to about 50 feet above ground level while drifting left of the runway centerline. It continued in a shallow climbing left turn, reached about 100 feet, transitioned to a 90-degree left roll, and rolled inverted into the ground. Video from an onboard GoPro HERO 5 camera showed the pilot performing an 80-second high-speed taxi along runway 21, during which the airplane veered left and right, crossing the centerline eight times. After turning around, the pilot accelerated down runway 3. The right wheel lifted off about 15 seconds later, followed by the left wheel. The airplane climbed level over the centerline for four seconds before banking left. The pilot moved the control stick to the right, and the ailerons responded correctly, with the right rudder cable going taut. Despite these inputs, the bank increased to about 45 degrees, the nose dropped, and the airplane transitioned into a spiral, striking the ground in a nose-down attitude after about three-quarters of a turn. The engine operated throughout the flight. The video also revealed the pilot had exclusive use of the runway and no other aircraft were in the traffic pattern. ## Personnel and Aircraft Information FAA records indicated the pilot was awarded medical certificates in 1979 and 1983, both marked valid for student pilot purposes only. At those examinations, he had no useful vision in his left eye and failed the color vision test in 1979 but passed it in 1983. His partner reported he was blind in his left eye at the time of the accident. Acquaintances stated he had flown ultralight aircraft for an extended period but did not keep records. His partner stated he had not flown recently and was considering attaining a private pilot certificate. The two-seat, high-wing airplane had a primary structure of fabric-covered metal tubing braced with flying wires. It was powered by a Rotax 582-series engine, serial number 9618333, mounted in a pusher configuration. No maintenance records were recovered. The pilot's partner stated he found the construction manual confusing and asked a friend to assist with construction tasks. He planned to register the airplane with the FAA once it was finished and flying. ## Wreckage and Impact Information The airplane came to rest about 750 feet beyond the runway 3 threshold and 315 feet left of the runway centerline. The airframe sustained crush and buckling damage from the nosewheel through to the main landing gear downtube and axle. Both wings and the empennage remained partially attached, and gasoline was present throughout the site. The primary load-carrying structure consisted of an aluminum root tube to which the engine, wings, king-post, and lower trike assembly were attached. The trike assembly supported the seats, landing gear, and cockpit controls, including an axle, axle struts, and a tri-bar assembly of steel cross- and down-tubes interconnected with slip-joints secured by AN4-series bolts. Under-wing flying wires were connected to the forward lower corners of the tri-bar assembly. Examination revealed the bolt securing the forward left tri-bar downtube to the upper tri-bar assembly was only attached to the upper assembly. The downtube was not fully inserted, being 1 1/4 inches short of full insertion, so the bolt only passed through the upper tube and rested against the upper end of the lower tube. Mating surfaces showed rust-colored corrosion and longitudinal striations consistent with movement, and the upper end of the lower tube displayed dimple marks from resting against the bolt shank. The interlocking assembly was wrapped with insulating foam and could not readily be observed by the pilot. ## Flight Recorders and Medical Information The GoPro HERO 5 camera, mounted on the tail structure facing forward, recorded the entire flight and multiple taxi tests from the days preceding the accident. In each recording, the pilot was unable to consistently keep the airplane tracking the runway centerline, and in one recording, the airplane departed the paved surface. The recordings showed the airplane was not equipped with a windshield, and although the pilot wore a helmet with a face shield, the shield was unused and in the up position throughout most taxi runs and the accident flight. An autopsy performed at the request of the San Bernardino County Sheriff's Department, Coroner Division, found the pilot's cause of death was multiple blunt force injuries, and the manner of death was accident. The pilot weighed 238 pounds and was 73 inches tall. His heart was significantly enlarged and thickened, weighing 615 grams, with an expected weight of 345 +/- 40 grams. The right ventricle was 0.3 cm thick, and both the lateral left ventricular wall and interventricular septum were 2.0 cm thick. Toxicology testing by NMS Labs of Willow Grove, Pennsylvania, on femoral blood identified ethanol, caffeine, nordiazepam, hydrocodone, dihydrocodeine, tetrahydrocannabinol (THC), tetrahydrocannabinol carboxylic acid (THC-COOH), methamphetamine, and amphetamine. Specimens tested by the FAA's Bioaeronautical Sciences Research Laboratory in Oklahoma City, Oklahoma, detected ethanol, acetaminophen, amphetamine, methamphetamine, carvedilol, dihydrocodeine, hydrocodone, hydromorphone, gabapentin, naproxen, nordiazepam, oxazepam, THC, and THC-COOH in various specimens. Nordiazepam and oxazepam are psychoactive metabolites of diazepam, a Schedule IV controlled substance. Hydrocodone is a Schedule II opioid analgesic, and dihydrocodeine and hydromorphone are its active metabolites. THC is the primary psychoactive compound in marijuana, and THC-COOH is its inactive metabolite. Methamphetamine is a Schedule II sympathomimetic, and amphetamine is its active metabolite. Carvedilol is a blood pressure medication, and gabapentin is an antiseizure medication. Naproxen is an anti-inflammatory analgesic. All these substances, except carvedilol and naproxen, are potentially impairing. Methamphetamine, hydrocodone, gabapentin, and most benzodiazepines are disqualifying for FAA aeromedical certification. Federal Aviation Regulations prohibit acting as a crewmember with 40 mg/dl or more alcohol in the blood, and marijuana may adversely affect pilot faculties. ## Follow-Up Examination A follow-up examination of the engine and airframe after recovery noted minor discrepancies, including inadequately tightened nuts and loose hardware. The left wingtip displayed evidence of repair, presumably from the earlier first test flight event. A witness to the first test flight stated the left side tail brace tube, connecting the wing trailing edge to the tail structure, was damaged during that event. He later observed the pilot working the tube and trying to straighten it out. Review of the accident video revealed the tube had not been replaced and was still bent at the time of the accident flight.