On November 5, 1998, at 1115 hours Pacific standard time, a Dehavilland Tiger Moth DH 82A, N838KC, and a Cessna 152, N68459, collided on a taxiway at the Petaluma, California, airport. The Dehavilland Tiger Moth, operated as a personal flight under 14 CFR Part 91 by the pilot, sustained substantial damage. The Cessna 152, operated as an instructional flight by Aeroventure Clubs, Inc., under 14 CFR Part 91, sustained substantial damage. Neither the private pilot/owner of N838KC, nor his passenger was injured. The student pilot of N68459 was not injured. Visual meteorological conditions existed for the personal flights and no flight plans were filed. The Dehavilland had departed from the Sonoma Valley airport at 1045 and was destined for Petaluma. The Cessna was taxiing to the active runway for departure at the time of the accident. The pilot of N838KC reported that the purpose of the flight was to maintain currency and refuel the airplane. He dialed in Petaluma UNICOM to announce his intentions for landing. After landing, he made a turn off of the runway at the second turnoff. The pilot stated that he did not see any other airplane on the taxiway during the turn. He proceeded to taxi to the refueling station, making "S" turns to watch for traffic. The pilot stated that he did not see the other airplane until he was in a right turn. He reported that he made an unsuccessful attempt to sharpen the turn before the wings collided with each other. The passenger of N838KC stated that he was seated in the front seat, and did not see the other airplane until they collided. In the student pilot's written statement, he reported that he had just refueled N68459, and proceeded towards the taxiway for runway 29. He did not see any other airplanes and continued onto the taxiway. After entering the taxiway he noted another airplane at the far end. He reported that he could not tell what direction it was headed. When he determined that the airplane was moving towards him, he radioed on the UNICOM frequency that he was on the taxiway and was taxiing to runway 29. The student pilot reported that the airplane continued towards him, moving down the center of the taxiway with "very little weaving side to side, about 2-3 [feet] max." The student pilot stated that he stopped about 200 feet away from the taxiway exit. He then radioed N838KC, asking if they could see him, but did not receive a response. He attempted to gain their attention by revving the engine; however, the other airplane continued to taxi towards him. The pilot reported that he attempted to turn off of the taxiway to move out of the way of the oncoming traffic but could not complete the maneuver before the wings of the two airplanes collided. He stated that while in his turn to exit the taxiway he saw the person in the front seat of N838KC turn his head in the direction of the Cessna.