On November 7, 1997, approximately 1100 mountain standard time, a Piper PA-22-150 (converted to a PA-20), N9607D, was substantially damaged when it collided with terrain during the takeoff roll at Broomfield, Colorado. The commercial pilot and passenger were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight being conducted under Title 14 CFR Part 91. The flight was originating at the time of the accident. The pilot said he began the takeoff roll and at 25 to 30 mph, he raised the tail. The airplane "immediately jerked to the left." The pilot corrected with right rudder, overshot the runway centerline, and the airplane "jerked to the left" again. The pilot aborted the takeoff but the airplane skidded off the right side of the runway. The right landing gear collapsed and the airplane nosed over. In an interview with the pilot, he said he "over-corrected" and the airplane began "fish tailing." The right wing then contacted the ground as the aircraft swerved to the left and the airplane nosed over. The pilot said he may have inadvertently stepped on a brake, causing the loss of control. Damage was consisted of a collapsed right main landing gear, bent left wing spar, and twisted engine cowling.