Accident Details
On March 9, 2015, at about 1200 Atlantic daylight time, a Piper PA-23-250, registration N1153P, was substantially damaged when it impacted a lagoon after the right engine experienced a total loss of power during initial climb near San Juan, Puerto Rico. Visual meteorological conditions prevailed and a visual flight rules flight plan was filed for the personal flight. The commercial pilot and one passenger were not injured. The flight was conducted under 14 CFR Part 91. The flight departed Fernando Luis Ribas Dominicci Airport (SIG) around 1200, with the intended destination of Cyril E. King Airport (STT), St. Thomas, U.S. Virgin Islands.
Pilot Account
According to the pilot, he had the airplane fueled with a total of 50 gallons of 100LL aviation fuel, 25 gallons in each wing. He performed an engine run up and all parameters were normal. The airplane departed runway 09; the pilot obtained a positive rate of climb of 500 feet per minute and an indicated airspeed of 105 mph. About 300 feet above ground level, the right engine experienced a total loss of power. The pilot identified the loss of power and feathered the propeller. Noticing the airplane could not maintain altitude, he looked for a landing site. He identified the lagoon off to the right as the safest option and maneuvered for an emergency landing in the water. During final approach, he set the right engine mixture to off and shut down the left engine. After impact, the pilot and passenger egressed without injury, and the airplane became submerged.
Witness Observations
Witnesses reported hearing the airplane sputter and pop, then the engine went quiet. They looked up, saw grey smoke from the right engine, and observed the airplane bank toward the lagoon. The airplane continued toward the lagoon and was lost from sight behind a building.
Aircraft Information
According to FAA records, the airplane was manufactured in 1956 and registered to an individual in 2008. It was powered by two Lycoming O-320 150-hp engines. Maintenance records showed the most recent annual inspection was signed off on June 26, 2014. The right engine recorded a time of 735.5 hours since overhaul at that inspection. Compression testing at the annual inspection recorded Cylinder Nos. 1, 2, and 4 at 72/80 and Cylinder No. 3 at 70/80. A fuel receipt dated March 9, 2015, noted 30 gallons of fuel was purchased for the accident airplane.
Postaccident Examination
The airplane was recovered from the lagoon. A postaccident examination on March 16, 2015, confirmed crankshaft continuity on both engines. Compression testing on the right engine found no compression in Nos. 2 and 4 cylinders. The ignition system and fuel system were visually checked with no damage noted. The right engine-driven fuel pump showed no anomalies. Differential testing the following day found compression ratios of 60/80 in cylinder No. 1, 10/80 in cylinder No. 2, 60/80 in cylinder No. 3, and 10/80 in cylinder No. 4.
The right carburetor, fuel selector, and shut-off valves were removed; evidence of 100LL aviation fuel was noted. The carburetor was disassembled; finger screen, main jet, and needle valve exhibited corrosion. The butterfly valve operated normally, but the float was removed with corrosion. Liquid in the float chamber had an odor similar to ocean water. The engine-driven fuel pump was disassembled; corrosion was noted on the fuel screen, and an odor of 100LL fuel was present. The fuel gascolator was disassembled; corrosion was noted in the bowl, and no fuel screen was found inside. The main fuel shut-off valve was in the ON position with no blockages. The right fuel tank selector was in the forward position (main tank selected), and the right fuel selector guard was engaged. The airframe fuel system was not thoroughly examined by FAA inspectors after the accident.
Weather Conditions
A review of recorded data from the Fernando Luis Ribas Dominicci Airport automated weather observation station around the accident time indicated wind from 110 degrees at 12 knots, 10 miles visibility, scattered clouds at 3,000 feet AGL, temperature 26°C, dewpoint 21°C, and an altimeter setting of 30.13 inches of mercury. The carburetor icing probability chart from FAA SAIB CE-09-35 shows a probability of serious icing at glide power at the reported temperature and dewpoint.