ERA15FA102

The pilot's failure to maintain control while maneuvering at low altitude, which led to the airplane exceeding its critical angle-of-attack and experiencing an aerodynamic stall.

Several witnesses observed the airplane during engine start and reported that, when the engine started, the airplane tipped forward onto its nose and then fell back and its tail struck the ground. The pilot exited the airplane, walked to the back, returned to the cockpit, and then taxied out. No witnesses reported seeing the pilot examine the underside of the tail or the elevators after the tail strike. A video recording made by one of the witnesses after the tail strike showed that the airplane departed, climbed to about 300 feet above ground level (agl), made a 180-degree left turn, and performed a pass down the runway in the opposite direction of the takeoff. A few seconds later, after executing another 180-degree turn, the airplane performed another low pass down the runway, this time in the direction of the takeoff. The airplane then entered a left turn, the bank angle increased until the wings were almost perpendicular to the ground, the nose of the airplane dropped, and the airplane descended in a nose-down attitude to ground impact. The airplane came to rest on its nose with the fuselage nearly perpendicular to the ground. Postaccident examination revealed that the elevator trim cable was separated from the trim tab. Although it is possible the trim cable disconnected when the tail struck the ground during engine start (and would have been noticeable to the pilot if he had looked), the investigation could not conclusively determine when the trim cable separated or whether the separation contributed to the pilot's loss of airplane control. No other mechanical malfunctions or abnormalities were noted that would have precluded normal operation. It is likely that, during the low altitude flyby, the pilot inadvertently entered an aerodynamic stall while maneuvering and did not have sufficient altitude to recover.

HISTORY OF FLIGHT On January 16, 2015, about 1100 eastern standard time, an experimental, amateur-built Aventura II, N511DS, was substantially damaged when it impacted terrain at the Sebring Regional Airport (SEF), Sebring, Florida. Visual meteorological conditions prevailed and no flight plan was filed for the local demonstration flight. The sport pilot and student pilot-rated passenger were fatally injured. The airplane was owned by a private individual and was operated by Aero Adventure for the demonstration flight, conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The flight departed at 1055. According to local authorities, several eyewitness observed the airplane, during startup on the ramp, strike the tail of the aircraft on the concrete ramp area. A witness further reported that the pilot exited the airplane, walked to the back of the aircraft, returned to the cockpit, started the engine, and then taxied out for takeoff. No witnesses reported seeing the pilot look on the underside of the elevator or the tail of the airplane after the tail strike. According to a video taken by an eyewitness, the airplane was observed departing, climbing to about 300 feet above ground level (agl), performing a left turn, and then conducting a pass down the runway in the opposite direction. The video then shows the airplane performing a second pass, about 300 feet agl, down the length of the runway and then performing a left turn. The airplane was then observed continuing the left bank until the wings were nearly perpendicular to the ground, the nose of the airplane dropped, and the airplane was last seen in a nose down attitude descending behind the fuel tanks at the airport. According to contract air traffic control personnel, the airplane departed, flew the traffic pattern, then flew a "low approach," climbed to about 300 feet agl, made a left turn, and then impacted the ground nose first. PERSONNEL INFORMATION According to Federal Aviation Administration (FAA) records, the pilot held a sport pilot certificate issued October 8, 2010. He did not hold, nor was he required to hold, any class medical certificate while flying a light sport aircraft. He was medically eligible to fly as a light sport pilot as long as he had a valid driver's license. At the time of this writing no record of flight hours were located. According to FAA records, the student pilot-rated passenger was issued a second-class medical certificate on February 27, 2008. On the most recent medical application the pilot reported 11 total flight hours. Although the medical certificate had expired he would have been medically eligible to fly as a light sport pilot as long as he had a valid driver's license. AIRCRAFT INFORMATION According to FAA records, the airplane, serial number AA2A0124, was issued a special airworthiness certificate on September 1, 2005 and was registered to a private individual. According to documentation provided by the previous owner, a letter of agreement and contract for purchase with Aero Adventure, dated November 20, 2014, revealed that Aero Adventure would be in possession of, and held responsible for, the airplane. No bill of sale, dated prior to the accident flight, was provided to the NTSB. The airplane was powered by a Rotax 912 ULS, 100-hp engine. It was driven by an IVO 3B-GA propeller. The airplane's most recent condition inspection was conducted on November 17, 2012 with a recorded hour meter reading of 353.1, the hour meter reading found in the wreckage indicated 362.52 hours. The fuselage of the airplane consisted of a fiberglass hull with seating provisions for two occupants. Pontoons were located at the outboard portion of each wing, retractable main landing gear were attached to the fuselage, and a steerable tail wheel was attached to the empennage. The airplane was formerly equipped with a Ballistic Recovery Parachute (BRS) system; however, at some point prior to the accident, the BRS system was removed. Examination of the maintenance records did not reveal any logbook entries of the BRS system being removed nor of any recalculation of the basic operating weight and center of gravity (CG) position. Although an accurate CG could not be determined, utilizing the aircraft empty weight, located in the airframe maintenance record, dated August 30, 2005, the pilot and student pilot-rated passenger weights acquired during the autopsy, and considering a full tank of fuel. The aircraft, at the time of takeoff, would have been below the maximum allowable takeoff weight. AIRPORT INFORMATION The airport was a publically-owned airport and at the time of the accident had an operating contract control tower, due to the airshow that was taking place at the time; however, normal operations at this airport would not have utilized an operating control tower. The airport was equipped with two runways designated as runway 1/19 and 14/32. The runways were reported as "in good condition" at the time of the accident. Runway 1/19 was a 5,234-foot-long by 100-foot-wide runway and runway 14/32 was a 4,990-foot-long by 100-foot-wide. The airport was 62 feet above mean sea level. METEOROLOGICAL INFORMATION The 1059 recorded weather observation at SEF included wind recorded as calm; however, according to personnel associated with the airport the Automatic Weather Observation System was reported out of service due to the wind indicator. It also recorded broken clouds at 10,000 feet agl, 10 miles visibility, temperature 17 degrees C, dew point 13 degrees C, and barometric altimeter 30.14 inches of mercury. According to written statement by contract personnel working in the temporarily-manned tower, the wind was from 360 degrees at 13 knots. WRECKAGE AND IMPACT INFORMATION According to local authorities, eyewitness reports, and an eyewitness video recording, the airplane was performing a "fly-by" when the airplane pitched up, rolled to the left, and nosed down, impacting the ground. The airplane impacted the ground in a near vertical position. An eyewitness, who was also a mechanic, reported audibly observing the engine "cut out or reduced power" just prior to the nose down decent. Another eyewitness reported that the "tail appeared to flutter." The airplane impacted the ground just prior to the arrival end of runway 14, about 150 yards from the airport's fuel storage farm. The debris path was compact and only a single ground scar was noted where the airplane impacted and another smaller ground scar was located where the engine came to rest. The airplane exhibited various degrees of impact and crush damage. Flight control continuity was confirmed from the cockpit control to the respective flight control surface. However, the left side elevator, as viewed from behind the airplane, was noted as indicating about 15 degrees trailing edge down and the elevator trim was noted as fully deflected, trailing edge down. The right side elevator, as viewed from behind the airplane, was noted as in the neutral position. Examination of the elevator torque bar revealed the left side elevator torque bar exhibited numerous bends in both the positive direction on the forward top channel flange and in the negative direction on the aft bottom channel flange. The trim tab cable was also found separated from the cable eyelet and extensive corrosion was noted on the eyelet and cable. Several support cables exhibited tensile overload. The engine, mounted above and aft of the cabin, was separated from the airplane by local authorities, to facilitate recovery The propeller remained attached to the engine; however, two of three propeller blades were impact-separated about 5 inches from the propeller hub, and the other propeller blade exhibited some indication of rotation, slight rotational scoring, and exhibited leading edge damage. Fluid was evident throughout the engine that appeared similar in color and smell as automotive gasoli