ERA15LA133

The inadequate maintenance and inspection of the fuel system, which resulted in partial blockage of a fuel filter, a partial loss of engine power, and subsequent ditching.

The private pilot had just purchased the experimental, amateur-built airplane on the day of the accident following a short flight with the previous owner. The pilot purchased premium automobile gasoline at a local gas station and refueled the airplane for the flight to his home airport. He and his passenger then boarded the airplane and taxied for takeoff. After takeoff, the pilot climbed the airplane along the shoreline to about 1,000 ft above sea level. About 20 minutes into the flight, the pilot noticed that the engine was not producing enough power to sustain level flight, so he began to troubleshoot while he flew a course parallel to the shoreline over shallow water. Due to people and rocks along the shoreline, he decided not to land on the beach, but to ditch the airplane in the water. Upon touchdown, the airplane decelerated and sank. The pilot released his seatbelt, egressed, and swam to the surface. When the pilot reached the surface, he did not see his passenger. He swam back down to the wreckage, released the passenger's seatbelt, and swam him up to the surface. However, the passenger was not breathing and cardiopulmonary resuscitation was unsuccessful. Examination of the airplane's fuel system revealed that the single fuel filter located between the electric fuel pump and the primer plunger was full of sand and debris, which obstructed the mesh filter screen. The condition of the filter indicated that it was not being maintained and inspected regularly, even though the fuel filter had a transparent housing and was in a location that allowed it to be inspected easily. The airplane build manual, engine operator's manual, engine installation manual, and engine maintenance manual all called for frequent inspection of the fuel filter. According to the maintenance manual, the flow through the filter could be restricted due to long-term buildup of dirt, and the fuel filter should be inspected every 25 hours of operation and replaced every 100 hours of operation. Review of the airplane's maintenance records found no entries indicating the inspection or replacement of the fuel filter since 2009, when a new engine was installed. The airplane's most recent condition inspection was performed about 3 months before the accident.

The Rans S-6ES Build Manual, under the "Fuel System" subsection of the "Inspection of Engine Systems" section called for a check for "fuel filter clogs." The Rotax Operators Manual stated, "check engine suspension frequently as well as the drive components, fuel lines, wiring, and fuel and air filters." Under "Daily Checks," it stated, "inspect all fuel hose connections, filters, primer bulbs and taps for security, leakage, chafing and kinks." The Rotax Installation Manual also stated, "check engine suspension frequently as well as the drive components, fuel lines, wiring, and fuel and air filters." It stated, "fuel contamination is a major cause of engine failures. The best place to avoid contamination is at the source. Once fuel is in your container, a very hazardous potential exists. Use a clean safety approved storage container. Filter all fuel entering and leaving this container." (It is unknown what method, if any, the previous owners used to filter fuel before filling the airplane's fuel tanks). The Rotax Maintenance Manual also stated, "check engine suspension frequently as well as the drive components, fuel lines, wiring, and fuel and air filters." The maintenance schedule required that the fuel filter be checked every 25, 50, and 75 hours of operation and be replaced every 100 hours of operation. Section 11.8, "Check and Replacement of Fuel Filter" stated, "the flow through the filter may be restricted due to long term buildup of dirt. A more serious type of blockage, which can occur quite rapidly is caused by a reaction between detergents in certain two-stroke oils and water in the fuel. Both types of blockage may be difficult to detect visually. If blockage is suspected, renew fuel filter or filter element. Subsequently avoid water contamination of fuel." Examination of the airplane and engine maintenance records did not find any entries related to the fuel filter. Based on the engine serial number, the engine was manufactured on April 17, 2008. The Rotax Maintenance Manual (Section 10.2 - Maintenance Schedule) stated that general overhaul of the engine should be carried out every 5 years, or every 300 hours, whichever comes first. Maintenance records did not indicate that the engine had been overhauled since its installation in 2009. The Puerto Rico Institute of Forensic Sciences performed an autopsy on the passenger. The passenger's cause of death was asphyxiation by drowning. Toxicological testing of the passenger was conducted at the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The specimens from the passenger were negative for carbon monoxide. Loratadine, a non-sedating tricyclic antihistamine, was detected in blood. Ranitidine, an antihistamine used in the treatment of gastric acid secretion, was detected in blood and urine. On February 21, 2015, the wreckage of the airplane was recovered from about 20 ft of water about 200 ft off the beach near Rincon and transported to the Port of Mayaguez. Examination of the airplane and engine revealed that the firewall and engine mounts were bent and broken, and the engine had been removed during the recovery. Both carburetors were displaced from their mounting positions, the coolant lines had been cut, and all spark plugs had sustained impact damage. The propeller was still attached to the engine gearbox, and all three propeller blades remained attached to the propeller hub. Surface corrosion could be seen on all exposed aluminum parts of the airplane, which was consistent with the airplane's submergence in sea water. Engine Examination of the intake system revealed that the air filters were the proper type but had suffered damage from impact or recovery of the wreckage from the ocean, and the element pleats were packed with dirt and sand. Examination of the exhaust system revealed that a large section of the exhaust system was missing. Only the exhaust "Y" pipe, the first portion of exhaust system which connected both cylinders to a single section of exhaust pipe and held the two exhaust gas metering probes, was still attached to the engine. Examination of the spark plugs and dual capacity discharge ignition system revealed that the spark plugs were impact damaged, had non-conforming removable resistor caps, and had rust-colored water droplets on them, which was indicative of sea water being present in the combustion chambers. The ignition modules were of the proper type and in good physical condition. The ignition wires also of the proper type and had incurred impact damage. Examination of the coolant system revealed that the overflow bottle was missing; all the coolant hoses were breached; the water pump was intact; and the coolant radiator was still attached to the firewall but was heavily damaged. There was no evidence of coolant remaining in the system. Examination of the injection oil lubrication system revealed that it had been disconnected and was no longer operational. This required the pilot to premix the fuel with oil at a 50:1 ratio before pouring it into the airplane's fuel tanks. Examination of the rotary lubrication system revealed that the system and the oil tank were contaminated with sea water, and the perpendicular shaft and rotary valve plate were corroded due to submersion. An attempt to rotate the crankshaft by turning the propeller shaft by hand to establish thumb compression and drivetrain continuity was unsuccessful. The propeller shaft would not rotate indicating that something internally was preventing this action. The propeller was removed, and the engine was placed on a work bench for further inspection and disassembly. Examination of the reduction gearbox revealed that lubrication gear oil was still contained within the gearbox, and the gear-set and bearings appeared to be in good condition. Examination of the combustion chamber revealed that the cylinder heads were in good physical condition. Examination of the power takeoff side (PTO) cylinder and the magneto side (MAG) cylinder revealed that the cylinder heads were in good physical condition. Both displayed a reddish coating of iron oxide (rust) on the barrel surface. No seizure marks or mechanical anomalies could be seen on either the PTO or MAG cylinders. Due to the stuck position of the crankshaft, the MAG piston could not be removed from its connecting rod, and the crankcase could not be spilt open. Inspection of the crankshaft and connecting rods was done though the connecting rod holes in the crank case. Corrosion from submergence in sea water was found on the connecting rods and crankshaft, and this was determined to be the reason the crankshaft could not be rotated. Other than the surface corrosion from the salt water submersion, no anomalies were found with the crankshaft, connecting rods, or bearings. Examination of the PTO piston through the exhaust port revealed severe corrosion and salt deposits. The piston was stuck in the top dead center position; it could not be rotated to reveal the condition of the piston rings or cylinder bore; and it displayed a reddish colored coating of iron oxide (rust). There were no signs of vertical scoring, metal transfer, or excessive heat signatures seen on the exhaust side of the PTO piston. There were no indications of piston seizure, detonation, or mechanical anomalies. Examination of the MAG piston through the exhaust port also revealed severe corrosion and salt deposits. The piston was stuck in the bottom dead center position and could not be rotated to reveal the condition of the side of the piston. The cylinder bore, top of the piston, and piston rings were exposed and could be examined for anomalies. Severe corrosion and salt deposits could be seen on all the metal surfaces, and the piston rings were stuck in their respective ring groove lands. As with the PTO piston, the MAG piston also had a reddish coating of iron oxide (rust) on its surface, and no indication of a piston