On July 12, 2000, about 1710 Eastern Daylight Time, a Fairchild M-62C (PT-23), N58741, was substantially damaged while departing a private, non-designated airport in Carthage, New York. The certificated private pilot received serious injuries, and the pilot rated passenger received minor injuries. Visual meteorological conditions prevailed for the personal flight. No flight plan had been filed for the flight that was conducted under 14 CFR Part 91. According to the pilot, he had landed earlier in the day at the airport. The airplane was serviced and he offered a ride to the passenger, which was accepted. The pilot reported the takeoff was initiated with him sitting in the rear cockpit, and the passenger in the forward cockpit. Trees, about 50 feet high were located on the departure end of the runway. The pilot reported that after the airplane became airborne, there was insufficient room to accelerate to the optimum climb speed of 80 mph, and climb above the trees. The pilot then aimed the airplane for a low spot in the trees. The airplane struck trees, and came to rest in a parking lot between two buildings beyond the trees. Both wings and the engine separated from the fuselage. The pilot reported that he had operated out of the airport several times with a Cessna 172 with no problems. When asked about the grass, he reported he thought it was about 4 to 5 inches long. The pilot reported the winds were from 270 degrees to 290 degrees at 4 to 5 knots. The owner of the airport was the passenger. He reported the east/west turf runway was about 2,600 feet long and 300 feet wide. He thought the grass was about 3 inches high. Trees about 50 feet high were located on the west-end of the runway. Due to the trees, most flights land to the west toward the trees, and depart to the east, even with a tailwind, because there are no obstacles to clear. He said he mentioned this to the pilot who elected to depart to the west, over the trees. He reported the winds were from the northwest at 5 knots. The passenger also reported that when he saw they would not clear the trees, he also placed his hands on the flight controls along with the pilot. Both pilots reported a wind of about 5 knots from the northwest. The closest weather reporting was Wheeler-Sack AAF, Fort Drum, New York, located 7 nautical miles northwest of the departure airport. At 1655, they reported winds from 020 degrees at 8 knots.