History of Flight
On May 20, 2021, about 1030 Pacific daylight time, an experimental amateur-built McClure Glasair III, registration N54CB, was substantially damaged when it impacted terrain near Eugene, Oregon. The pilot sustained serious injuries. The flight was conducted as a personal operation under 14 Code of Federal Regulations Part 91.
According to recorded automatic dependent surveillance-broadcast (ADS-B) data from the Federal Aviation Administration (FAA), the airplane departed runway 35 at Aurora State Airport (UAO), Aurora, Oregon, about 1007. It made a right turn onto a south-southwest heading and climbed to a cruise altitude of approximately 2,500 ft mean sea level (msl) en route to Mahlon Sweet Field Airport (EUG) in Eugene.
The pilot contacted Cascade approach control, and a controller cleared the airplane to land on runway 16R at EUG. The controller also cautioned the pilot about wake turbulence from landing traffic. About 8 nautical miles (nm) north of EUG, the airplane made a left turn consistent with a straight-in approach to runway 16 at EUG and began a descent, leveling off briefly at an altitude of 1,200 ft msl. ADS-B data indicated that, when the airplane was approximately 1.5 nm from the runway 16 threshold, it entered a left-hand spiral descent and continued to lose altitude. The airplane’s groundspeed was between 115 and 125 knots until about 1031, when the ADS-B data track ended, and the airplane was about 1.5 nm north of the accident site. During the approach to land, the pilot reported, “going down, going down.” No further radio communications were received. The airplane impacted tall grass about 1.5 nm north of EUG.
Witnesses in the surrounding area reported observing a low-flying airplane that made a banking turn before it disappeared.
Aircraft Information
A review of the airplane’s records showed that the landing gear had been inspected and returned to service on May 14, 2021; at that time, the tachometer indicated 188.1 hours. No evidence was found of any recent maintenance on the flaps, including the clevis pin and cotter key.
Wreckage and Impact Examination
Examination of the accident site revealed that the first identified point of contact was the left-wing tip. The wreckage continued for about 150 ft, where the engine was located. Flight control continuity could not be established due to impact damage and multiple separations. All major structural components were observed at the accident location.
Postaccident examination of the recovered airframe revealed that the entire wing assembly with landing gear separated from the fuselage in one piece. The left-wing flap actuator push-pull tube assembly was detached from the welded plate at the adjustable turnbuckle fork, but it remained attached to the flap actuator rod end at the wing-to-flap attachment. The left steel clevis pin and cotter key were not found. The right-wing flap hardware remained connected and intact from the flap tubular bar welded plate to the wing-to-flap attachment.
The engine crankshaft was manually rotated via the propeller, and mechanical and valve train continuity was established. The engine examination revealed no mechanical anomalies that would have precluded normal operation.