After touchdown, the airplane veered off the right side of the runway and collided with a vehicle. During the collision sequence, the airplane spun 180 degrees and its right main landing gear collapsed. The pilot said that following the airplane's touchdown on the runway, he started to apply the brakes but they felt mushy and unresponsive. He applied more and more pressure to the brakes but the airplane did not stop. As he continued to apply pressure, the airplane departed the right side of the runway and collided with a vehicle. A Federal Aviation Administration (FAA) airworthiness inspector examined the braking system with an aviation maintenance technician. The left brake had new linings and the brake disk was worn. The right brake linings were at a minimum and the disk was within acceptable limits. Responding law enforcement officers noted that three distinctive skid marks matching the dimensional geometry of the aircraft's landing gear were on the runway and they veered for several hundred feet off the right side of the runway and led to the impact damaged vehicle and the airplane. The skid marks corresponding to the right and left main wheels were identical in width, heaviness, and color. The FAA inspector reported that there was no evidence that either brakes had locked up during the landing.