HISTORY OF FLIGHTOn May 5, 2018, at 1002 eastern daylight time, an experimental, amateur-built Belair Raven airplane, Canadian registration C-FNKZ, impacted terrain during the initial climb after takeoff from Sault Ste. Marie Municipal Airport (ANJ), Sault Ste. Marie, Michigan. The private pilot and pilot-rated passenger were fatally injured, and the airplane was substantially damaged. The airplane was owned by the pilot who was operating it as a Title 14 Code of Federal Regulations Part 91 personal flight. Day, visual meteorological conditions prevailed for the local flight, which departed without a flight plan. According to witnesses, the airplane taxied to runway 32 and departed in a nose-high attitude. A flight instructor compared the climb to an aggressive short-field takeoff or a banner pilot's climb after picking up a banner. Witnesses noticed that, after reaching about 100 ft above ground level, the airplane turned right and transitioned to a steep nose-down spin until ground impact. The flight instructor stated that the engine noise sounded normal throughout the takeoff until ground impact. PERSONNEL INFORMATIONThe pilot, age 67, held a Canadian private pilot certificate with an airplane single-engine land rating. On February 8, 2018, the pilot was issued a Canadian Category 3 medical certificate with a requirement for glasses to be worn and a restriction of day visual only flight due to color vision deficiencies. The pilot had accumulated 505 total hours of flight experience, with 61 hours in the accident airplane. Flight reviews were not recorded in the pilot's logbook. The pilot-rated passenger, age 75, held a Canadian private pilot certificate with an airplane single-engine land rating. On January 24, 2018, the passenger was issued a Canadian Category 1 medical certificate with a requirement for glasses to be worn. The passenger frequently flew with the pilot in the accident airplane. AIRCRAFT INFORMATIONThe high-wing, tailwheel-equipped airplane was completed by the pilot in 2012 and was issued a Canadian Special Certificate of Airworthiness. The airplane was equipped with a Honda 3.5-liter engine and a Performance three-blade, fixed pitch wooden propeller. The airplane was not equipped with any stall warning devices. On the day of the accident, the airplane was lightly loaded with cargo. METEOROLOGICAL INFORMATIONAt 0955, the automated weather observation station (AWOS) at ANJ reported wind from 270° at 11 knots with gusts to 15 knots, 10 miles visibility, clear skies, temperature 12°C, dew point 3°C, and an altimeter setting of 29.93 inches of mercury. The AWOS was located about 1/4 mile east of the runway. AIRPORT INFORMATIONThe high-wing, tailwheel-equipped airplane was completed by the pilot in 2012 and was issued a Canadian Special Certificate of Airworthiness. The airplane was equipped with a Honda 3.5-liter engine and a Performance three-blade, fixed pitch wooden propeller. The airplane was not equipped with any stall warning devices. On the day of the accident, the airplane was lightly loaded with cargo. WRECKAGE AND IMPACT INFORMATIONExamination at the accident site revealed that the airplane impacted terrain and came to rest in a near-vertical, nose-down attitude on a heading about 201° about 180 ft east of runway 32. Both wings were crushed aft and remained attached to the fuselage. The fixed main landing gear assemblies were attached to the fuselage and the flight control surfaces remained attached to their respective airframe surfaces; elevator control, elevator trim, and rudder control continuity was established to the cockpit area. Aileron control continuity was established from both ailerons to the cockpit. The left aileron cable, which was slack, was disengaged from its respective bellcrank. All three multilaminate wood propeller blades were fractured near the hub. The propeller remained attached to the engine and the spinner was crushed aft. The engine was rotated by hand from the front crankshaft. Thumb suction and compression was observed at all cylinders with normal valve train and crankshaft continuity. Spark plug electrodes exhibited normal wear signatures. Witness marks on the seat rails indicated that both pilot and passenger seats were in a normal position during ground impact. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. ADDITIONAL INFORMATIONAccording to the flight instructor who witnessed the accident, during departures from runway 32 with westerly winds present, he would often notice turbulence and swirling air. He attributed this effect to the tall trees located about 100 yards west of the runway. MEDICAL AND PATHOLOGICAL INFORMATIONThe Chippewa County Medical Examiner, Sault Ste. Marie, Michigan, conducted autopsies of the pilot and passenger and determined that the cause of their deaths was due to blunt force injuries. The pilot's autopsy revealed left ventricular hypertrophy, a thickening of the wall of the left ventricle. The coronary arteries were free from atherosclerosis. An area of scar in the subepicardial area of the anterior wall of the left ventricle as well as some fibrosis in the lateral and posterior walls were identified with microscopy. The remainder of the cardiac examination was unremarkable. The pilot's wife stated that the pilot had experienced chest pains about 3 years before the accident, but she was not aware of any recent significant health issues. The passenger's autopsy revealed evidence of bilateral corneal transplants and emphysema. An area of 70-80% stenosis was identified in the left anterior descending coronary artery and there was some evidence of perivascular fibrosis on the microscopic examination in the anterior and lateral walls, as well as the left side of the septum. The passenger's son stated that, during the 2 years before the accident, his father would get tired more easily during walks and while climbing stairs. The Federal Aviation Administration Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, conducted toxicological testing on specimens from the pilot and passenger. The results were negative for all tests conducted.