20150916016819A

On September 16, 2015, at approximately 0342 eastern daylight time (EDT), an experimental amateur-built vans RV-10, N122WK, was destroyed when it impacted trees and terrain following an uncontrolled descent in Alma, Georgia. The pilot/owner/builder and 4 passengers were fatally injured. Night visual

Meteorological conditions prevailed, and no flight plan was filed for the local personal flight which was conducted under the provisions of TITLE14 code of federal regulations part 91. According to the Bacon County sheriff's department, a search for the airplane was initiated at 0342 after a 911 emergency call, and was located approximately 6 miles east of the departure airport around 1630 that afternoon. Preliminary FAA radar data depicted a visual flight rules (1200 code) radar target maneuvering in the vicinity of the accident site between 03:29:52 and 03:31:59, at altitudes ranging between 2,200 feet mean sea level (MSL), and 2,900 feet MSL. The targets depicted an 's'-shaped ground track when plotted. The last few targets correlated to be the accident airplane showed a climb from 2,400 feet to 2,900 feet in 7 seconds, and then a descent down to 2500 feet 12 seconds later. This correlated to a climb rate greater than 3,000 feet per minute, and a descent rate of 2,500 feet per minute. AFS-760 airman records showed the pilot was issued a repairman experimental aircraft builder certificate on December 19, 2010 for the accident airplane. He was issued a third-class medical certificate on January 19, 2011 but a student pilot certificate was not issued concurrent with the medical. The pilot/owner/builder did not hold a pilot certificate and no pilot logbook was recovered; therefore, the pilot's total flight experience could not be determined. According to the aircraft maintenance log, the most recent condition inspection was completed on March 10,2015, at 338 total aircraft hours. The wreckage was examined at the accident site and all major components were accounted for at the scene. The wreckage came to rest on flat wooded terrain about 77 feet elevation. The wreckage path was approximately 200 feet long, and oriented about 240 degrees magnetic. The initial impact was in trees about 50 feet above the ground. The distance from the first tree strike to the impact crater was about 50 feet. The severed tree trunks and branches displayed angular cuts. A section of tree trunk about 6 feet long and 13 inches in diameter displayed clean, angular cuts at each end and was found about 200

Feet beyond the initial impact point. Another section of tree trunk was found nearby with sharp angular cuts, with a section of propeller blade embedded. The propeller blade section displayed an 's'bend and was fractured on both sides. The fracture surfaces displayed features consistent with overstress. The engine, cockpit, cabin area, and tail section were completely fragmented, and largely contained in and around the initial impact crater. The main wing spar was fractured in multiple pieces and lay on either side of the impact crater. Control continuity could not be confirmed due to the extensive impact-related damage. Wing tips, sections of aileron, seat cushions, and other small pieces

Associated with the airplane were located in a wide arc surrounding the accident site. The instrument panel, its associated components, and the cockpit controls could not be identified. An altimeter was found in the impact crater and displayed no useable data. The engine was severely damaged by impact. The engine case was fractured, and the accessories were all separated from their mounts. One propeller blade was found next to the engine, the propeller hub and

Remaining propeller blade was found buried in the impact crater beneath the engine. Both propeller blades displayed similar twisting, bending, leading-edge gouging, and chordwise scratching. The engine could not be rotated due to impact damage. Borescope examination of each cylinder and inside the crankcase revea