At about 0920 eastern time, a Cessna 172S collided with a parked airplane while taxiing at the Melbourne Regional Airport. The student pilot was not injured. The pilot said he received his taxi clearance and released the parking brake. The airplane began to roll forward and he applied the airplanes brakes to perform a brake check, but the brakes were ineffective. The airplane rolled forward and collided with a parked twin. Several witnesses said they heard the engine operating at high power before the impact.