HISTORY OF FLIGHTOn May 28, 2016, about 1515 Pacific daylight time, an experimental amateur-built VariEze airplane, N80681, impacted power lines and terrain following a total loss of engine power near Santa Paula, California. The airline transport pilot and passenger were fatally injured. The airplane was destroyed in the postcrash fire. The airplane was privately owned and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the local area flight which departed Santa Paula Airport (SZP), Santa Paula, California, about 1510. Two witnesses observed the airplane flying overhead about 200-300 ft above ground level (agl), and they heard the engine sputtering. The airplane descended from their view as it passed behind a hill. When the airplane came back into their view, it was in a steep 45° left turn. The airplane struck power lines, and then impacted the ground; the power lines were about 75-ft tall. Witnesses reported hearing an explosion, and then seeing fire erupt from the accident site. An ear witness to the accident reported that after the airplane took off, the pilot radioed him that his engine had quit. There were no further communications between the pilot and the ear witness. PERSONNEL INFORMATIONThe pilot, age 61, held an airline transport pilot certificate with ratings for airplane single- and multi-engine land. He also held a flight instructor certificate for airplane single- and multi- engine, instrument airplane, and a mechanic certificate for airframe and powerplant. The pilot was issued a Federal Aviation Administration (FAA) second-class medical certificate on July 18, 2015, with the limitation that he must wear corrective lenses. On that date, he reported 3,500 hours of total flight experience, with 30 hours accrued in the previous six months. Review of the pilot's personal logbook indicated that he had 2,525.8 total hours of flight experience, with 3.6 hours in the previous six months. AIRCRAFT INFORMATIONThe airplane, serial number 1424, was manufactured in 1980, and equipped with a Continental Motors, Inc., O-200-X (experimental), 100-hosepower reciprocating engine. Review of the airplane's maintenance logbook indicated that a condition inspection was completed on May 1, 2016, with no airframe total time noted. Previous entries indicated a total airframe time of 2,576.0 hours and a total engine time of 324.3 hours as of September 30, 2015. Additional aircraft records revealed that that a zero-time engine was installed new in the airplane on March 18, 2003. The engine was assembled from new parts obtained from Continental Motors Inc. (Teledyne Continental Motors) in August of 2002. In December of 2002, a new crankshaft from A.E.R.O., Inc. was shipped to the builder. After the rebuild was completed, the engine was installed in the airplane in May 2003. AIRPORT INFORMATIONThe airplane, serial number 1424, was manufactured in 1980, and equipped with a Continental Motors, Inc., O-200-X (experimental), 100-hosepower reciprocating engine. Review of the airplane's maintenance logbook indicated that a condition inspection was completed on May 1, 2016, with no airframe total time noted. Previous entries indicated a total airframe time of 2,576.0 hours and a total engine time of 324.3 hours as of September 30, 2015. Additional aircraft records revealed that that a zero-time engine was installed new in the airplane on March 18, 2003. The engine was assembled from new parts obtained from Continental Motors Inc. (Teledyne Continental Motors) in August of 2002. In December of 2002, a new crankshaft from A.E.R.O., Inc. was shipped to the builder. After the rebuild was completed, the engine was installed in the airplane in May 2003. WRECKAGE AND IMPACT INFORMATIONThe accident area was in a rural part of Santa Paula. To the northwest of the accident site was a road and an open field. The field was unplanted and open but had furrowed rows. Adjacent to the road was the lemon orchard where the airplane came to rest. The initial impact point was identified as powerlines about 162 ft south of the main wreckage. A debris path extended from the powerlines on a magnetic heading of 325°. The airplane came to rest on a magnetic heading of 140° and was consumed by a postcrash fire. All major components of the airplane were accounted for at the accident site, and control continuity was established to each of the flight control surfaces. Visual examination of the engine revealed varying degrees of thermal damage. The engine was equipped with a Light Speed Engineering, LLC, electronic ignition system. The mounting pads for the magnetos, mechanical fuel pump, electric starter, and vacuum pump were covered by blank plates. The ignition harness was thermally damaged. The throttle cable arm remained secured at the throttle plate shaft. The throttle cable arm and the carburetor mixture arm could not be tested for proper operation due to the thermal damage. Internal timing of the engine was compromised due to mechanical damage to the crankshaft cluster gear and the camshaft gear. The top spark plugs were removed. The spark plugs from cylinder Nos. 1, 2, and 4 were oil contaminated; cylinder No. 3 was dry and exhibited normal combustion signatures. The oil pump was disassembled. The cavity displayed some scratches on the walls. The oil pump gears exhibited pitting of the gear teeth surfaces. The oil filter was disassembled, and the internal paper filter element had turned to ash because of the postcrash fire. All four cylinders remained intact but sustained thermal damage. The valves were intact with no signs of mechanical damage. The rocker arms were intact and in place. The piston rings and pins showed no visible damage. The Nos. 1, 2, and 4 connecting rods and caps were normal and the rod bearings exhibited normal coloration and wear patterns. The No. 3 connecting rod and cap appeared normal; however, the rod bearings were pitted on the surface material. The engine was rotated manually; it rotated fully in one direction, but binding was noted during rotation in the opposite direction. The engine crankcase was separated. The engine data plate had sustained thermal damage and was unreadable. The main bearings on the left crankcase half exhibited a dark coloration and some pitting. The main bearings on the right crankcase half, displayed normal coloration and wear patterns. The rear and center main crankshaft bearing journals were dark and discolored. The crankshaft cluster gear and the camshaft gear exhibited mechanical damage. The camshaft appeared normal. MEDICAL AND PATHOLOGICAL INFORMATIONThe Ventura County Medical Examiner's Office, Ventura, California, performed a postmortem examination of the pilot. The cause of death was reported as thermal injuries due to an aircraft accident. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed forensic toxicology on specimens from the pilot. The results were negative for carbon monoxide, volatiles, and tested-for-drugs. A cyanide screen was not performed. The toxicology report yielded positive results for: 21 (mg/dl) Glucose detected in Vitreous 519 (mg/dl) Glucose detected in Urine 5.6 (%) Hemoglobin A1C detected in Blood (Cardiac) TESTS AND RESEARCHThe crankshaft with camshaft drive gear cluster, main bearings, and the camshaft with gear were submitted to the National Transportation Safety Board Materials Laboratory in Washington, DC, for further examination. The crankshaft was intact but discolored at several bearing locations. All three main bearing journals and cylinder Nos. 2 and 3 journals were darkened on the same side; consistent with thermal damage from the postcrash fire. The camshaft drive gear ring of the crankshaft gear cluster displayed 9 consecutive fractured gear teeth. Large pieces of 8 of the teeth were recovered from the oil sump, along with several smaller pieces. A magnified optical examination of the fractured gear teeth surfaces revealed fatigue progression beach marking on the fracture surfaces of teeth Nos. 1, 2 and 3. The remaining teeth fractures were consistent with overstress. Scanning electron microscope imaging verified that the fatigue initiation location was near the base of each tooth, about 0.025 inches outboard of the root diameters for teeth Nos. 1 and 2.