On September 20, 2004, at 1535 Pacific daylight time, a Piper PA-28-181, N43779, sustained substantial damage while taxiing for takeoff at the Boeing Field/King County International Airport (BFI), Seattle, Washington. The airplane is registered to Wings Aircraft LLC of Snohomish, Washington, and operated by Puget Sound Aviators of Seattle, Washington. The private pilot, sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the planned personal flight, which was to be operated in accordance with 14 CFR Part 91, and a flight plan was not filed. The flight was originating at the time of the accident. According to the Pilot/Operator Aircraft Accident Report (NTSB form 6120.1/2), the pilot reported that he was not familiar with the area where his airplane was parked. After reviewing the airport diagram and taxiways, he noted that taxiway Bravo 8 (B8) at BFI was a marked entrance to the taxiway [taxiway B]. The pilot stated that as he was unfamiliar with other taxiway entrances (unmarked entrances), he chose to maneuver through the parking area to request entrance to [the] taxiway [at] B8. The pilot further stated that he turned left out of his parking area and proceeded north toward B8, but "...noted another aircraft parked close to my left leading edge." The pilot reported that as he approached to pass the other airplane he applied braking, being concerned that he had misjudged his clearance. The pilot stated, "In doing so I applied too much left brake, striking my left wing's leading edge with the parked aircraft." A post accident examination revealed that the outboard section of the left wing had sustained structural damage.