WPR10LA406

During an aerial wildlife observation flight, the wildlife biologist requested that the pilot maneuver the airplane at a lower altitude over a specific location. While in a descending turn, the pilot intentionally entered a left-wing-low slip in an effort to increase the rate of descent. At the end of the turn, the airplane's rate of descent increased significantly, and the pilot was unable to level the wings prior to the left wing impacting terrain. A postaccident examination revealed that there was no evidence of a mechanical malfunction or failure with the airplane.

On August 16, 2010, about 0705 mountain daylight time, a Bellanca 7GCBC, N5034K, impacted the terrain about 10 miles south of Douglas, Wyoming. The commercial pilot and his passenger received serious injuries, and the airplane, which was owned and operated by Laird Flying Service, sustained substantial damage. The local 14 Code of Federal Regulations Part 91 wildlife observation flight, which departed Douglas, Wyoming, about 13 minutes prior to the accident, was being operated in visual meteorological conditions. No flight plan had been filed. According to the Federal Aviation Administration (FAA) inspector who interviewed both the pilot and the passenger, the pilot was maneuvering about 300 feet above ground level (agl) in order for the passenger, a wildlife biologist, to count the number of antelope in a field. Because the passenger needed to get lower in order to more easily make a determination of the age and sex of the antelope, he asked the pilot to descend lower and to make another pass over the field. The pilot then initiated a series of turns, and while still in a turn, began to slip the airplane with the left wing low in an attempt to lose altitude. Near the end of this sequence, the descent rate of the airplane increased significantly, and before the pilot could level the wings and arrest the descent, the airplane's left wing contacted the terrain. After the wing contacted the terrain, the airplane bounced back up into the air, came down almost directly on its nose, and then cartwheeled over. As part of the investigation, the FAA inspector who interviewed the occupants calculated the weight of the airplane at the time of the accident. That calculation determined that at the time of the accident sequence, the airplane was about 239 pounds over Maximum Allowable Gross Weight. An inspection of the airplane's flight control system by the FAA inspector did not find any evidence of flight control anomalies, and according to both the passenger and the pilot, there were no unusual engine noises prior to or during the accident sequence.