Accident Overview
On April 15, 2016, at approximately 1010 eastern daylight time, a Cessna U206F (registration N1346Q) was ditched in the international waters of the Atlantic Ocean about 23 nautical miles east of the shoreline of North Miami Beach, Florida. The private pilot and two passengers were not injured. The airplane was not recovered and was considered substantially damaged. The airplane was registered to Aircraft Guaranty Corp Trustee and operated by a private individual under 14 CFR Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed.
Flight Details
The flight originated from Fort Lauderdale Executive Airport (FXE), Fort Lauderdale, Florida, at about 0955, and was destined for South Bimini Airport (MYBS), North Bimini, Bahamas. The pilot stated that prior to departure, he performed a preflight inspection that included checking the oil quantity, which was full. The preflight inspection and engine run-up before takeoff were satisfactory with no discrepancies noted; oil pressure was satisfactory. The flight proceeded with visual flight rules flight following.
Engine Failure and Ditching
About 20 minutes from the destination, the pilot noted a rapid decrease in oil pressure and saw smoke coming from the engine cowling. The engine then ceased producing power. He declared an emergency with the air traffic controller, briefed the passengers on ditching procedures, and ditched the airplane near two boats. All occupants exited the airplane, boarded a life raft, and shortly afterward another airplane orbited their position. They were rescued by a yacht that motored to their location. The airplane's permanent maintenance records were on board and not recovered.
Maintenance History
The day before the accident, an airframe and powerplant mechanic with inspection authorization performed an oil and oil filter change. He visually inspected the oil filter adapter, found no evidence of oil seepage, and confirmed it was tightly installed. He torqued the Tempest AA48108-2 oil filter to 16 ft/lbs and safety wired it. After the change, he ran the engine twice to about 1,800 rpm with the cowling installed, observing no issues. After each run, he checked for oil leaks and found none associated with the oil change, but noticed dampness at the starter adapter pulley. He cut open the used oil filter and found only normal carbon deposits. He did not submit an oil sample for analysis. He returned the airplane to service with a handwritten entry in the maintenance records and did not make a copy. After the ditching, he inspected the ramp where the airplane had been parked and found no evidence of oil leakage.
Documents indicated the engine was overhauled by an FAA-approved repair station in August 2007 and installed. In May 2008, a full-flow oil filter adapter was installed per Supplemental Type Certificate SE09356SC. The same mechanic who performed the recent oil change had installed the adapter and reported applying anti-slippage material at two places: the top of the hex head and the bottom of the casting where it met the accessory case. According to the pilot, the engine had accrued about 700 hours since major overhaul.
The oil filter adapter's Instructions for Continued Airworthiness specified to inspect for oil seepage, safety wire security, and fit integrity.
Investigation
The captain of the rescue yacht reported the water depth was about 2,360 feet. Due to the depth, the insurance adjuster indicated the airplane would not be recovered and could not be examined. The accident occurred in international waters; therefore, the investigation was the responsibility of the U.S. National Transportation Safety Board under ICAO Annex 13.