On November 28, 1995, about 0923 eastern standard time, a Cessna 414, N200DC, was substantially damaged during an aborted takeoff from the Hardwick Field Airport, Cleveland, Tennessee. Instrument meteorological conditions prevailed at the time and an IFR flight plan was filed for the 14 CFR Part 91 business flight. The commercial-rated pilot was not injured and four passengers sustained minor injuries. One passenger was seriously injured. The flight was originating at the time of the accident. Before departure at the request of the pilot, each tip tank was filled and the line service employee examined the left wing locker fuel tank to determine fuel capacity. He reported to the pilot that it appeared to be about 1/2 full. The total capacity of each wing locker tank is 20 1/2 gallons of which 1/2 gallon is unusable. The pilot stated to one of the passengers before takeoff that the airplane fuel quantity before fueling was 126 gallons; and 40.4 gallons of fuel were added before takeoff which filled each tip tank. Each tip tank has a capacity of 51 gallons, of which 50 gallons are usable. The passengers boarded the airplane which was observed by the line service employee to taxi toward runway 03. The employee who is also a certified flight instructor (CFI) suggested the pilot takeoff from runway 21 due to the upsloping condition when using runway 3. The pilot stated he then taxied to runway 21 and performed a run-up of each engine then applied full power to both engines while the brakes were applied. The pilot then released the brakes and about 1/2 way down the 3,300-foot downsloping wet asphalt runway, he aborted the takeoff due to inadequate acceleration. The airplane started hydroplaning and continued off the end of runway onto grass. With a 15-foot drop off ahead the pilot applied full power to both engines which responded. The airplane touched down in a cow pasture, collided with a fence then a concrete culvert before coming to rest upright. All occupants exited the airplane unaided and the airplane was damaged by a postcrash fire. According to a multiengine-rated pilot who has about 16,000 total multiengine flight hours, the airplane appeared to be accelerating slowly during the ground roll to takeoff. He also stated that both engines sounded as if they were developing full power and he did not hear any "missing or sputtering" from either engine. All passengers did not report any change in engine sound from the time full power was applied with the brakes held until the point when the pilot reduced the throttles to abort the takeoff. Postaccident examination of the airplane by FAA inspectors revealed that each tip tank was separated from the airplane. The left wing auxiliary fuel tank was found to be full and the left wing locker tank was observed to be empty. Leakage from the right auxiliary fuel tank was noted and the tank was observed to be about 1/2 full. The right wing locker tank was observed to be full. A fuel tank located in the right wing baggage compartment area was observed to be empty. During recovery of the airplane 19 gallons of fuel were drained from the left wing auxiliary fuel tank which has a total capacity of 20.5 gallons, of which 20 gallons are usable. Additionally, 8 gallons of fuel were siphoned from the right wing locker tank. Weight calculations performed by the pilot indicated that the airplane was 3 pounds over maximum certificated gross weight at the time of takeoff. Postaccident weight calculations indicate that the airplane was a minimum of 359 pounds over gross weight. The calculations are based on an empty weight of the airplane of 4,445 pounds as provided by the pilot, 49 pounds for oil, 1,441 pounds for the passengers and their baggage as provided by the passengers. Additionally, 600 pounds of total usable fuel in both tip tanks, 114 pounds of fuel drained from the left auxiliary fuel tank and 48 pounds of fuel drained from the right auxiliary fuel tank during recovery of the airplane. The certificated gross weight of the airplane is 6,350 pounds. Weight calculations including the above information as well as the observations made by the line service employee regarding fuel quantity in the left wing locker tank, the FAA inspectors regarding fuel observed in the right wing auxiliary and locker tanks indicate that the airplane was about 551 pounds over gross.