History of Flight
On May 17, 2016, about 1842 mountain standard time, a North American AT-6, N3198G, was destroyed when it impacted terrain shortly after departing Falcon Field Airport (FFZ), Mesa, Arizona. The airline transport pilot and passenger sustained fatal injuries. The airplane was registered to Wings of Flight Foundation and operated by the pilot as a 14 Code of Federal Regulations Part 91 air tour flight. Visual meteorological conditions prevailed and no flight plan was filed for the local flight, which originated from FFZ about 1840.
Company personnel reported the accident airplane was in trail behind another company airplane of the same make. The flight’s purpose was to tour the area north of the airport before returning. Witnesses at the airport saw the airplane depart runway 22L and heard the engine producing popping sounds followed by a loud bang. One witness stated the engine seemed to be producing little or no power. Witnesses further reported the airplane turning right and slowing down. The airplane subsequently struck the ground and a postcrash fire ensued.
Review of recorded radio transmissions from the FFZ air traffic control tower revealed that about 2 minutes after the flight of two was cleared for takeoff, the accident pilot transmitted "Dash 2 Mayday." The pilot did not state the nature of the emergency.
Personnel Information
The pilot, age 43, held an airline transport pilot certificate with airplane single-engine land and multi-engine land ratings. He was issued a first-class FAA medical certificate on July 22, 2015, with no limitations. On the application, he reported 11,950 total flight hours, with 465 hours in the previous six months. His digital logbook from January 1, 2013, through April 24, 2016, showed a total of 2,744.1 flight hours during that period. He had about 50 hours of flight experience in the accident airplane make and model, including about 11 hours in the accident airplane.
Aircraft Information
The two-seat, single-engine, low-wing, retractable landing gear airplane, serial number 84-7721, was manufactured in 1942. It was powered by a Pratt & Whitney R1340-AN, 550-hp reciprocating engine, serial number 2D700, driving a Hamilton Standard two-bladed controllable pitch propeller. The most recent annual inspection was completed February 13, 2016, at a total aircraft time of 8,746.9 hours.
Meteorological Information
The nearest automated weather report from Phoenix-Mesa Gateway Airport (IWA), 10 miles south, at 1859 included wind from 290° at 9 knots, 20 statute miles visibility, scattered clouds at 12,000 ft agl, ceiling broken at 15,000 ft, temperature 29°C, dew point 4°C, and altimeter 29.77 inHg. The 1851 observation at Sky Harbor International Airport (PHX), 14 miles away, included wind from 310° at 26 knots gusting to 37 knots, 9 miles visibility, scattered clouds at 2,100 ft and 11,000 ft, ceiling broken at 21,000 ft and 25,000 ft, temperature 27°C, dew point 6°C, and altimeter 29.75 inHg. A peak wind of 320° at 37 knots was recorded at 1844.
Wreckage and Impact
The accident site was about 1,400 ft from the departure end of runway 22L. The airplane impacted terrain and came to rest on a road on a heading about 37° magnetic. All major structural components were within the debris path, oriented about 12° magnetic and about 380 ft long. The first identified point of contact (FIPC) was a 15-ft-tall orange tree. About 20 ft beyond was a section of disturbed ground, 12 ft long and 1 ft wide, consistent with a wing strike. The left wing separated and was inverted; its tank exhibited impact signatures. The left aileron and wing tip were found east of the debris field. About 100 ft southwest was the separated oil cooler with impact damage surrounded by an oil pool.
The main wreckage, about 170 ft from the FIPC, consisted of fuselage, empennage, right wing, and engine. The right wing remained attached by one control cable and was upright on a heading of 120°, mostly consumed by postimpact fire. The fuselage rested on its left side on a heading of 310°, with thermal damage to the lower and left side revealing internal structure. The instrument panels had minor damage; the pilot’s seatbelt buckle was secured and thermally damaged; the passenger seat restraint was not located. The engine separated from the airframe with impact damage to the propeller assembly. The oil sump remained attached and was leaking oil. The empennage exhibited thermal and impact damage and rested on its right side. A separated propeller blade tip was found about 210 ft from the FIPC.
The forward crew station instrument panel top portion was mostly intact; the bottom portion (switches, breakers, radios) had thermal damage. The throttle, mixture, and propeller quadrant separated with linkages intact, disconnected from the aft seat controls, consistent with impact. The aft crew station instrument panel had thermal damage and instruments were charred and unreadable. Both canopies were found open. The fuel selector handle in the forward crew station rotated freely and its position at impact could not be determined. The aft station handle was detached. Both fuel selectors were placarded "Left," "Right," and "Off." The fuel selector valve was separated and disassembled; its position was consistent with the reserve fuel port, which was capped with a blanking cap. Both left and right fuel line ports contained melted nylon from the selector cone.
Flight control cable continuity was confirmed from each cockpit to the associated surface through tension overload separations or cuts made during recovery.
All engine accessories remained attached except the generator and hydraulic pump. Forward spark plugs exhibited normal operational signatures. The propeller was manually rotated and rotational continuity was established throughout the engine to the rear accessory case. Thumb compression and suction were obtained on all cylinders except the No. 6 cylinder, which had impact damage. The carburetor disassembly showed both floats intact and undamaged; the needle valve was intact; no debris was noted on the fuel screen or in the float bowl.
The propeller remained attached to the crankshaft flange; both blades were secure in the hub; counterweights were intact and undamaged. One blade exhibited S-bending with leading edge gouging and chordwise striations on the forward side. The opposing blade was curled aft from about midspan, with the outboard tip separated; its forward side had chordwise striations.
The engine-driven fuel pump was removed and examined; the drive shaft rotated freely by hand. When the fuel inlet line was submerged in water and the pump actuated, water flowed through and expelled from the outlet line.
Both magnetos were removed and successfully bench tested on August 8, 2016, at Precision Engines LLC., Everett, WA.
No evidence of any preexisting mechanical malfunction was found that would have precluded normal operation of the airframe or engine.
Additional Information
Aircraft maintenance records indicated the airplane was completed by North American Aviation on December 15, 1942, under Type Certificate A-2-575, and shipped directly to the South African Air Force (SAAF). It was originally equipped with left- and right-wing fuel tanks and a reserve tank within the left tank. The SAAF modified the fuel system per supplemental type certificate (STC) SA00636CH, allowing fuel in the right tank to flow directly to the left tank (from which the reserve tank had been removed) through an interconnecting fuel pipe, then from the left tank through an ON/OFF valve to the engine, making fuel tank selection unnecessary.
No maintenance records existed for 1989–1995. In 1996, the airplane returned to the United States. On April 11, 1997, it received a Special Airworthiness Certificate in the experimental category; on May 3, 1997, a Standard Airworthiness Certificate was issued, indicating conformance to TCDS A-2-575 Revision 13. However, a postaccident review showed that, based on its serial number, the airplane was not eligible for standard type certification.
The airplane’s fuel system was reconfigured at an unknown time; no maintenance records documented the modification. Postaccident examination showed the interconnecting fuel pipe between the left and right tanks had been removed and the reserve port on the fuel selector valve was capped. The left fuel tank reserve port stand pipe was also removed. The fuel selector valve face displayed quadrants for Left, Right, and Off, and a blank quadrant where the Reserve position had been located. Although the Reserve position was not marked, the selector could still be moved to that position, resulting in a loss of fuel flow to the engine because that port was capped. During the wreckage examination, the fuel selector valve was found in a position consistent with the Reserve position; however, its position at the time of the accident could not be determined.
In an interview with an FAA inspector, the operator stated the fuel selector was made of cork and excessive manipulation could cause damage or internal wear. The selector was rarely moved and normally stayed on the left tank position because most flights were short and did not require both tanks. It would only be moved during longer flights or if the pilot perceived a fuel issue. The operator indicated the last flight before the accident was on the weekend of April 12, 2016, from FFZ to Phoenix-Mesa Gateway Airport (IWA) and back, about 20 minutes each way. The airplane was topped off at IWA. The accident flight was the second flight of the day; the first lasted about 30 minutes or less. The FAA inspector estimated the airplane had flown about 50 minutes to an hour since being refueled on the left tank. When asked about leaning procedures, the operator stated they leaned very little on most flights (20–30 minutes) but would lean on longer cross-country flights or at high-altitude airports.
The FAA inspector also interviewed several T-6 pilots; common practice in case of a fuel interruption was to select the reserve position for airplanes so equipped.
Medical and Pathological Information
The Maricopa County Office of the Medical Examiner performed an autopsy of the pilot; the cause of death was multiple blunt force injuries. The FAA Bioaeronautical Sciences Research Laboratory performed toxicology testing; specimens tested negative for carbon monoxide in blood and ethanol in urine. No presence of amphetamines, opiates, marijuana, cocaine, phencyclidine, benzodiazepines, barbiturates, antidepressants, or antihistamines was detected in urine.