Atmore, AL, USA
N44903
PIPER PA 28R-201T
The private pilot and the passenger departed on a cross-country flight. The pilot stated that the airplane was at an altitude of 4,500 ft mean sea level when the engine lost oil pressure, followed by a total loss of engine power. The pilot landed the airplane on a two-lane country road. During the landing roll, the airplane's right wing struck mailboxes, which caused substantial damage to the right wing. Examination of the engine revealed the torque values for the No. 2 cylinder upper through bolt nuts, both No. 3 cylinder through bolt nuts, and the No. 5 cylinder through bolt nuts were below factory specifications for breakaway torque. Further examination revealed that the No. 3 connecting rod was separated from the crankshaft, the No. 2 main bearings had shifted, and there were signs of oil starvation. The likely insufficiently torqued nuts allowed the No. 2 bearings to shift and rotate, which resulted in oil starvation to the corresponding connecting rods and main bearings and ultimately led to the failure of the No. 3 connecting rod, ancillary damage to other internal components of the engine, and a total loss of engine power. Review of maintenance records revealed that the No 3. cylinder had been removed and reinstalled about 1 year before the accident. The engine's most recent annual inspection was completed about 9 months before the accident. There were no irregularities noted, and all airworthiness directives were complied with as noted by the mechanic. The investigation could not determine whether the loosening of the nut torque was due to improper installation or another unrelated issue.
On September 7, 2015, about 1530 central daylight time, a Piper, PA-28R-201T, N44903 was substantially damaged during a forced landing near Atmore, Alabama, about 30 minutes after departure from Foley Municipal Airport (5R4), Foley, Alabama. The private pilot and passenger were not injured. The airplane was registered to Treehouse Aviation LLC and operated by the pilot. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the flight that was enroute to Tuscaloosa Regional Airport (TCL), Tuscaloosa, Alabama.The pilot reported that after departure from 5R4 at a cruise altitude of 4,500 ft and level, the engine lost oil pressure; about 2 minutes later, the engine started losing power rapidly. The pilot knew he would not be able to make it to an airport, so he elected to make an off airport landing. He declared an emergency with Pensacola approach and searched for a landing area. Several of the fields looked too rough, so he elected to land on a two lane country road that appeared to be clear of vehicles. The engine had completely stopped producing power and the propeller had stopped turning by the time he lined up for final approach. The pilot made an uneventful landing on the road, but during the landing roll out, the airplane struck several roadside mailboxes with the right wing. Examination of the accident site by a Federal Aviation Administration inspector revealed that during the landing roll out, the airplane right wing struck several mailboxes along the road, which resulted in damage to a 5-foot section of the right wing. The leading edge was compressed and buckled, and a section was split and detached from the wing ribs. Further examination revealed that there was evidence of an in-flight engine failure including a hole in the case, and expelled oil in and around the engine cowling. The engine was transported to the manufactures facility for disassembly and examination. During the disassembly process, the torque values for the flange nuts and through bolts were checked for their breakaway values. The No. 2 upper through bolt (414 in/lbs), both No. 3 cylinder through bolts (420/483 in/lbs) and the No. 5 through bolts nuts (384/506 in/lbs) were below factory specifications of 590/610 in lbs for breakaway torque. Upon case separation chunks of metal, metal shavings and gouges to the interior of the engine case was discovered. Further examination revealed that the No. 3 connecting rod was separated from the crankshaft, and there were indications the No. 2 main bearings had shifted and there were signs of oil starvation. Review of maintenance records revealed that the No 3. cylinder had been removed and reinstalled on March 19, 2014, at 113.75 hours of operation prior to the accident. The engine's most recent annual inspection was completed on December 1, 2014. At the time of the annual, the engine had accumulated 1,538.69 hours total time since major overhaul. There were no irregularities noted, and all airworthiness directives (AD) were complied with as noted by the mechanic. On April 27, 2015, at 1,581.79 hours total time since overhaul, the oil was drained and replaced, the air filter was changed, and all twelve spark plugs were replaced. No irregularities were noted during the inspection. At the time of the accident, the engine had accrued 1,614 total hours since major overhaul and had flown about 75 hours since the most recent annual inspection and 32 hours since the most recent oil change. The pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. The pilot's last Federal Aviation Administration (FAA) third-class medical certificate was issued on October 30, 2014. The pilot reported 1,413.1 flight hours as of the day of the accident. The four-seat, low-wing, retractable-tricycle-gear airplane was manufactured in 1977. It was powered by a Continental, TSIO-360-FB, 200-hp engine, equipped with a constant-speed, two-blade Hartzell propeller. Weather at the Whiting Field Naval Air Station (NSE) North Milton, Florida, about 29 nautical miles southeast of the accident site, at 1456, was reported as wind variable at 5 knots, visibility 10 statute miles, few clouds at 4,900 ft, temperature 32° C, dewpoint 19° C, altimeter setting 29.94 inches of mercury.
A total loss of engine power due to oil starvation caused by insufficiently torqued cylinder through bolt nuts, which caused bearings to shift and led to the subsequent failure of the No. 3 connecting rod.
Source: NTSB Aviation Accident Database
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