Aviation Accident Summaries

Aviation Accident Summary NYC06LA097

Avondale, PA, USA

Aircraft #1

N15507

Piper PA-28-140

Analysis

During the initial climb, about 1,500 feet, there was a loud metallic-sounding explosion; oil sprayed onto the windscreen, the engine cowling opened, and a section of the propeller departed the airplane. The pilot maneuvered the airplane toward an open area bordered by trees, but the airplane struck the trees, burst into flames, and then collided with terrain. Examination of the propeller revealed that a large portion of the fracture surface displayed crack arrest positions typical of fatigue cracking. The fracture features emanated from an origin area on the camber (forward) surface of the propeller. Microscopic examination revealed an area of corrosion around the fatigue origin, as well as sanding scratches and conversion (Alodine) coating. Examination of maintenance records revealed repairs to the face of the propeller blades, as well as "repitching" of the propeller blades following the overhaul and conversion of the engine.

Factual Information

On April 16, 2006, at 1318 eastern daylight time, a Piper PA-28-140, N15507, was destroyed during a forced landing following a loss of engine power near Avondale, Pennsylvania. The certificated private pilot was fatally injured, and the passenger was seriously injured. Visual meteorological conditions prevailed for the local personal flight that departed New Garden Airport (N57), Toughkenemon, Pennsylvania, about 1315. No flight plan was filed for the flight conducted under 14 CFR Part 91. In a telephone interview, the passenger stated that he and the pilot performed the preflight per the checklist. He said that he was not a pilot, and that the pilot went over the details of the preflight with him as they moved around the airplane. There were no anomalies noted during the preflight, engine start, run-up, or during taxi. The takeoff was "normal," and the airplane climbed to about 1,500 feet. The passenger said that at that point of the climb, without warning, there was a loud metallic-sounding explosion, and oil sprayed onto the windscreen. He said, "It sounded like someone threw a big chunk of metal in the engine, and the engine cowling opened up like a can of sardines." At the same time, a section of the propeller departed the airplane. The passenger said that the pilot maneuvered the airplane toward an open area bordered by trees, and that the airplane lacked the altitude to clear the treetops. The airplane struck the trees, burst into flames, and then collided with terrain. The passenger escaped the wreckage, but burned his hands in his efforts to assist the pilot. The pilot held a private pilot certificate with a rating for airplane single engine land. He was issued a third-class medical certificate in April 2005. In a telephone interview, a flight instructor acquainted with the pilot stated that the pilot had accumulated about 160 total hours of flight experience. A subsequent exam of the pilot's logbook revealed that the pilot had logged 155 hours of flight experience. An examination of the airplane's maintenance records revealed the airplane was manufactured in 1972, and had accrued approximately 4,813 total aircraft hours. The airplane's most recent annual inspection was completed October 26, 2005, at 4,765 aircraft hours. The airplane's engine had accrued a total of about 4,700 hours of operation, and about 475 hours since overhaul. At 1251, the weather reported at New Castle Airport (ILG), Wilmington, Delaware, about 10 miles southeast, included clear skies with 10 miles visibility. The winds were from 300 degrees at 10 knots, gusting to 17 knots. The temperature was 66 degrees Fahrenheit, and the dew point was 41 degrees Fahrenheit. The airplane was examined at the site by a Federal Aviation Administration (FAA) inspector, and with the exception of a propeller blade, all major components were accounted for at the scene. A nearby resident later recovered the broken segment of propeller. The airplane was destroyed by impact and postcrash fire. After the initial examination, the airplane was moved to a recovery facility. The engine was removed, and transported to an engine overhaul facility for examination. The propeller, and the associated broken segment, were removed and transported to the Safety Board's Materials laboratory in Washington, D.C. The engine was examined at the Lycoming Engine Factory, Williamsport, Pennsylvania on May 2, 2006, under the supervision of the Safety Board. Examination revealed no preimpact anomalies or mechanical deficiencies. The propeller and the associated broken segment were examined at the Safety Board Materials Laboratory on July 12, 2006. Examination revealed that a large portion of the fracture surface displayed crack arrest positions typical of fatigue cracking. The fracture features emanated from an origin area on the camber (forward) surface of the propeller. Microscopic examination revealed an area of corrosion around the fatigue origin, as well as sanding scratches and conversion (Alodine) coating. Examination of the airplane's maintenance records revealed that on April 6, 1995, an entry stated, "Remove paint, remove damage from face of blades, correct angles, dress, track, balance, alodine, and repaint." A subsequent entry dated May 7, 1998 stated that the propeller was "repitched to 60" following an engine overhaul and conversion. Entries dated July 6, 2001 and July 25, 2002, reflected annual inspections respectively, each included "filed and inspected prop" in the text.

Probable Cause and Findings

Separation of the propeller blade due to fatigue.

 

Source: NTSB Aviation Accident Database

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