History of Flight
On June 8, 2019, at about 0938 Pacific daylight time, an experimental amateur-built Lockwood Aircraft Aircam airplane, N123GN, was substantially damaged when it crashed in Hemet, California. The pilot was fatally injured. The flight was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot’s friends, the accident flight was the first test flight after the pilot had received a special airworthiness certificate one week earlier, allowing him to begin Phase I flight testing. On the morning of the accident, the pilot’s friends had gathered to watch his first flight. The pilot lined up the airplane on the runway centerline and began a slow ground roll for a few seconds before advancing the throttles to takeoff power. A few seconds later, during takeoff, the airplane reached about 20 ft above ground level, at which point the left wing folded upward. The airplane immediately rolled left, descended, and impacted the ground inverted. A review of a video of the accident recorded by a witness corroborated the witness interviews.
Aircraft Information
The pilot purchased the airplane kit in 2017. Two friends assisted during the build process: one an airframe and powerplant mechanic who provided instructional assistance, and the other who assisted by collecting tools, holding heavy objects, wiring, and riveting. The mechanic stated that he would demonstrate part of the process for the pilot, who would then complete the work. After the wings were initially installed, they performed a wind test and then removed the wings. While reinstalling them, they put the struts on backward and had to remove them again. After this was corrected and the wings were again reinstalled, they found another discrepancy that required another removal and reinstallation. The mechanic recalled that the left wing may have been removed one more time after that. During each removal and installation, the pilot's friends would help jack the wing up while the pilot removed or installed the struts and hardware. The mechanic added that he would periodically remind the pilot to "check every bolt and nut and screw, everything." Although the pilot did what was asked, the mechanic continued to find loose screws and nuts on the airplane throughout the build process.
According to the Aircam Construction manual, Section 12, "Airframe Assembly & Rigging," the wings are secured to the fuselage by forward and rear lift struts that are bolted to attachment fittings on the center fuselage. During construction, the builder must lift the wing and fit the forward strut over the attachment fitting, then insert an AN5-16A bolt through the strut and attachments and secure them with AN960-516 washers and AN365-524 nuts torqued to 30 inch-lbs.
Wreckage and Impact
The airplane came to rest inverted on the left runway edge, about 550 ft from the approach end of the runway. All major sections of the airframe were accounted for at the accident site. The debris path was oriented on a magnetic heading of 219°, and the initial impact point was marked by short parallel gouges in the runway about 125 ft from the main wreckage, which was positioned on a 111° magnetic heading. Multiple dents and compression wrinkles were observed on both sides of the forward fuselage at the nose cone, which was scarred and cracked along the top. The fuselage frame at each wing strut attachment was compressed on both sides. The left wing was partially separated and folded beneath the main wreckage, with the wing tip adjacent to the empennage. The right-wing compression tube was deformed, and the leading edge was crushed. Fuel stains were observed below the left wing on the runway surface.
An examination revealed that the left aileron control tube was continuous from the cockpit to its respective control surface through a fracture in the aileron push/pull tube and a fracture at the wing root. The rudder, elevators, and right aileron were traced from the control surfaces to their flight controls in the cockpit. A measurement of the elevator trim tab jackscrew displayed 5/8 of an inch of exposed thread, which the manufacturer stated was consistent with a neutral trim position.
The forward and rear left-wing lift struts remained connected to the wing but were not attached to the fuselage attachment fittings. Further examination revealed that the bolts were present and secured to the lift struts with washers and nuts but had not been connected to the fuselage through the attachment fittings. The fittings on the fuselage were intact, and their corresponding bolt holes were undamaged. The forward and rear right-wing struts were properly attached to the fuselage attachment fittings, and the hardware was secure. During a subsequent test, the struts felt secure after they were reinstalled to the lift strut attachment fittings as they were during the accident flight, without the bolts running through the lift strut attachment fittings. The struts were then reinstalled with the bolts running through both the lift struts and attachment fittings in accordance with the manufacturer's rigging manual and felt secure when investigators tried to pull them from the fitting.
Additional Information
FAA Advisory Circular (AC) 90-89B, "Amateur-Build Aircraft and Ultralight Flight Testing Handbook," issued on April 27, 2015, provided assistance to amateur builders in developing individualized aircraft flight-test plans; however, the AC was not mandatory. Appendix 1 of the AC, "Sample Checklist for a Condition Inspection," included items specifically for the wings, including the wing attachment points and the wing, strut, and cable attachments and hardware for safety and condition.
FAA Order 8130.2, "Issuing Special Airworthiness Certificates," section 4-6, stated that the Designated Airworthiness Representative (DAR) must review the application and inspect the aircraft before issuing an airworthiness certificate. The order did not provide a list of required inspection items nor was it the DAR’s responsibility to provide one. The pilot contacted a manufacturing DAR (DAR-F) in October 2018 to "get a head start" on the certification process. The DAR-F sent the pilot several forms and instructions and provided a generic inspection checklist that included a section titled "General Condition – Fuselage, Wing, Tail Assembly" with 13 checklist items, none of which addressed the wing struts. On June 1, 2019, the DAR-F completed his review and inspection and issued the special airworthiness certificate on the same day; at that time, the airplane had 7.6 total flight hours. The DAR-F reported that he followed FAA Order 8130.2 and inspected the strut for hardware security, general condition, thread engagement, position, and tightness. He found two discrepancies—a loose jam nut and frayed throttle cable ends—but noted that he did not feel uncomfortable issuing the certificate.
Medical and Pathological Information
The Riverside County Sheriff's Department Coroner-Public Administrator's Office performed an autopsy on the pilot. The cause of death was multiple blunt impact injuries. No significant natural disease was identified. Toxicology testing of the pilot’s tissue specimens performed at the FAA's Bioaeronautical Sciences Laboratory were negative for illicit drugs, ethanol, and combustion products.