On April 1, 2011, about 1020 Pacific daylight time, an Eagle DW-1, N8812A, collided with a propane truck near Newman, California. West Side Aerial Applications LLC was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 137. The commercial pilot sustained serious injuries. The airplane sustained substantial damage to both lower wings from impact forces. The local aerial application flight departed a private dirt strip near Newman about 1000. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot stated that he was applying his fifth load of the day, and was on the third pass of that load. He was flying over the field, and approaching power lines and a road that split the field. He normally flew about 3 feet above the crop, which was 3-foot-tall wheat. The power lines were about 35 to 40 feet above ground level (agl). He had been flying under the lines unless a power pole obstructed the airplane’s flight path, or he observed traffic on the road, which was fairly busy. As the airplane approached the road, the pilot noticed a propane truck at the last second that was approaching his flight path from his right to left. He tried to adjust, but could not clear the truck. The left main landing gear separated after it collided with the top of the truck. The pilot was able to maintain control of the airplane, so he returned to his nearby home dirt strip. The pilot chose to land the airplane in the soft dirt next to the strip, and was not wearing his shoulder harness. During the abrupt deceleration due to the separated landing gear, his head was thrown forward into the instrument panel, which knocked him unconscious. He was wearing a helmet, but sustained serious injuries to his head. The driver of the propane truck was not injured.