NTSB Factual Report

On May 13, 2005, about 2300 eastern daylight time, a Piper PA-28-140, N55165, was substantially damaged following a collision with terrain during the initial climb from the Chandelle Estates Airport (0N4), Dover, Delaware. The certificated commercial pilot and two passengers received minor injuries. Night visual meteorological conditions prevailed, and no flight plan was filed for the personal flight, destined for the Lehigh Valley International Airport (ABE), Allentown, Pennsylvania, which was conducted under 14 CFR Part 91.

According to the pilot, after completing the pre-takeoff checklist, and normal engine runup, he departed runway 22 at Chandelle Estates Airport. During the initial climb he noticed a "substantial decrease" in power. He lowered the nose of the airplane to gain airspeed, and adjusted the throttle control in an attempt to regain engine power, without result. The pilot subsequently performed a forced landing to a field approximately 1/2 mile from the departure end of the runway.

Examination of the Airplane by a Federal Aviation Administration (FAA) inspector revealed that during the forced landing, the right wing had separated at the wing root, the left wing outer wing panel was wrinkled and twisted, the fuselage exhibited compression buckling in multiple locations, all three landing gear legs were broken off and the engine had been displaced approximately 10 degrees to the right and down 5 degrees.

No preimpact mechanical malfunctions of the engine were noted; however, examination of the exhaust system revealed that a portion of the internal baffle in the muffler assembly had separated from the surrounding structure, and was free to move around inside the muffler. Further examination of the exhaust system showed that the tailpipe was equipped with an arch shaped standoff assembly that extended from the inboard end of the tailpipe and protruded into the muffler.

According to the FAA inspector, the arch shaped standoff was designed to extend far enough into the muffler to prevent a loose exhaust baffle from covering the inboard end of the tailpipe. Examination of the alignment holes on both the tailpipe and muffler revealed that when both holes were aligned, the standoff assembly did not protrude far enough into the muffler to keep the loose portion of the baffle from blocking the tailpipe.

The Piper Cherokee Service Manual states, "The entire exhaust system, including heat exchange shroud, muffler, muffler baffles, stacks and all exhaust connections must be rigidly inspected at each 100-hour inspection. The possibility of exhaust system failure increases with use. It is recommended that the system be checked more carefully as the number of hours increase, therefore inspection at the 700 hour period, that the exhaust system has been in use would be more critical than ones in the 100 hour period." It goes on to state, "Removal of the tail pipe and stacks is required for inspection of the muffler baffle. Remove or loosen all exhaust shields, carburetor and cabin heat muffs, shrouds, heat blankets, etc., as required to permit inspection of the complete system. Perform the necessary cleaning operations and inspect all external surfaces for dents, cracks and missing parts. Pay particular attention to welds, clamps. supports and support attachment lug's, slip joints. stack flanges and gaskets. Inspect internal baffle or diffusers. Any cracks, warpage or severe oxidation are cause for replacement of the muffler. Additionally, it states, " NOTE: It is recommended that all PA-28 airplanes be fitted with a new muffler at or near the 1000 hour period of which the muffler has been used."

The airplane was manufactured in 1973. According to the airplane's maintenance records, a "newly overhauled tail pipe" was installed at 4510.77 total hours of operation. The airplane's most recent 100 hour inspection was completed on March 31, 2005. At the time of the inspection, the airplane had accrued 5574 total hours of operation. At the time of the accident, the airplane had operated 76.14 hours since its last inspection.

NTSB Probable Cause

The separated baffle which blocked the tailpipe resulting in a subsequent total loss of engine power.