On May 27, 1998, about 1410 Alaska daylight time, a wheel equipped Luscombe 8A airplane, N1322B, sustained substantial damage during an emergency landing on a highway, about 5 miles south of Paxson, Alaska. The airplane was being operated as a visual flight rules (VFR) personal flight under Title 14 CFR Part 91 when the accident occurred. The certificated airline transport pilot, and the one passenger aboard, were not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated at the Cantwell Airport, Cantwell, at 1230. During a telephone conversation with the National Transportation Safety Board investigator-in-charge, on May 28, at 1015, the pilot reported that while in cruise flight, the engine began to run rough. The pilot said he attempted to divert to the Paxson Airport for landing, but the airplane's engine continued to lose power, and the airplane was no longer able to maintain altitude. The pilot selected a portion of the Richardson Highway as an emergency landing area. During the landing roll, the right wing struck an overhanging tree, and the airplane turned to the right and struck an embankment. The airplane sustained substantial damage to the wings and fuselage. The pilot noted in his written statement dated June 6, that a broken intake valve was discovered on the number 3 cylinder during a postaccident engine examination.