On September 6, 2012, about 1135 eastern daylight time, a Beech 76, N6716L, was substantially damaged following a loss of directional control while landing at Central Jersey Regional Airport (47N), Manville, New Jersey. The private pilot and the pilot-rated passenger sustained serious injuries. The airplane was registered to N6716 LLC and was operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and no flight plan was filed. The flight originated at Princeton, New Jersey (39N) at 1030. The pilot reported the following. He was acting as pilot-in-command during the approach to runway 25. He occupied the left cockpit seat. Following a normal approach, the airplane touched down and began to drift left. He commenced a go-around about the same time that the passenger called out “full power.” The pilot applied full power, the airplane accelerated, and began to lift off. The airplane then began to turn and roll to the right. As he applied flight control inputs to correct the situation, the airplane rolled to the left and ultimately struck the ground. The passenger reported that, during the approach to runway 25, he had the right cockpit seat positioned aft and he was looking at his iPad. There was no wind or other weather issues at the time. The pilot flew a normal approach; however, he “did not touch down early enough.” The airplane “porpoised” back into the air after departing the left side of the runway. He advised the pilot to go around and the pilot added full power. The airplane gained altitude and pitched hard to the right. The passenger reported that, at no time during the flight, were simulated single engine procedures practiced. A witness on the ramp, who was a flight instructor, reported that the airplane was stabilized on final approach to runway 25 and the propellers were turning. The airplane touched down in the first third of the runway, bounced slightly, and then the pilot added power. When power was added, the airplane banked heavily to the right and reached an altitude of about 20 to 30 feet above the runway. He heard the power come back to idle and then the airplane banked to the left. The left wing then struck a dirt mound off the left side of the taxiway, the airplane struck a fence, and flipped over on its back. While the airplane was airborne, he did not observe any visual indications of an engine failure and the propellers were not feathered. A Federal Aviation Administration inspector responded to the accident site and examined the wreckage. He confirmed substantial damage to the wings, fuselage, and empennage. He reported that the right engine “did not appear to be operating.” The right mixture control was found in the idle cutoff position. Fuel was found in both wing tanks. The fuel selector valves tested normally in the “on” position. The wreckage was recovered to a storage facility where a subsequent examination of the airframe and engines was performed on March 20, 2013 by a NTSB Air Safety Investigator and a FAA Airworthiness Inspector. Examination of the right engine propeller blades revealed leading edge gouges and the blade tip of one blade was broken off. Further examination of the right engine revealed that compression was noted on all six cylinders and valve train continuity was confirmed when the engine was rotated manually. The right magneto produced spark to all leads except the number one cylinder bottom plug. The top spark plugs were removed and the electrodes exhibited normal wear and color when compared to a Champion Spark Plug inspection chart. The carburetor inlet screen was removed and examined; no contaminants were noted. The carburetor bowl contained fuel and no contaminants were noted. The right engine oil sump screen was removed and examined; no particulates were found. Examination of the left engine propeller blades revealed leading edge gouges, chord-wise surface scratches, and twisting of the blades. Further examination of the left engine revealed that compression was noted on all six cylinders and valve train continuity was confirmed when the engine was rotated manually. The left engine magneto produced spark to all leads when manually rotated. The top spark plugs were removed and the electrodes exhibited normal wear and color when compared to a Champion Spark Plug inspection chart. The carburetor inlet screen was removed and examined; no contaminants were noted. The carburetor bowl contained fuel and no contaminants were noted. The left engine oil sump screen was removed and examined; no particulates were found.