Accident Overview
On June 4, 2017, about 0824 mountain daylight time, an Excaliber experimental light sport airplane, registration N78DZ, was substantially damaged when it impacted terrain near Albuquerque, New Mexico, during an emergency landing due to flight control anomalies. The commercial pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The airplane was registered to the pilot, and the personal flight was conducted under Title 14 Code of Federal Regulations Part 91. The local flight originated at 0715 from Double Eagle Airport (AEG), Albuquerque, New Mexico, and was en route back to AEG when the accident occurred.
Pilot Report
According to the pilot, he had been flying a little over an hour without any problems since takeoff from AEG. While flying straight and level at about 75 mph (below never-exceed speed), the pitch control became erratic. The control stick started "slamming" fore and aft to the limits, the airplane nose began pitching up and down, and the airplane began buffeting "like it was going to come apart." The pilot declared an emergency and reduced airspeed to 50 to 60 mph, which slightly lessened the fore and aft stick movement and pitch, but did not control it. The pilot turned to clear steep terrain and chose a relatively flat field for an emergency landing. He was able to make final directional corrections and flew the airplane to landing at about 40 to 45 mph and a rate of descent of 200 to 300 ft per minute. The airplane remained upright, but the nose gear and the left main gear sheared off, the airplane turned 180°, and the left wing and horizontal stabilizer struck the ground.
Post-Accident Examination
Examination of the aircraft by a Federal Aviation Administration inspector and the pilot after the accident revealed a broken right elevator control rod. The left elevator control rod was not broken. The control rod that separated was a factory-supplied, 1/2-inch aluminum tube with bearings at each end. The attach points of the control rods appeared to be intact. The bearings were still connected and safety wired, and all other control rod linkages and attach points were connected. There was normal movement of the left elevator control system (rod still intact). The damaged control rod (right elevator) and the intact control rod (left elevator) were compared and examined by a National Transportation Safety Board structures engineer. According to the engineer, there was no indication of any pre-existing failure on the fracture surface of the right elevator control rod. The deformation of the rod was indicative of a bending failure of the rod.
Pilot Comment
The pilot reported after the accident that he may have encountered flutter.