Accident Overview
On April 23, 2009, about 1500 eastern daylight time, a Piper PA-28R-200, registration N2938R, was substantially damaged during a forced landing near Hilliard, Florida. The airplane was operated by the pilot under 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated at Dallas Bay Sky Park Airport (1A0), Chattanooga, Tennessee, at 1245, destined for Winter Haven, Florida.
Sequence of Events
The pilot reported an uneventful flight until, while climbing to 9,500 feet mean sea level near Hilliard, he heard a loud bang from the engine compartment. The propeller began to slow, and he contacted Jacksonville Center for assistance. Vectors were provided to Hilliard Airpark (01J), but the engine stopped completely and the pilot could not glide to the airport. He selected an area for a forced landing. During the landing, the tail struck a tree, separating from the fuselage. After the airplane came to a stop, the pilot removed the engine cowl and observed that one cylinder had separated from the crankcase.
Examination Findings
An FAA inspector examined the wreckage at the accident site. Both fuel tanks contained sufficient fuel. The No. 3 cylinder was separated from the crankcase, with the connecting rod separated from the crankshaft and broken cylinder attachment studs. The empennage sustained structural damage. After recovery, the engine was examined again at a salvage facility. The FAA inspector found that nuts on four engine cylinder through bolts and two cylinder attachment studs had torque values lower than specified by the engine technical manual.
The separated cylinder stud and attachment bolt were sent to the NTSB Materials Laboratory. Examination under a bench binocular microscope revealed the fracture face contained crack arrest marks typical of fatigue cracking that emanated from multiple origins at the root of the threads. The origin of the fatigue cracks showed no evidence of corrosion or mechanical damage.
Maintenance History
The pilot purchased N2938R on December 5, 2008. According to maintenance records, the previous owner—a certificated airframe and powerplant mechanic—had performed a major engine overhaul per a logbook entry dated July 8, 2008. The previous owner reported using a calibrated torque wrench when installing cylinders during the overhaul. At the time of the accident, the engine had operated about 131 hours since overhaul. The pilot reported that the only maintenance performed after delivery was replacement of an engine starter ring gear.
Pre-Purchase Inspection
The previous owner reported delivering the airplane in December 2008. During the sale, the pilot had a mechanic perform a pre-buy inspection. The mechanic noted a suspect oil leak on the right, rear cylinder (closest to the front passenger seat). The mechanic recommended removing and replacing the cylinder base o-ring, and the buyer insisted on this repair before sale. The previous owner paid for the repair via an adjustment to the sales price; he did not observe the repair. A copy of the purchase agreement included a handwritten note: "On delivery of Aircraft, purchasers mechanic found signs of an oil leak @ cylinder bases and recommended replacing seals. Seller agreed to pay $250.00 to have purchasers mechanic replace cylinder o-rings."
The mechanic, interviewed by the NTSB, recalled that two engine cylinders were leaking oil around the bases, but could not recall which cylinders. He advised the pilot that the leaking cylinders would have to be removed to repair leaks and to negotiate a price reduction. He also told the seller about the leaks; the seller responded, "All engines leak a little bit," and the mechanic replied that a newly-overhauled engine should not leak oil.
Weather Conditions
The 1456 weather observation at Jacksonville, Florida (JAX), about 16 miles southeast of the accident site, included: few clouds at 4,000 feet, scattered clouds at 18,000 feet, surface winds from 280 degrees at 8 knots gusting to 15 knots, 10 statute miles visibility, temperature 30°C, dew point 12°C, and altimeter setting 30.17 inches of mercury.