HISTORY OF FLIGHTOn September 18, 2014, about 1145 central daylight time, a kit-built Seawind 3000 seaplane, N516SW, impacted terrain near Bloomington, Indiana. The private rated pilot and pilot rated passenger were fatally injured, and the seaplane was destroyed. The seaplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and a flight plan was not filed. The pilot contacted the control tower operator at Monroe Country Airport (KBMG) and reported he had a low fuel pressure indicator problem and they planned to fly directly to the airport. Several witnesses reported seeing the seaplane flying, with one witness noting that the seaplane was on fire prior to the aircraft impacting terrain. PERSONNEL INFORMATIONThe pilot held a private pilot certificate with ratings for airplane single-engine land and sea. He also held instrument-airplane and repairman experimental aircraft builder ratings. The pilot's last class 3 medical exam was conducted on November 21, 2012. At the time of the exam, the pilot reported his flight experience as 765 total flight hours and 20 hours in last six months. The passenger held a private pilot certificate with ratings for airplane single-engine land and sea. The passenger's last class 3 medical exam was conducted on December 12, 2012. At the time of the exam, the passenger reported his flight experience as 3,400 total flight hours and 50 hours in last six months. AIRCRAFT INFORMATIONThe Seawind is a kit built, composite structure, four seat, amphibian airplane, with a single tail-mounted engine. The airplane was powered by a 300 horsepower (HP) Lycoming IO-540-K1A5 reciprocating engine, which drove a Hartzell, 3 blade, constant speed propeller. A review of Federal Aviation Administration (FAA) records revealed the accident airplane received its special airworthiness certificate in the experimental amateur-built category on September 20, 2007. METEOROLOGICAL INFORMATIONAt 1153, the automated weather observation facility located at KBMG, reported wind from 110 degrees at 4 knots, visibility 10 miles, a clear sky, temperature 68 Fahrenheit (F), dew point 50 F, and a barometric pressure of 30.09 inches of mercury. AIRPORT INFORMATIONThe Seawind is a kit built, composite structure, four seat, amphibian airplane, with a single tail-mounted engine. The airplane was powered by a 300 horsepower (HP) Lycoming IO-540-K1A5 reciprocating engine, which drove a Hartzell, 3 blade, constant speed propeller. A review of Federal Aviation Administration (FAA) records revealed the accident airplane received its special airworthiness certificate in the experimental amateur-built category on September 20, 2007. WRECKAGE AND IMPACT INFORMATIONThe seaplane impacted terrain about 3 miles north of KBMG, in a lightly wooded area. A post-crash fire consumed much of the composite structure. Several pieces of composite material were located along the airplane's flight path; the material pieces had evidence of burn areas, consistent with an in-flight fire. After an initial documentation and examination of the wreckage site, the wreckage was removed for examination at a nearby facility. MEDICAL AND PATHOLOGICAL INFORMATIONThe Lawrence County Coroner's Office, Bedford, Indiana, conducted an autopsy on the pilot and pilot rated passenger. The cause of death on both occupants was determined to be injuries sustained in an aircraft crash. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, conducted toxicologically testing on the on both occupants. The specimens were negative for tested items. TEST and RESEARCH Examination of the airplane was conducted; the fire had destroyed the majority of the airplane. The engine's 3-bladed propeller remained attached to the crankshaft. All three blades exhibited signs of fire/thermal damage, with one blade missing the outboard tip. One blade exhibited slight aft bending, starting about 12 inches from the tip. The engine's fuel servo and fuel pump were destroyed by the fire, and identification part and serial numbers could not be found. The fuel flow divider was dissembled and had suffered thermal damage to the diaphragm. The fuel nozzles and lines to the flow divider were secure. Both magnetos sustained thermal damaged and could not be tested. The sparkplugs were removed and appeared to have normal wear. On the initial attempt to rotate the engine by manually rotating the propeller, the engine would only turn about 100 degrees before binding. The accessory case was removed and a large amount of melted aluminum was found within the gear train consistent with a melted aluminum case of a magneto. The melted aluminum was removed, and the crankshaft was able to rotate. Thumb compression and valve action was confirmed at each cylinder. The rear accessory gears rotated and mechanical continuity was established throughout the engine drive train. The fire/thermal damage limited a complete examination of the engine; however, based on the limited examination, there was no evidence of pre-impact mechanical malfunctions noted. During the examination, an electrical wire was found within the wreckage that had signatures consistent with fraying and a piece of metal attached. A fuel line was also found in the same area of the electrical wire that had signatures consistent with thermal damage. Both pieces would have been located in the vicinity of the tail and engine nacelle, a confined area of the tail structure near the engine nacelle. Sections of both materials were sent to the NTSB Materials Laboratory in Washington DC for further examination. The purpose of examining sections of the fuel line and electrical wire was to identify a potential source of an in-flight fire. The laboratory investigation consequently tried to find evidence of chafing and electrical arcing between the alternator cable and the fuel line. While the laboratory found some evidence of electrical arcing, the tested section was absent evidence of chafing and arcing between the two. A source of the in-flight fire was not found.