NTSB Factual Report

HISTORY OF FLIGHT

On January 28, 2015, about 1100 central standard time, an experimental amateur-built Vans RV-9A airplane, N708JE, impacted Lake Texoma near Kingston, Oklahoma. The solo student pilot was fatally injured and the airplane was substantially damaged. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight departed the Durant Regional Airport (DUA), Durant, Oklahoma, at 0955.

A friend of the pilot witnessed a portion of the accident sequence. He reported that on the morning of the accident, he sent a text message to the accident pilot saying that he was going to be fishing on Lake Texoma. When he was on his fishing boat, the pilot called him to inform him that he was going to overfly the boat in the airplane. After flying over the boat, the airplane disappeared from his view and the friend moved the boat's location. Later, the airplane flew over the boat again, circled it once, and flew to the south. The witness began to move the boat to the south when he saw the airplane collide with the water and begin to sink. When the boat reached the airplane the friend and his boat passenger attempted to keep the airplane from sinking. They were unable to hold on to the airplane before it sank below the water's surface. When the pilot was not located, the witness contacted emergency services.

PERSONNEL INFORMATION

The pilot, age 51, held a combined student pilot and third class medical certificate, without limitations, issued on May 3, 2014. The pilot owned a Grumman AA-1B airplane and began instruction in that airplane on May 12, 2014, and soloed on May 26, 2014. In early July 2014, the pilot purchased the accident airplane and received flight instruction in that airplane beginning on September 29, 2014. The pilot's last instructional flight occurred on October 15, 2014, which was a cross country flight in the accident airplane from DUA to Clarence E Page Municipal Airport (RCE), Oklahoma City, Oklahoma, and back to DUA with two landings logged. The pilot's log book endorsement pages contained an entry dated September 29, 2014 for the pilot's proficiency to practice solo takeoffs and landings at DUA. It also contained an endorsement for the pilot's proficiency to practice solo takeoffs and landings at Sundance Airport (HSD), Oklahoma City, Oklahoma (118.7 nm from DUA), Pauls Valley Municipal Airport (PVJ), Pauls Valley, Oklahoma (61.7 nm from DUA), and RCE (116.5 nm from DUA), dated October 19, 2014; that date was crossed out and the date of January 16, 2015, was written above the original date. On October 19, 2014, the pilot was also endorsed to perform solo cross-country flights in an RV-9A. At the time of the accident, the pilot had 37.3 total hours, with 22.2 hours logged in the accident airplane. The pilot had received 15.6 hours of dual instruction of which 5.7 hours were accrued in an RV-9A.

AIRCRAFT INFORMATION

The two-seat, low wing, fixed gear, kit built airplane, serial number 91405, was manufactured in 2008. It was powered by a 160-horsepower, normally aspirated, Lycoming O-320-D2B engine, serial number L 5331-39 that drove a two-bladed, metal, Sensenich fixed pitch propeller. The airplane's last inspection occurred on June 24, 2014, at a total airframe time of 50 hours and a tachometer time of 505.2 hours. That inspection entry was prior to the pilot purchasing the airplane, and was the last entry in the log book.

METEOROLOGICAL INFORMATION

At 1055, an automated weather reporting facility at DUA, located 9 miles east of the accident site, reported wind from 190° at 9 knots, visibility 10 miles, a clear sky, temperature 68° Fahrenheit (F), dew point 46° F, and an altimeter setting of 30.09.

According to the chart contained in the Special Airworthiness Information Bulletin CE-09-25, Carburetor Icing Prevention, the airplane was operating in an area with the potential for serious icing at glide power.

WRECKAGE AND IMPACT INFORMATION

The airplane impacted the water and was recovered the day following the accident. According to divers from the Oklahoma Highway Patrol dive team, the airplane was intact with the exception of the left wing, which was located near the airplane wreckage. The airplane was floated to the surface through the use of airbags which resulted in distortion to the airplane wreckage. The airplane was towed to shore and removed from the water. Small portions of the airplane's engine cowl and cockpit items were located on a shoreline to the north of the impact area. All the items were collected and examined near the lake.

The left wing was impact separated at the wing root. The aileron bell crank to aileron pushrod was fractured in overload near the bell crank and the stick to aileron bell crank pushrod was impact separated at the threaded rod end just outboard of the bell crank. The remaining stick to aileron bell crank rod remained attached to the control stick. Flight control continuity was confirmed from the right aileron to the control stick and the rudder to the rudder pedals. Impact damage was consistent with the flaps in the retracted position.

The altimeter displayed 1,900 ft with 30.09 set in the Kollsmans window. The tachometer read 540.29 hours. The airspeed indicator needle was broken and unreliable. The fuel selector was found pointing to the left tank. The engine controls had separated from their cockpit area mounts but remained attached to the engine via the control cables. The carburetor heat gate cable was found separated from its actuator arm. The propeller remained attached to the engine at the propeller flange. Both blades remained straight and were relatively undamaged.

The pilot's seat was equipped with an unidentified four point restraint system which was found unlatched. The pilot's restraints displayed signatures consistent with loading on the restraint webbing by the adjustment bars. When compared to each other, the lap belt webbing displayed heavier witness marks than the shoulder restraints. No anomalies were detected with the airframe.

A Garmin GPSMap296 was located in the wreckage and shipped to the NTSB laboratories in Washington, D.C. for examination.

The wreckage was relocated to a salvage yard where an engine examination was later conducted under the auspices of the Federal Aviation Administration (FAA). Screens and filters were found clear of debris. The carburetor was impact separated at the throttle plate. Disassembly of the carburetor found hydraulic deformation of the metal floats. The carburetor heat gate cable was found separated from the carburetor heat gate actuator arm. No set screw was found in the clamp that normally retains the cable end. Engine continuity and cylinder compression was confirmed. The carburetor heat gate cable was sent to the NTSB for further examination. No further anomalies were detected with the engine.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was conducted on the pilot by Oklahoma's Office of the Chief Medical Examiner. The cause of death was due to blunt force trauma and drowning.

Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. Tests were negative for carbon monoxide and ethanol. Ibuprofen was detected in urine.

ADDITIONAL INFORMATION

GPSMap 296

Data from the GPSMap296 was obtained through a download at the NTSB laboratories. The accident flight was captured in the device's memory and its information was extracted. On the day of the accident, flight data shows the airplane departing DUA at 0955 central standard time. The airplane tracked to the northwest cruising about 900 ft above ground level (agl). When the airplane reached the northeast corner of Lake Texoma, it tracked to the southwest and descended over the lake. It descended to 77 ft agl and then flew a climbing, left turn. It circled the same area 1.5 times about 285 ft agl.

The airplane then flew to the northwest corner of Lake Texoma near Madill, Oklahoma, and then turned to the south and cruised about 500-700 feet agl. The airplane maneuvered around the lake south of Lebanon, Oklahoma between 30-100 ft agl. The airplane followed a portion of the Red River until it approached I-35 where the airplane turned back towards Lake Texoma and cruised at higher altitudes, between 160-900 ft agl.

When the airplane approached Lake Texoma, it descended below 100 ft agl and then climbed to 1,300 ft agl as it flew over land and then descended to 285 ft agl. At 1056:35, the airplane flew to the north at 330 ft agl and about 115 knots ground speed. North of a railroad bridge the airplane performed a near level left turn about 440 ft agl and 125 knots. The airplane slowed in the turn to 75 knots and began a turn to the south where the airplane descended and the ground speed decayed. The last recorded point was at 1059:59 with the airplane in a left turn at 87 knots and 94 ft agl.

Carburetor Heat Gate Cable

The cable was placed under a microscope and examined by an NTSB Structural Engineer. The wire displayed an indention about the diameter of the set screw. There was no smearing of the metal in area of the indentation.

The son of the pilot reported that several months prior to the accident, the pilot noticed that the carburetor heat was not working properly. The son thought the airplane was repaired at PVJ. No entries in the log book tracked any recent maintenance performed on the carburetor heat gate or gate cable. It could not be determined when or by whom any corrective actions may have been performed on the carburetor heat gate.

Airplane's Maneuvers Over the Water

The accident pilot was a fishing guide. He expressed his desire to use his airplane to find where fish were on the lake for his fishing guide friends. His instructor pilot warned him to only do so from a safe altitude. The witness/friend of the pilot explained that in the airplane, the accident pilot could spot flocks of birds that were eating schools of smaller fish which likely meant that larger fish were also nearby. The pilot and the friend had arranged a signal that the airplane would circle once over him and then fly towards where the pilot had spotted a potential fishing spot.

NTSB Probable Cause

The pilot’s continuation of a banked turn following the loss of engine power, which resulted in his failure to maintain adequate airspeed and the airplane exceeding its critical angle of attack and entering an accelerated stall at low altitude. Contributing to the accident was the loss of engine power due to carburetor icing as a result of the airplane's degraded carburetor heat system.