Accident Summary
On April 14, 2008, at approximately 1038 mountain daylight time, an Artic Aircraft Corporation S-1B2 single-engine airplane, registration N73WY, collided with terrain while maneuvering at low altitude near Rock River, Wyoming. The aircraft was owned and operated by TS Aviation of Worland, Wyoming, and was being used for a survey of geese for the Wyoming Department of Game and Fish. The airplane sustained substantial damage. The certificated commercial pilot incurred serious injuries, and the passenger, a biologist employed by the Wyoming Department of Game and Fish, sustained minor injuries. Visual meteorological conditions prevailed, and a company flight plan was filed. The flight had departed Worland at an undetermined time for the survey mission.
Aircraft and Operator
The aircraft was an Artic Aircraft Corporation S-1B2, a single-engine airplane. The operator, TS Aviation, was operating the aircraft under the provisions of 14 CFR Part 91 of the Federal Aviation Regulations. According to the Director of Operations, TS Aviation did not have a 90-day exclusive use contract with the State of Wyoming, and the flight was not a public-use operation.
Pilot and Passenger Accounts
The pilot made consistent statements to law enforcement, medical response personnel, and the company that he had no memory of the accident sequence.
The biologist was interviewed by a Federal Aviation Administration inspector and submitted a written statement. He reported that they had been flying about 100 feet above ground level, following a creek over low rolling terrain, while he observed and counted geese. On previous flights, the pilot had flown too fast for accurate counting, so the biologist had asked him to fly slower. On this flight, the pilot extended the flaps and flew at an estimated speed of 50 to 60 miles per hour. They were following the creek, with the pilot making a right turn and then a left turn. The biologist was looking away when he heard the pilot call out an expletive. When he looked forward, the airplane was in a right-wing and nose-down attitude descending toward the ground. The pilot managed to level the airplane just before impact. The biologist did not hear any change in engine sounds during the sequence and had not heard the pilot express any concerns about the aircraft's handling.
Investigation
The accident occurred near Rock River, Wyoming. The investigation focused on the circumstances of the low-altitude maneuvering flight. No probable cause was stated in the official source.