On August 20, 2002, at 1045 mountain daylight time, a Hildebrandt Rutan Defiant, N219DF, was substantially damaged when it collided with terrain during a rejected takeoff at Erie Airpark, Erie, Colorado. The private pilot and one passenger were not injured. Day visual meteorological conditions prevailed, and no flight plan had been filed for the personal flight being conducted under Title 14 CFR Part 91. The flight was originating at the time of the accident. The following is based on a telephone interview with the pilot shortly after the accident, and the accident report he submitted. The pilot was taking off on runway 15. Power was applied to the rear engine, followed by power application to the forward engine. The airplane accelerated "slower than usual" and when the airplane was halfway down the runway, he elected to reject the takeoff. The pilot said he "couldn't rotate the airplane...it seemed to require more back pressure...it didn't seem right." He retarded power to both engines to idle and applied brakes. "The brakes seemed to grab at first, but then had no effect," he wrote. The pilot retarded the mixtures. The airplane went off the end of the runway and traveled 500 feet across rough terrain, collapsing the nose landing gear and bending the fairing. According to an FAA inspector who examined the airplane, the "Rhino" rudder and the engine cowling were crushed and the propeller was bent. The pilot said the fixed base operator's mechanic found a dowel from the left wheel pant about halfway down the runway. "I believe this may have contributed to my slower than usual takeoff roll. The calipers and linings on the brakes were fresh, I had just had them rebuilt/replaced," the pilot wrote.