On January 10, 2011, at 1724 Pacific standard time, N57027, a Ryan Aeronautical ST3KR, collided with a wind sock pole while attempting to land on runway 8 at Warner Springs Gliderport, Warner Springs, California. The airplane sustained substantial damage. The commercial pilot survived the accident but later succumbed to his injuries, and the passenger sustained serious injuries. Visual meteorological conditions prevailed and no flight plan was filed. According to the San Diego County Sheriff's Office responding deputy, the passenger stated that they intended to fly to Borrego Valley Airport, Borrego Springs, California. They diverted to Warner Springs because it was getting dark and weather conditions were deteriorating. While approaching runway 8, the airplane impacted a wind sock pole with the left wing. The pilot, age 87, held a commercial pilot certificate for airplane single and multi-engine land. He held an expired third class medical that was issued on December 1, 2008. It held the limitations that the pilot must wear corrective lenses for near and distant vision. The airport manager reported that the runway does not have pilot-activated runway lights. He indicated that the wind sock was located about 70 yards before the approach end of the runway and 30 yards left of it. The airport is surrounded by mountainous terrain. The US Naval Observatory Astronomical Applications Department reported that sunset was at 1726 and the end of civil twilight occurred at 1759.