On June 6, 2002, a Cessna P206 (registration N2594X) was involved in an aviation accident near Manteo, NC. Investigators recorded the probable cause as: a total loss of engine power due to the failure of a connecting rod bolt because of fatigue, resulting in damage to the airplane during the subsequent ditching. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An airplane experienced partial power loss at 200 feet, then complete loss during a turn back. The pilot performed a water landing. Examination revealed fatigue in a connecting rod bolt.
Event Description
Shortly after takeoff, at an estimated altitude of 200 feet, the airplane's engine lost partial power. The pilot checked the throttle for full power and initiated a turn back to the departure airport under partial power. When the airplane reached a point approximately 90 degrees to the departure runway, the pilot reported that the engine power was lost completely and the airplane lost significant altitude. To avoid endangering homes on the shore, the pilot elected to perform a water landing. The airplane subsequently impacted in about 7 feet of water.
Engine Examination
A subsequent teardown of the engine revealed a hole in the upper case halves between cylinders 3 and 4. The connecting rods for cylinders 3 and 4 were broken from the wrist pin to the crankshaft. Laboratory examination of the fracture surfaces indicated that the threaded half of one connecting rod bolt exhibited a very flat fracture surface containing arrest marks and a thumbnail pattern characteristic of fatigue propagation. The fatigue region was found to occupy approximately 80 percent of the cross-sectional area.