On May 9, 2013 about 1630 Pacific daylight time, a Schweizer, G-164B, bi-wing, tail-wheel airplane, N8214S, collided with runway service equipment during the landing roll at the William's Ag Services airstrip, Biggs, California. The pilot was not injured; the operator of the service equipment was fatally injured. The airplane, which sustained minor damage, was registered to Clarence E. Williams, and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91, as a post-maintenance repositioning flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Yuba County Airport, Marysville, California about 1615. The pilot reported in a written statement to the National Transportation Safety Board investigator-in-charge that he entered the traffic pattern on an angled downwind approach, then descended down to 500 feet above ground level. He announced his intentions to land and was told by Williams Ag Services operations that maintenance was being performed on the south end of the runway. The pilot scanned the area and saw trucks parked on the south end of the airstrip property. He further stated he observed nothing on the runway. The pilot landed mid-field on runway 18 and started performing S-turns due to restricted front view of the tailwheel airplane while taxiing. Soon thereafter, he felt the collision, immediately applied the brakes and came to a stop on the runway. The flight was uneventful, up until the collision. The operator of the service equipment was part of a maintenance crew repairing the runway. No other personnel were in the area at the time of the accident. The operator was pushing an 8 horsepower blower down the center of the runway and was wearing hearing protection. An examination of the airplane by a Federal Aviation Administration inspector revealed minor damage to both the inlet scoop and the lower right wing lower surface.