IAD05LA076

During the downwind leg of the closed traffic pattern flight, the crankshaft of the 1930's vintage aircraft engine failed aft of the propeller flange. As the propeller continued to rotate independent of the engine, the pilot attempted to return to the airport; however, the tailwheel struck wires, and the airplane impacted the ground.

On June 12, 2005, about 1545 eastern daylight time, an Aeronca C-3, N13002, was substantially damaged during a forced landing near New Garden Airport (N57), Toughkenamon, Pennsylvania. The certificated airline transport pilot received serious injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight, conducted under 14 CFR Part 91.

In a written statement, and during a telephone interview, the pilot reported that the accident flight was his second circuit around the traffic pattern for runway 24. The pilot extended the downwind leg, and during the turn to the base leg, the engine lost power. The power loss was further described as normal engine operation, and then a "clack" sound, followed by silence.

He then attempted to land on the runway, but the tailwheel contacted power lines, rapidly decelerating the airplane. The airplane subsequently impacted the ground about 200 feet short of the runway.

A Federal Aviation Administration (FAA) inspector examined the airplane and the engine following the accident. The inspector found that the engine's crankshaft had broken aft of the propeller flange. Additionally, it was noted that the propeller had remained attached, and was free to rotate independent of the engine.

During a telephone interview, the operator of the airplane stated that the airplane had been completely restored a number of years prior, and that the restoration included an overhaul of the airplane's engine.

According to the FAA aircraft registration database, the accident airplane was manufactured in 1932. It had accumulated about 1,100 total hours of operation at the time of the accident.

The pilot held an airline transport pilot certificate with a rating for airplane multiengine land, and a commercial pilot certificate with a rating for airplane single engine land. He received an FAA first class medical certificate on March 29, 2005, and on that date he reported 9,700 total hours of flight experience.

Review of records pertaining to the Aeronca C-3 and the E-113 engine revealed 2 service memos and a service bulletin addressing problems with the crankshaft. Two of the service memos, issued in 1936 and 1938, addressed the proper procedure for lapping the propeller hub to the crankshaft, and inspection of the propeller end of the crankshaft, respectively. The inspection was intended to detect cracking and avoid failure of the crankshaft. A subsequent, undated service bulletin offered to upgrade the originally installed tapered style crankshaft to a splined style crankshaft.

According to the operator, the accident airplane was equipped with a splined crankshaft.

The weather reported at New Castle Airport (ILG), Wilmington, Delaware, about 13 nautical miles southeast, at 1951, included winds from 190 degrees at 12 knots and clear skies below 12,000 feet.