Piper PA23 N1153P accident near San Juan, Puerto Rico

Probable cause

The total loss of right engine power for reasons that could not be determined because postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation.

NTSB analysis

According to the commercial pilot, before departing for the personal flight, he had the airplane fueled with a total of 50 gallons of 100LL aviation fuel (25 gallons of fuel in each wing tank). He then performed an engine run-up and noted that all parameters were "normal." After the airplane became airborne, it obtained a positive climb rate of 500 ft per minute. When the airplane reached about 300 ft above ground level, the right engine experienced a total loss of power. The pilot subsequently feathered the propeller but noticed that the airplane was unable to maintain altitude, so he performed an emergency landing to a lagoon.

A postaccident examination of the right engine confirmed crankshaft continuity; however, two of the four cylinders exhibited low compression ratios. The right engine-driven fuel pump, carburetor, and fuel selector were disassembled and examined, and corrosion was noted in all of the components. It could not be determined if the corrosion was a result of the airplane being submerged in salt water after the accident or if it was present before the accident. Wreckage examination and component testing did not reveal a mechanical reason for the partial power loss. The reported weather conditions were conducive to serious carburetor icing at glide power; however, the engine was operating at a high power setting for takeoff; therefore, it is unlikely that carburetor ice caused the total loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA15LA151 for the full record.