On May 29, 1997, about 1500 eastern daylight time, a Piper PA-25-235, N4497Y, was substantially damaged during a precautionary landing in Preston, Maryland. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed for the local aerial application flight which originated at Laurel Airport, Laurel, Delaware, about 1400. No flight plan had been filed for the flight which was conducted under 14 CFR Part 137. The NTSB Pilot/Operator Report, submitted by the pilot's lawyer more than 60 days after the accident and after the airplane was disassembled, stated: "...[the pilot] experienced a loss of power due to a problem with the left magneto...He performed a precautionary landing in a field near Preston, MD, which resulted in very slight damage to the bottom of the tail, strut cords and right wing...There were no injuries and it was determined to be a non-reportable incident." According to written reports from the Federal Aviation Administration (FAA), the front and rear spars of the right wing were replaced, the landing gear bungees were broken, and a tube member was bent and cracked for the tail section which mounts the rudder.