Aviation Accident Summaries

Aviation Accident Summary DFW06LA041

Fort Worth, TX, USA

Aircraft #1

N67195

Boeing A75N1 (PT17)

Analysis

The pilot reported that on the crosswind leg of the traffic pattern, while about 200 feet above ground level, the airplane experienced a complete loss of engine power. As the 22,300-hour ATP rated pilot, with 109-hours in make/model, was attempting to avoid obstacles, the airplane entered a spin and impacted terrain. There was no postimpact fire. The pilot reported that he had not experienced any problems with the airplane's flight controls. An examination of the engine and fuel system revealed no pre-impact anomalies. The reason for the reported loss of engine power could not be determined. Several eyewitnesses reported observing the pilot perform several touch-and-goes from Runway 14. The eyewitnesses reported that on each takeoff the airplane would climb at a steep angle of attack followed by a steep, low altitude, left turn directly to the downwind leg of the traffic pattern. The weather observation facility located 5 nautical miles northeast from the site of the accident, reported wind from 160 degrees at 7 knots.

Factual Information

On December 26, 2005, about 1728 central standard time, a single-engine Boeing A75N1 (PT17) biplane, N67195, was substantially damaged following a loss of control while maneuvering in the traffic pattern at Hicks Airfield (T67), near Fort Worth, Texas. The airline transport rated pilot sustained serious injuries and the sole passenger was fatally injured. The vintage airplane was registered to a private corporation and operated by the pilot. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The local flight originated from T67 about 1705. According to the pilot, he had been in the traffic pattern performing touch-and-go landings to Runway 14. On the pilot's fifth takeoff of the day he climbed approximately 125 feet above ground level (agl) before turning left to the crosswind leg of the traffic pattern. The pilot reported that while climbing through 200 feet agl he heard a "loud bang and backfire" followed by a complete loss of engine power. The pilot added that he lowered the airplane's nose and initiated a turn into the wind. While the pilot was attempting to avoid obstacles the airplane entered a "spiral" and impacted terrain. The pilot further reported that he had not experienced any problems with the airplane's flight controls. A commercial pilot, who was near the airport fuel pumps at the time of the accident, reported observing the airplane flying in the traffic pattern. The eyewitness reported that the airplane was in the pattern "doing low passes over the runway." At the conclusion of each pass the airplane would ascend almost vertical before "banking very steep" to the left. On the final pass, while "banking", the airplane entered a spin and descended out of sight behind a hangar. Another pilot witness reported observing the pilot perform an engine run up, depart on Runway 14, and perform several touch-and-goes. "Upon climb out, I noticed the Stearman was at a very steep climb angle, then it turned sharply to the left at what I figure to be about 100 feet AGL. It disappeared below the south hangars' roofs, which seemed unusually low, as I had seen other airplanes at a higher altitude and much more visible in the pattern." The witness further reported, "we watched it continue to pull up sharply upon [each] takeoff and drop the nose to regain airspeed then immediately turn sharply and steeply to the left several more times." A third eyewitness, who reported serving twenty years as a Naval Aviator beginning in 1948, reported observing the airplane climbing steeply after takeoff. "The angle was so extreme that I could see it losing airspeed as it climbed. I was concerned that he was nearing a stall. At what seemed to be the last possible moment before a stall, [the pilot] nosed over sharply to level flight, regained some speed, and made a fairly tight turn to the downwind leg of the pattern. His pattern was close to the runway, and lower than normal. I would estimate it at 500 feet." The eyewitness further stated that the pilot performed a wheel landing and "could see that he was holding the airplane on the runway well beyond normal flying speed." It appeared as if the pilot was gaining extra airspeed "to allow him to make another spectacular zoom after takeoff, such as I had witnessed earlier." The eyewitness did not see the accident occur. According to a fourth witness, "on lift off [the] engine backfired twice and lost power. [The] aircraft went into a left spiral and impacted [the] ground nose first." Inspectors from the Federal Aviation Administration conducted the on-site documentation of the wreckage. The airplane came to rest upright in a grassy field approximately 1,209 feet southeast of the departure end of Runway 14. The Global Positioning System (GPS) coordinates recorded at the accident site were 32 degrees 55.502 minutes North latitude and 097 degrees 24.359 minutes West longitude, at a field elevation of approximately 850 feet mean sea level (msl). There was no postimpact fire and all major components of the airplane were accounted for at the site. The airplane was recovered to Air Salvage of Dallas (ASOD) for further examination. An investigator for the National Transportation Safety Board examined the engine at ASOD. Due to impact damage the engine could not be rotated and a partial teardown examination was performed. The crankcase front main section was fractured during impact and allowed for a visual inspection of the forward crankshaft ball bearings. The ball bearings were silver in color and did not exhibit galling or thermal discoloration. All pistons and connecting rods remained attached to the crankshaft and did not appear to be damaged. The rear accessory case was removed and gear continuity was established. Oil was present on the accessory gears and no missing teeth or preimpact anomalies were noted. A borescope examination of the cylinders and valves revealed no anomalies. The oil pressure and scavenge pump turned freely when rotated by hand. When disassembled, all oil impellors were present with no gouges or unusual wear in the cavity walls. The carburetor was disassembled and examined with no anomalies noted. Both magnetos produced spark when rotated by hand. Both oil screens were found unobstructed and absent from debris. The oil filter was cut open and the element was found absent of visible metal particles. The reason for the reported loss of engine power could not be determined. The propeller remained attached to the crankshaft. One blade was found straight with longitudinal cracks and an indentation near the tip. The other blade was pushed aft slightly and had several cracks from the hub extending to the tip. Neither blade exhibited chordwise scratches or leading edge gouging. According to the pilot, the airplane contained approximately 45 gallons of 100 Low Lead aviation fuel at the time of departure. One of the first responders to the accident reported observing fuel spilling out from the wing as he approached the airplane. The fuel cap was found attached and the fuel tank vent was found unobstructed. The 1940-model Boeing A75N1 (PT17), serial number 75-1755, was a bi-wing, tube, fabric, and wood airplane, with a fixed conventional landing gear, and was configured for two occupants. The airplane was powered by a direct drive, carbureted, air-cooled, normally aspirated, seven-cylinder radial engine. The engine was a Continental W-670-6A, serial number 26704, rated at 220 horsepower, and was driving a two-bladed fixed pitch wooden Sensenich propeller. According to the airframe and engine logbooks, the airplane's most recent annual inspection was completed on May 23, 2005. At that time the airframe total time was recorded as 2,091 hours and the engine had accumulated approximately 291 hours since major overhaul. Hicks Airfield was a non-controlled airport operating under class G classification airspace. The field elevation was 855 feet mean sea level (msl). Runway 14 was a 3,740-foot-long by 60-foot-wide asphalt runway. At 1753, the weather observation facility at Fort Worth Alliance Airport (AFW), near Fort Worth, Texas, located 5 nautical miles northeast from the site of the accident, reported wind from 160 degrees at 7 knots, visibility 10 statute miles, clear of clouds, temperature 68 degrees Fahrenheit, dew point 28 degrees Fahrenheit, and barometric pressure setting of 29.80 inches of Mercury.

Probable Cause and Findings

The pilot's failure to maintain airspeed, which resulted in an inadvertent stall/spin. Contributing factors were the reported loss of engine power for undetermined reasons and the low altitude maneuver.

 

Source: NTSB Aviation Accident Database

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