On March 4, 2000, about 1700 eastern standard time, an Ercoupe 415-C, N3719H, was substantially damaged during a forced landing at Griffiss Airpark, Rome, New York. The certificated commercial pilot and passenger were not injured. Visual meteorological condition prevailed for the personal flight that departed Utica, New York, destined for Griffiss. No flight plan was filed, and the flight was conducted under 14 CFR Part 91. According to the pilot, they had departed Utica and flown to Griffiss to conduct some touch-and-go landings. The weather was "excellent VFR" with the winds from the northeast approximately 12 knots. The first touch-and-go to runway 33 was completed without incident. On the second touch-and-go, at 300 feet agl, the pilot inadvertently selected the mixture control to off instead of carburetor heat. The pilot realized the error, but elected to continue the approach without trying to restart the engine because of altitude remaining. The airplane then developed a "high" rate of descent. With insufficient time and altitude to regain "adequate" airspeed, the pilot unsuccessfully attempted to flare the airplane for touchdown. The airplane impacted the runway approximately 10 degrees nose down, and 50 knots. The pilot secured the airplane's systems. Then, both he and his passenger exited. The pilot weighted 175 pounds, his passenger weighted 190 pounds, and there were 8 to 10 gallons of fuel onboard at the time of the accident. The pilot added that he had not flown the airplane at these "higher weights" in a long time. The pilot contributed the accident to improper selection of the mixture control to off, "airspeed management," "wind gradient awareness," "descent rate awareness," and loss of elevator authority at "low" airspeed.