On June 26, 1997, about 1735 eastern daylight time, a Piper PA-28-140, N859KW, registered to Juliet Sierra Aviation, Inc., collided with a tree during an emergency descent for a forced landing shortly after takeoff from the Orlando Sanford Airport, Sanford, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight. The airplane was substantially damaged and the private-rated pilot, the sole occupant, was not injured. The flight originated about 2 minutes earlier from the Orlando Sanford Airport. The pilot stated that after departure while in level cruise flight at 1,500 feet, he noted that the engine rpm was decreasing but the engine sounded normal. The engine rpm continued to decrease although full throttle was applied. While turning to return to the airport, the engine failed. He trimmed for the best glide airspeed, advised the tower, and began gliding toward an open field ahead and to the left of the flightpath of the airplane. While descending the airplane collided with and remained suspended in a line of palm trees that border the edge of the field. Postcrash examination of the airplane revealed oil on the bottom of the fuselage from the engine compartment area to the empennage. Examination of the engine by an FAA inspector revealed the flexible oil hose, Part Number 63901-72, from the engine-driven oil pump to the oil radiator was failed about 27 inches forward of the engine-driven oil pump outlet fitting. There was no evidence of chafing on the fire sleeve adjacent to the failed area. The hose had a band clamp around it which indicated that it was assembled in the first quarter of 1977. Review of the engine logbook revealed that the oil radiator hoses to and from the oil cooler were recorded as being replaced in accordance with Airworthiness Directive (AD) 76-25-06, on May 1, 1977. The AD was nonrepetitive. The tachometer time and airplane total time at replacement were recorded to each be 1,920.51 hours. There were no further entries which indicate that the hoses were replaced since that time. The logbook reflects no entries between an annual inspection that was performed on July 21, 1988, at an airplane total time of 4,136.0 hours and August 2, 1995, at an airplane total time of 4,139.22 hours. The airplane was last inspected on September 9, 1996, in accordance with an annual inspection. The airplane total time on that date was recorded as 4,233.7 hours. The tachometer time postcrash was recorded as 4,308.61 hours. The engine received a major overhaul on January 3, 1979, at a total time of 2,798.0 hours.