On August 10, 1999, approximately 1300 mountain daylight time, a Cessna 152, N89186, owned and operated by Buzzard Air, Inc., was substantially damaged when it collided with a bird while on landing approach at Salt Lake City, Utah. The airline transport rated pilot, the sole occupant aboard, was not injured. Visual meteorological conditions prevailed for the aerial observation flight being conducted under Title 14 CFR Part 91, and no flight plan had been filed. The flight originated at Bountiful, Utah, approximately 1255. According to the pilot's accident report, he had been cleared to enter the class B airspace surrounding Salt Lake City International Airport, and was southbound over Interstate Highway 15 at 5,500 feet msl (mean sea level). When he was about 3 miles northeast of the airport, he noticed an eagle soaring at his altitude and at his 1 o'clock position. As the eagle drew closer, the pilot made an evasive turn to the left, but the eagle struck the right wing about 18 inches inboard of the wing tip. The airplane landed on runway 32 without further incident. Postaccident inspection by an FAA airworthiness inspector disclosed wing spar damage.