WPR15LA265

The commercial pilot was conducting a personal flight. He reported that he did not recall what happened the day of the accident. One witness, who was former pilot, reported that he saw the airplane fly over his house and that the engines sounded as if they were "out of sync." A second witness, who lived about 5 miles away from the airport, reported that she saw the airplane flying unusually low. She added that the engines sounded terrible and that they were "popping and banging." A third witness, who was holding short of the runway waiting to take off, reported that he saw the airplane approaching the runway about 75 ft above ground level (agl). He then saw the airplane descend to about 50 ft agl and then climb back to about 75 ft agl, at which point the airplane made a hard, right turn and then impacted terrain. Although a postaccident examination of both engines revealed no evidence of a mechanical failure or malfunction that would have precluded normal operation, the witnesses' described what appeared to be an engine problem. It is likely that one or both of the engines was experiencing some kind of problem and that the pilot subsequently lost airplane control. The pilot reported in a written statement several months after the accident that, when he moved the left rudder pedal back and forth multiple times after the accident, neither the torque tubes nor the rudder would move, that he found several of the rivets sheared from the left pedal, and that he believed the rudder had failed. However, postaccident examination of the fractured rivets showed that they exhibited deformation patterns consistent with overstress shearing that occurred during the accident sequence. No preimpact anomalies with the rudder were found.

The seven seat, high wing, retractable-gear airplane, serial number 680E-721-28, was manufactured in 1959. It was powered by two Lycoming GSO-480-B1A6 engines, and equipped with Hartzell Propeller controllable pitch propellers. Review of copies of maintenance logbook records showed an annual inspection was completed on October 10, 2014 at a recorded tachometer reading of 784 hours, with 487 hours since left engine major overhaul, and 412 hours since right engine major overhaul. On September 21, 2015 about 1620 mountain daylight time, an Aero Commander 680-E, N222JS, impacted terrain while attempting to land at the Boise Air Terminal/Gowen Field (BOI), Boise, Idaho. The commercial pilot, sole occupant, sustained serious injuries and the airplane sustained substantial damage. The airplane was registered to, and operated by, the pilot as a 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Weiser Municipal Airport (S87), Weiser, Idaho at an unknown time. The pilot initially reported that he did not recall what happened the day of the accident. However, in a written statement provided several months after the accident, he reported that, after the accident, while disassembling the airplane, he moved the left rudder pedal back and forth multiple times, neither the torque tubes nor the rudder would move and that he believed the rudder had failed. Several of the rivets were sheared from the left pedal. Postaccident examination of the fractured rivets showed that they exhibited deformation patterns consistent with overstress shearing. One witness reported he observed the airplane fly over his house, he mentioned that the engines sounded as if they were out of sync. A second witness who lives about 5 miles away from the airport reported she observed the airplane flying abnormally low; the engines sounded terrible, they were popping and banging. A third witness, who was holding short of the runway waiting to takeoff, reported that they observed the airplane approaching the runway about 75 feet above the ground. They saw the airplane descend to about 50 feet, then climb back up to about 75 when the airplane suddenly made a hard right turn and impacted terrain. The pilot, age 63, held a commercial pilot certificate for airplane single- and multi-engine land, and single-engine sea, as well as an airframe and powerplant mechanic certificate issued on August 8, 2012. The pilot held a second-class medical certificate issued April 13, 2015, with the limitation that he must wear corrective lenses and possess glasses for near/intermediate vision. The pilot estimated that he had 18,000 total hours, 2,500 of which were in the airplane make and model. A postaccident examination of the airplane's engines was completed by representatives from the Federal Aviation Administration and Lycoming engines. There were no indications of preimpact anomalies with eitherengine. The left engine was still secured to the airframe, however, the propeller gearbox and assembly was found separated. All propeller blades were bent forward, and exhibited leading edge damage. The top spark plus were removed and displayed "worn out-normal" signatures when compared to the Champion Aviation Check a Plug Chart AV-27. The engine was rotated by hand; thumb compression was obtained on all cylinders and engine drive train continuity was established throughout. The right engine was still secured to the fuselage. The propeller hub and blades remained attached, and the blades were found mostly straight. One blade exhibited chordwise scratches, and a second blade had leading edge scratches, both of which were on the outboard about 10 inches of the blade. The third blade exhibited minor leading edge damage. The top spark plugs were removed and displayed "worn out-normal" signatures when compared to the Champion Aviation Check a Plug Chart AV-27. The engine was rotated by hand; thumb compression was obtained on all cylinders and engine drive train continuity was established. An onscene examination of the airplane was conducted by a Federal Aviation Administration Inspector. The first identified point of impact was in the gravel just south of taxiway "A"; gravel and scratch marks were spread across the taxiway, and slice marks were noted in the gravel just north of the taxiway. In addition, there were other disruptions in the gravel along with small fragments of the wing tips and other airframe pieces. The airplane came to rest on top of, and slightly on the other side of, a fence on the north side of the airport and taxiway "A". The airframe was heavily damaged. The inspector observed no fuel in the left and right wing fuel tanks; and due to the position of the airplane, he was unable to observe the fuel within the main fuel tank. The fuel selector for both engines were selected to the center tank. The right engine propellers were still secured to their hub, and the engine sustained minimal damage. The left engine propeller hub had separated from the engine; all three blades sustained mostly forward bending. During the recovery process, the recovery crew removed about 11-12 gallons of fuel from the center fuel tank.