On June 27, 2003, approximately 1015 mountain daylight time, an Air Tractor AT-301, N4406S, operated by Frontier Aviation Inc., was substantially damaged when it impacted terrain while conducting aerial application approximately 10 miles east of Glendo, Wyoming. Visual meteorological conditions prevailed, and no flight plan had been filed for the local agricultural flight being conducted under Title 14 CFR Part 137. The commercial pilot reported no injuries. The flight originated at 0930. In his written statement, the pilot said he was performing aerial application at low altitude. The pilot reported that the airplane failed to respond as expected during his pull-up and turn. The pilot said he chose to perform an emergency landing to avoid rising terrain. The airplane struck trees and the terrain. The landing gear failed and the airplane skidded sideways to a stop. An examination of the airplane showed substantial damage to the right wing, undercarriage, and fuselage. Flight control continuity was confirmed. An examination of the engine, engine controls, and other airplane systems revealed no anomalies. Approximately 200 gallons of chemical was recovered from the airplane's hopper. Density altitude at the time of the accident was 6,506 feet mean sea level.