Aviation Accident Summaries

Aviation Accident Summary IAD04LA048

Bayport, NY, USA

Aircraft #1

N57003

Boeing A75N (PT17)

Analysis

The pilot took off with an approximately 10-knot, right quartering tailwind. Shortly after lift off, about 300 feet, the engine, which had been at full power, lost 300-400 rpm. The airplane then veered to the left, stuck a tree and a telephone pole, then the roof of a house before coming to rest inverted in the front yard. Subsequent examination of the airplane revealed that the engine's right magneto would not produce spark.

Factual Information

On September 22, 2004, about 1615 eastern daylight time, a Boeing A75N (PT-17), N57003, was substantially damaged when it impacted a house, shortly after takeoff from Bayport Aerodrome (23N), Bayport, New York. The certificated airline transport pilot and the pilot-rated passenger received minor injuries. Visual meteorological conditions prevailed, and no flight plan had been filed for local personal flight, conducted under 14 CFR Part 91. According to the pilot's written statement, he performed a magneto check and a flight control check, which were "OK". He then taxied back the full length of runway 18, and noted that the winds were from the southwest at "12, 15." During the takeoff, the pilot applied full throttle, "full power was there," and "acceleration [was] normal." The airplane lifted off the runway at 60 mph, and had climbed to 300 feet, when the engine began to lose power, about 300-400 rpm. The pilot was unable to return to the runway, so he tried to land in a schoolyard, but was unable. The pilot-rated passenger, who was also a certificated airline transport pilot, wrote a statement that was almost the same as the pilot. He too reported that the winds from the windsock appeared to be from the southwest at 12-15 mph. A witness, also a certificated airline transport pilot, and an airframe and powerplant mechanic, reported that he was preflighting his airplane, when he noticed a red and white Stearman taking off to the south. He said to his friend, "what the heck is he doing, look at that windsock, it's sticking out straight from the northwest." The witness continued to watch the airplane "lumber into ground effect with an abnormally nose high attitude. The airplane was paralleling the tree line and never escaped ground effect." The airplane then crossed a tree line on the east side of the airport, "missing the trees by not more than a few feet." In addition, "the engine was generating full, uninterrupted power crossing the tree line." Then there was a sound of the "engine stopping, backfiring and impact noise all in rapid succession." The witness also commented that the backfire sound he heard was normal for a radial engine, when it was "intentionally throttled back or shut down." According to a Federal Aviation Administration (FAA) inspector, the airplane descended just east of the airport, hit a tree, then a telephone pole and the roof of a house before coming to rest inverted in the front yard. During a subsequent examination, over 30 gallons of fuel was siphoned from the airplane, and a fuel sample revealed no presence of water. The oil screen, carburetor and fuel lines were clean, and the engine was intact. The front seven engine spark plugs were removed, and compression was confirmed on all cylinders. The remaining seven spark plugs were then removed, and all spark plugs were inspected, with no anomalies noted. The spark plug harness was also examined, with no sign of chafing or broken contacts. Continuity was also confirmed between the engine and throttle controls, and the "carburetor heat was operational." The magnetos were tested for spark while still on the engine. The left magneto produced spark, while the right magneto did not. The magnetos were then removed, and transported to a repair station for testing. Neither magneto produced spark; however, the repair station did not have the proper distributor blocks for the magnetos, and it could not be determined if the grounds were removed. The FAA inspector also contacted the engine manufacturer, where a representative stated that if one of the magnetos had failed, there would be a drop of approximately 300-400 rpm. Winds, recorded at an airport 8 nautical miles to the north, at 1556, were from 310 degrees true, at 10 knots. Winds, recorded at 1656, were from 300 degrees true at 10 knots. Temperature and dew point for both observations were 81 degrees F and 53 degrees F respectively. Density altitude was calculated to be about 1,400 feet.

Probable Cause and Findings

The failure of a magneto, which resulted in a loss of engine power. Factors in the accident were the pilot's decision to take off downwind, which resulted in reduced airplane performance, and the tail wind.

 

Source: NTSB Aviation Accident Database

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