On August 16, 1997, at 1305 eastern daylight time, a Cessna 150L, N16040, was substantially damaged when it collided with terrain after takeoff from the Barnes Municipal Airport, Westfield, Massachusetts. The certificated private pilot and passenger were seriously injured. Visual meteorological conditions prevailed and a flight plan was not filed. The local, personal flight was conducted under 14 CFR Part 91. The pilot reported that he completed a "normal preflight" in preparation to take passengers for orientation flights. He completed a "normal run-up," and during the initial climb the airspeed decreased. He lowered the nose of the airplane and the right wing dropped. The airplane then descended into a cornfield east of the runway. According to the pilot, when he picked up one of the passengers, "...I observed passenger's weight at approximately 200 pounds...Flying at 60-70 knots climb speed, observed immediate rapid decrease in airspeed to 50 knots. Lowered nose, then airspeed increased to 60-70 knots...Experienced loss of lift in the wings with right wing dipping slightly... ." A witness in another airplane waiting to takeoff behind the accident airplane, said that when the accident airplane lifted off the runway, it had a very high pitch attitude. The pitch lowered a little and the left wing lowered. The airplane then descended and landed nose first in the cornfield that was next to the runway, in the opposite direction of takeoff. The pilot was interviewed at the hospital by a Federal Aviation Administration (FAA) Inspector. The FAA Inspector said the pilot reported that the airplane had full fuel, and that he had not completed a weight and balance for the flight. He departed runway 20 from Alpha intersection. FAA calculations of the weight and balance indicated that the airplane had been loaded above its maximum gross weight limit of 1,600 pounds by 156 pounds. The pilot had over 255 hours of total flight experience, which included 30 hours in make and model. Examination of the wreckage did not disclose any evidence of mechanical malfunction with the airplane or engine.