On March 11, 2005, at 1800 Pacific standard time, a Jeffs J-Bird amateur-built airplane, N6407M, sustained substantial damage when it impacted terrain following a loss of control while maneuvering in the valley of the Willamette River about 6 miles south of St. Paul, Oregon. The private pilot and the passenger were not injured. The personal flight was being operated by the pilot under 14 CFR Part 91. Visual meteorological conditions prevailed and no flight plan was filed. The local flight departed from Chehalem Airpark in Newberg, Oregon about 1730. The pilot reported that he was maneuvering at "slow airspeed, low altitude" in the river valley. He further reported that the left wing stalled during a left turn. The airplane descended, impacted willow trees, and came to rest on a gravel bar. An FAA inspector examined the airplane and reported that the fuselage, both wings and the empennage sustained structural damage.