On May 31, 2001, about 0935 eastern daylight time, a homebuilt Nieuport 24, N1893, experienced an in-flight propeller failure and was substantially damaged during a forced landing in Evesham Township, New Jersey. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the flight that departed South Jersey Regional Airport (VAY), Mount Holly, New Jersey, destined for the New Garden Airport (N57), Toughkenamon, Pennsylvania. The ferry flight was conducted under 14 CFR Part 91. In a telephone interview, the pilot stated he performed a normal pre-flight inspection and engine run-up prior to takeoff. Approximately 7 to 10 minutes after takeoff, while in cruise flight about 1,400 feet msl., the pilot heard a "loud bang" and experienced severe vibration. He then shut down the engine and performed a forced landing to a field. The airplane nosed over during the landing and came to rest inverted. The wreckage was examined by a Federal Aviation Administration inspector. The inspector stated that one of the airplane's wooden propeller blades had split down it's longitudinal axis and separated in-flight. The remainder of the propeller remained attached to the engine. According to the owner, the propeller installed on the airplane was uncertificated and built specifically for the accident airplane, which was a replica of a World War I fighter. The airplane, engine, and propeller had been operated for about 3 hours of flight time, and 5 to 7 hours of ground tests.