On January 29, 1999, at 1601 hours Pacific standard time, a Coelho RV4, N770RF, collided with a Cessna 150L, N6979G, while taxiing for takeoff at the Madera, California, airport. The Cessna 150L was stationary on the parallel taxiway of runway 30 conducting a pre-takeoff engine and systems check. Visual meteorological conditions prevailed at the time. The Cessna 150L was owned and operated by Madera County Aircrafters and rented by the pilot for a local area personal flight. The Coelho RV4 was owned and operated by Rocket Factory, Inc., and was also departing for a local area personal flight. Both aircraft were operated under 14 CFR Part 91 of the Federal Aviation Regulations. The Cessna 150L was destroyed and the Coelho RV4 sustained minor propeller damage. Neither of the pilots, the sole occupants of their respective aircraft, were injured. Both aircraft were originating at the time of the on-ground collision. According to a statement from the pilot of the Cessna 150L, she was stopped on the parallel taxiway waiting for departure behind a C172 and an ultralight aircraft. She reported that the run-up area was congested and she did not believe there was enough room to safely pull into the area. While waiting on the taxiway, the propeller of a RV4 struck the tail section of her aircraft. The pilot of N770RF (a conventional gear airplane) stated that he was performing "S" turns on the parallel taxiway while taxiing out for departure and did not notice the Cessna stopped on the taxiway.