HISTORY OF FLIGHTOn August 26, 2014, about 1830 Pacific daylight time, an experimental amateur-built Sikes Loehle 5151 Mustang, N73144, was destroyed during collision with terrain and a post-crash fire following an uncontrolled descent during initial climb about 0.13 miles east of the approach end of runway 34, Chehalis-Centralia Airport (CLS), Chehalis, Washington. The pilot, who was the registered owner of the airplane and the sole occupant, sustained fatal injuries. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed for the local flight. The airplane, which was originating at the time of the accident, was being operated in accordance with 14 Code of Federal Regulations Part 91. In an interview with the National Transportation Safety Board investigator-in-charge (IIC), a witness, who was a professional pilot, reported that while driving along the airport's south perimeter road he observed the accident airplane taxi onto the grassy area, which extended south of the approach end of runway 34, and commence its takeoff roll. The witness stated that during the takeoff roll he observed the airplane bounce several times, as the terrain seemed to be uneven, and subsequently the airplane became airborne, but only after it had proceeded up on the runway surface. The witness further stated that he observed the airplane depart in an unstable climb, rocking back and forth on both its lateral and pitch axis. The witness opined that the airplane subsequently made a right 180-degree turn at an altitude of about 500 feet above ground level, and continued the unstable climb. He then observed the airplane in a right-wing- low, steep nose down attitude prior to impact with terrain, less than 1,000 feet east of the initial takeoff point. In a statement provided to the NTSB IIC, the airport manager stated that takeoffs from the grassy area that the accident pilot used were not authorized. PERSONNEL INFORMATIONThe pilot, age 66, possessed a Federal Aviation Administration (FAA) private pilot certificate for airplane single-engine land. On the pilot's most recent application for his airman medical examination, which was dated June 16, 2011, he reported 4,500 total flight hours, with 0 hours flown in the last 6 months. On his most recent examination, the Airman Medical Examiner (AME) stated "disorganized, missed an appointment the previous day and got lost coming today, 45 minutes late, unable to complete the form, poor short term memory, confabulates, suspect organic brain syndrome or Alzheimer's." Additionally the AME noted, "abnormal neurological / psychiatric disorder" and deferred issuance of a medical certificate. The FAA medical certification division subsequently denied the pilot's medical certificate. In a statement provided to the NTSB IIC by the party who sold the airplane to the accident pilot on August 8, 2014, the seller queried the accident pilot as to how long it had been since he had flown, to which the pilot chuckled, then replied, "Flying is like riding a bike. You never forget, right?" The seller stated that he also mentioned to the pilot that a tail dragger requires a little more hands on during takeoff and landing, to which the accident pilot replied that he received his pilot's license in a tail dragger. The seller then mentioned to the accident pilot that after he returned home he should go up with an instructor to get a refresher, and to make sure that he still had good hand-eye coordination, to which the accident pilot stated, "The Mustang was an ultralight, right." The seller responded, "No. It is an experimental plane, and requires a minimum of a light sport rating to fly," to which the accident pilot replied, "Well, well, I got a private pilot's license, so it don't matter." The seller opined that after the airplane was loaded, he asked the brother of the accident pilot what his brother's intention and capabilities were. The brother replied that the airplane was his brother's dream to fly, that he had thousands of hours, and that he was going to fly it. AIRCRAFT INFORMATIONThe accident airplane, N73144, a 2007 Thomas C Sikes Loehle 5151 Mustang, serial number 5151-150968705, was a low-wing, conventional fixed gear, single-passenger, amateur-built airplane, made primarily of wood construction. The airplane was powered by a 64 horsepower Rotax 582 DCDl engine, serial number 4317429, and equipped with a 4-bladed Warp Drive Carbon Fiber propeller. According to maintenance records recovered at the pilot's hangar, the most recent inspection was performed on August 3, 2014, at a total engine time of 8.0 hours. The airplane's airworthiness certificate was dated December 6, 2007. METEOROLOGICAL INFORMATIONAt 1835, the weather reporting facility located at the Chehalis-Centralia Airport (CLS), reported wind 320° degrees at 6 knots, gusts 11 knots, sky clear, temperature 31° C, dew point 16° C, and an altimeter reading of 29.95 inches of mercury. AIRPORT INFORMATIONThe accident airplane, N73144, a 2007 Thomas C Sikes Loehle 5151 Mustang, serial number 5151-150968705, was a low-wing, conventional fixed gear, single-passenger, amateur-built airplane, made primarily of wood construction. The airplane was powered by a 64 horsepower Rotax 582 DCDl engine, serial number 4317429, and equipped with a 4-bladed Warp Drive Carbon Fiber propeller. According to maintenance records recovered at the pilot's hangar, the most recent inspection was performed on August 3, 2014, at a total engine time of 8.0 hours. The airplane's airworthiness certificate was dated December 6, 2007. WRECKAGE AND IMPACT INFORMATIONThe airplane came to rest inside of a fenced in yard of a local auto body repair business between two pickup trucks, which was about 800 feet northeast of where the pilot had commenced the takeoff roll. The airplane was destroyed by impact forces and fire damage. The destruction of the airplane was so complete, that first responders were not initially able to identify it as an airplane. The severity of the impact forces and thermal damage to the airframe's wooden structure, as well as to its engine, precluded a detailed examination of the airplane. Pieces of the airplane had impacted the south side of the auto body repair facilities' south structure, which was about 80 feet north of the main wreckage impact site. Additionally, remnants of the airplane were observed about 125 feet east, and about 75 feet southeast of the main wreckage. The largest identifiable piece of wreckage was that of the right main landing gear, which was located about 20 feet south of the main wreckage. MEDICAL AND PATHOLOGICAL INFORMATIONOn August 28, 2014, an autopsy on the pilot was performed at the Lewis County Coroner's Office, Chehalis, Washington. The cause of death was noted to be the result of blunt force injuries to the head, with arteriosclerotic and hypertensive cardiovascular disease as contributing factors. Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated no ethanol detected in Urine, no carbon monoxide detected in Blood, testing for cyanide not performed, and that testing for drugs revealed the following: 7-Amino-clonazepam detected in Blood and Urine Amlodipine detected in Liver and Blood Atorvastatin detected in Liver and Blood Quetiapine detected in Urine and Blood Salicylate detected in Urine Terazosin detected in Liver and Blood In a review of the accident pilot's FAA medical records, an NTSB medical officer reported the following: During the pilot's most recent airman medical examination on June 16, 2011, the Airman Medical Examiner (AME) stated the pilot was "disorganized, missed an appointment the previous day and got lost coming today, 45 minutes late, unable to complete the form, poor short term memory, confabulates, suspect organic brain syndrome or Alzheimer's." Additionally the AME noted, "abnormal neurological / psychiatric disorder" and deferred issuance of a medical certificate. The FAA medical certification division subsequently denied the pilot's medical certificate. The NTSB medical officer further reported that a review of the accident pilot's personal medical records revealed the following: The pilot's medical conditions included high blood pressure treated with amlodipine, hydrochlorothiazide, and lisinopril, and chronic hepatitis C. According to his most recent psychiatric note, dated April 8, 2014 (two months before the accident), the pilot carried the diagnosis of post-traumatic stress disorder (PTSD) treated with quetiapine and clonazepam. PTSD is a disorder that develops in some people who have seen or lived through an upsetting event. They may relive the traumatic event, experience excess arousal to stimulus, and avoid situations that cause symptoms. During his most recent psychiatric evaluation, the pilot was described as having a normal mood, no hallucinations, delusions or obsessions, and no thoughts of homicide or suicide. The provider noted the pilot appeared to be managing his mood with current medications. Records from January 2012 contain the diagnosis of bipolar disorder, and describe symptoms including mood swings and psychosis (having false beliefs about what is taking place or who one is and is often associated with hearing voices) treated with quetiapine. Both post-traumatic stress disorder (PTSD) and bipolar disease are associated with fluctuations in the degree of symptoms at any point in time.