CEN17FA249

The pilot's decision to fly with his large dog in the two-seat, light sport airplane, and the dog's likely contact with the flight controls during landing, which resulted in the pilot's loss of airplane control and a subsequent aerodynamic stall when the airplane exceeded its critical angle of attack.

The commercial pilot was conducting a personal flight in the two-seat, light sport airplane with his dog in the right passenger seat. A witness, who was piloting another airplane in the traffic pattern, reported that, while he was on the downwind leg, he saw the accident airplane on final approach to the runway. The witness subsequently lost visual contact with the accident airplane as he turned his airplane onto the base leg. The witness did not see the accident airplane on the runway or taxiway after he turned onto final approach. The witness conducted a go-around and then saw the accident airplane in a cornfield adjacent to the runway. After the accident, the witness saw the pilot's dog running out of the cornfield where the airplane had crashed. Based on available ground track and engine data, the airplane crossed the runway 27 threshold at a calculated airspeed of 48 knots. About 3 seconds later, the airplane turned right away from the runway heading, and the engine speed increased to takeoff power. The airplane subsequently descended right wing down into the cornfield about 250 ft north of the runway centerline. The final calculated airspeed was about 44 knots. Although the airplane's wings-level aerodynamic stall speed with the wing flaps fully extended was 39 knots, the stall speed would have increased exponentially with the bank angle as the airplane turned right. According to the pilot's son, the pilot routinely flew with his dog, who weighed between 70 and 75 lbs. He added that the pilot had installed a homemade, removable, plywood device to prevent the right-seat passenger (or his dog) from inadvertently contacting the rudder pedals during flight. Although the device was not approved to be installed in the airplane, there was no evidence that it interfered with the full movement of either control stick or the pilot-side rudder pedals. Postaccident examination of the airplane and engine did not reveal any evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. Given the ground track and engine data, it is likely that the dog contacted the aileron and/or stabilator controls during landing, which resulted in the pilot's loss of airplane control and a subsequent aerodynamic stall at a low altitude when the airplane exceeded its critical angle of attack.

The Iowa's Office of State Medical Examiner, Ankeny, Iowa, performed an autopsy on the pilot. The cause of death was attributed to multiple blunt-force injuries sustained during the accident. Toxicological test results from the autopsy were negative for alcohol and drugs in blood, and no alcohol was detected in vitreous. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology tests on specimens obtained during the pilot's autopsy. The toxicology results were negative for carbon monoxide and all tested drugs and medications. The testing detected 19 mg/dL of ethanol in urine; however, no ethanol was detected in blood. The ethanol detected in urine was consistent with postmortem alcohol production and not from ingestion. A postaccident review of available meteorological data established that day visual meteorological conditions prevailed at the accident site. At 1555, about 8 minutes before the accident, the MXO automated surface observing system reported wind from 280° at 13 knots, 10 miles surface visibility, few clouds at 5,500 ft above ground level, temperature 24°C, dew point 13°C, and an altimeter setting of 29.98 inches of mercury. According to Federal Aviation Administration (FAA) records, the 90-year-old pilot held a commercial pilot certificate with airplane single-engine land, airplane multiengine land, and instrument airplane ratings. His last aviation medical examination was on August 14, 2014, when he was issued a third-class medical certificate with the limitation that he must wear corrective lenses. On the application for his medical certificate, the pilot reported having accumulated 7,450 hours of total flight experience, of which 30 hours were flown within the previous 6 months. The medical certificate expired on August 31, 2016; however, federal regulations only required the pilot to possess a valid driver's license to operate the light sport airplane. According to local law enforcement, the pilot had a valid Iowa driver's license. A search of FAA records showed no previous accidents, incidents, or enforcement proceedings. A comprehensive pilot logbook was not located during the investigation. An airplane use log recovered from the wreckage was used to calculate the pilot's recent flight experience. According to the airplane use log, he had flown 40.9, 16.8, 10.6, and 5.4 hours during the 1 year, 6 months, 90 days, and 30 days before the accident, respectively. The accident flight was about 57 minutes and was the only flight conducted within 24 hours of the accident. The two-seat light sport airplane, serial number 06-01-09, manufactured in 2006, was a high-wing monoplane constructed of primarily carbon-fiber reinforced plastic. The airplane was powered by a 100-horsepower, 4-cylinder, Rotax 912 ULS reciprocating engine, serial number 5.645.807. The engine provided thrust through a fixed-pitch, three-blade, Neuform model CR3-65-47-101.6 propeller. The airplane was equipped with fixed-tricycle landing gear, wing flaps, and had a maximum gross weight of 1,323 pounds. The FAA issued the light sport airplane a special airworthiness certificate and associated operating limitations on March 29, 2006. The airplane's hour meter indicated 664.25 hours at the accident site. At the time of the accident, the airframe, engine, and propeller had accumulated 664.25 total service hours. The engine had accumulated 225.25 hours since being overhauled on October 25, 2012. The last condition inspection of the airplane was completed on October 18, 2016, at 636.3 total airframe hours. Postaccident review of the maintenance records found no history of unresolved airworthiness issues. According to the airplane's Pilot's Operating Handbook, the wings-level aerodynamic stall speed with flaps retracted (0°) and flaps fully extended (40°) is 42 and 39 knots, respectively. The minimum and maximum continuous engine speed for takeoff is 4,500 and 5,500 rpm, respectively. The accident site was in a cornfield located adjacent to runway 27. All the airplane's major structural components and flight controls were accounted for at the accident site. The wreckage debris path and airplane damage were consistent with the airplane impacting the ground in a right-wing-down, nose-down pitch attitude while on a north-northeast heading. The initial point-of-impact (POI) was about 250 ft north of the runway centerline where fragments of the right wing tip were found. A propeller slash mark in the terrain and several fragments of a propeller blade were found about 24 ft northeast of the initial POI. The main wreckage, which consisted of the fuselage, left wing, empennage, and engine, was located 54 ft northeast of the initial POI. The fuselage was found inverted, and the cockpit's primary structure was heavily fragmented. The entire right wing had separated from the fuselage. The left wing remained partially attached to the fuselage. First responders reported that fuel was leaking from the left wing root. Both cockpit flight control sticks were found installed. Flight control continuity to the ailerons could not be established due to impact damage; however, all observed separations were consistent with overstress. Flight control cable continuity for the stabilizer and rudder was established. A homemade plywood device was installed on the right-side passenger floorboard to prevent a passenger from inadvertently contacting the rudder pedals during flight. The removable device used a hinged, vertical panel to block access to the rudder pedals. Although the device was not approved to be installed in the airplane, there was no evidence that it interfered with the full movement of either control stick or the pilot-side rudder pedals. The main landing gear remained attached to the lower fuselage. The nose landing gear remained attached to the forward fuselage. The electronic flap control selector was found in the flaps fully extended (40°) position. The ignition switch was found selected to BOTH. The fuel valve control assembly was damaged during impact. The throttle control was found full forward. The engine choke control was found in an intermediate position. The brake control was found selected to OFF. The ballistic-recovery parachute handle was not pulled, and the safety pin was found installed. The activation cable to the rocket motor was cut before the wreckage was moved to prevent an inadvertent discharge. The engine remained attached to the firewall, and the propeller hub remained attached to the crankshaft flange and spacer. The three-blade propeller exhibited blade damage consistent with rotation at impact. Two of the three propeller blades separated about 6 inches from the hub. The remaining propeller blade remained attached to the hub, but the outboard quarter of the blade had separated during impact. Several propeller fragments were located along the wreckage debris path. The engine did not exhibit any crankcase or cylinder fractures. No oil leaks were observed on the exterior engine components. The oil reservoir contained engine oil and no metallic debris. A partial disassembly of the mechanical oil pump did not reveal any anomalies. The sparkplugs exhibited features consistent with normal engine operation. Both carburetors remained attached to their respective induction tubes. The right carburetor contained residual fuel. The left carburetor contained no fuel. No contamination was observed in the carburetor bowls or their fuel screens. Internal engine and valve train continuity were confirmed as the crankshaft was rotated. Compression and suction were noted on all cylinders when the crankshaft was turned. The dual electronic ignition system appeared undamaged. Postaccident examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. On July 1, 2017, at 1603 central daylight time, a Flight Design CTSW light sp