WPR12LA407

The pilot’s inability to maintain control of the airplane following the loss of aileron and elevator control due to the forward flight control torque tube assembly’s detachment from the forward bearing. Contributing to the accident was the inadequate construction of the forward bulkhead that held the flight control torque tube assembly in place and the improper installation of the thrust bearings.

During the aerobatic practice flight, the airplane departed controlled flight. The pilot opened the canopy, which then separated from the airplane, and exited the airplane. Due to the low altitude, the pilot's parachute did not fully deploy before he impacted the ground. The accident airplane was 1 of 14 MX-model airplanes. It was the only model built from a kit as an experimental, amateur-built aircraft, and it was constructed differently than the other MX-model airplanes. Postaccident examination of the torque tube assembly revealed that the forward bulkhead holding the torque tube assembly in place was constructed in a way that allowed the bulkhead to flex, which subsequently led the torque tube assembly to detach from the forward bearing during the accident flight and resulted in the loss of aileron and elevator control. Examination also revealed that the forward and aft bearing houses were installed opposite of the correct direction, which allowed the bearings to detach from the torque tube assembly when the front bulkhead flexed.

HISTORY OF FLIGHT On September 8, 2012, about 1235 Pacific daylight time (PDT), an experimental Edward R. Moore MXS, N21MX, departed controlled flight and impacted terrain near Borrego Valley Airport (L08), Borrego Springs, California. The pilot was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot was fatally injured; the airplane sustained substantial damage by impact forces. The local personal aerobatic flight departed L08, about 1225. Visual meteorological conditions prevailed, and no flight plan had been filed. The owner/builder of the airplane had loaned the airplane to the pilot to "try out" his airplane. The pilot did own another make and model of aerobatic airplane. Witnesses reported that during an aerobatic flight the airplane appeared to have departed controlled flight, and the pilot was observed leaving the airplane followed by his parachute deploying. The parachute did not fully deploy before the pilot impacted the ground. On scene examination and documentation was performed by investigators, and the airplane was recovered for further examination. PERSONNEL INFORMATION A review of Federal Aviation Administration (FAA) airman records revealed that the 58-year-old pilot held a commercial pilot certificate with ratings for airplane single-engine land and instrument airplane. The pilot held a third-class medical certificate issued on April 17, 2012. It had the limitations that the pilot must wear corrective lenses for near and distant vision. No personal flight records were located for the pilot. The IIC obtained the aeronautical experience listed in this report from a review of the FAA airmen medical records on file in the Airman and Medical Records Center located in Oklahoma City, Oklahoma. The pilot reported on his medical application that he had a total flight time of 4,500 hours with 50 hours logged in the last 6 months. AIRCRAFT INFORMATION The airplane was an experimental amateur built-Edward R Moore- MXS, serial number 008. A review of the airplane's logbooks revealed that the airplane had a total airframe time of 311.8 hours at the last annual condition inspection. The logbooks contained an entry for the annual condition inspection dated March 30, 2012. The engine was a Lycoming-Ly-Con, AE10-540EXP, serial number L-52636-08E. Total time recorded on the engine at the last 100-hour annual condition inspection was 311.8 hours. The builder/owner reported the total time on the airplane as 351 hours at the time of the accident. No Hobbs meter was recovered at the accident site. The airplane was completed and issued an amateur built experimental airworthiness certificate on March 11, 2009. A logbook entry dated March 11, 2009, stated that the airplane had been assembled using the kit and plans supplied by MXR Technologies. The entry was made by an Airframe & Power Plant (A&P) Mechanic who was not the builder of record of the airplane per the FAA records. On March 21, 2009, the builder of record made a logbook entry stating that the airplane had completed Phase I of the operating limitations. He also recorded that the airplane had a total time of 42.5 hours. No logbook entries were made in the logbooks for the year of 2010. On March 5, 2011, a logbook entry for an annual condition inspection was completed with a recorded total time of 225.52 hours. The last entry was on March 30, 2012, for an annual condition inspection with a total time of 311.8 hours. WRECKAGE AND IMPACT INFORMATION Investigators examined the wreckage at the accident scene. The airplane wreckage was located about 200 yards north of the Borrego Springs Airport runway 08/26. The accident site was level sandy desert terrain with sparse vegetation. The airplane was recovered and transported to storage for further examination. MEDICAL AND PATHOLOGICAL INFORMATION The San Diego County Coroner completed an autopsy of the pilot on September 10, 2012. The FAA Civil Aerospace Medical Institute (CAMI), Oklahoma City, performed toxicological testing of specimens of the pilot. Analysis of the specimens contained no findings for carbon monoxide, cyanide, and volatiles. The drug "Minoxidil" was detected in the urine, but not detected in the blood. The medication "Minoxidil" found during the pilot's toxicological testing does not cause impairment or incapacitation. TESTS AND RESEARCH Investigators examined the wreckage at Aircraft Recovery Service, Littlerock, California, on September 18, 2012. The engine was examined with no mechanical anomalies identified. A copy of the examination report is attached to the docket. The airframe was examined, and no evidence of any airframe structural failure was noted. The control systems including the push rods, bearings, rudder controls, elevator controls, and ailerons were present with no abnormalities that would have precluded normal operations. The flight control Torque Tube Assembly was examined, and all major components of the torque tube assembly were present and accounted for. Visual inspection of the torque tube assembly had witness marks that indicated that the torque tube was not engaged in the forward bearing prior to accident impact. In addition, the structure that supported the forward bearing had been constructed in an alternate manner than the other MXS airplanes by using aluminum sheet of approximately 0.040 thickness, and attaching them to the side rails using AN type hardware. Two pieces of aluminum extruded channel had been placed on either side of the forward torque tube bearing. A copy of the examination report is attached to the accident docket. The torque tube assembly was sent to the NTSB materials laboratory for examination. The complete NTSB materials laboratory factual report number 12-118, dated October 12, 2012, is attached to the accident docket. Findings in the factual report indicated that the forward and aft bearing housings were installed in reverse of the proper direction of installation, and aluminum alloy flanges were used to attach the bearing support panel to the sidewalls, which allow the panel to flex. According to representatives of MX aircraft, the aluminum flanges were inconsistent with the other MXS airplanes as built. Examination of photographs of an exemplar airplane with a reportedly proper installation of the bearing support panel showed flanges located on the aft side of the forward bearing support panel, and the flanges were made of composite material. The other 13 aircraft which were manufactured by or for MX Aircraft were built with the front bulkhead for the torque tube assembly made with a glass reinforced epoxy laminate and attached to the side rails with carbon fiber structural brackets which were bonded to the fuselage structure. The forward face of the flight control torque tube had a number of sliding contact marks, and the sides of the face were bent aft in the areas of contact. The location and shape of the contact marks were consistent with sliding contact with the aileron control stop assembly on the forward bearing support panel. The aft faces of the aileron control stop assembly also showed missing paint and evidence of contact damage. VIDEO RECORDER The accident airplane had a GoPro HD2-14 "Hero2" camera that had been mounted to the left side of the airplane, and was recovered at the accident site. The camera was submitted to the NTSB vehicle recorders laboratory for download. A copy of the On Board Image Recorder Factual Report is included in the accident docket. The specialist's factual report was dated January 25, 2013. The report identified that the camera had sustained minor damage, and the removable 32 GB SD card was intact. The video information was copied from the SD card for review. The accident video was recorded at 1280x960 resolution, at 30 frames per second. The video was 16 minutes 17.1 se