On March 7, 2015 about 1230 central standard time, a Rans S-12 homebuilt experimental airplane, N154BH, registered to a private individual, collided with trees and the ground while maneuvering to land after reported engine problems while in the landing pattern at the Cherokee County Airport (JSO), near Rusk, Texas. The pilot and passenger sustained serious injuries and the aircraft was substantially damaged. The local flight was being conducted under the provisions of Federal Code of Regulations Part 91. Visual meteorological conditions prevailed in the area and a flight plan was not filed. According to the FAA, about 2 weeks prior to the accident, the passenger had purchased the ultralight aircraft. The purpose of the flight was to become familiar with the newly acquired aircraft. The PIC had about 11,000 hours of total flight time, with about 2 hours in the accident make and model. The PIC's most recent BFR was conducted on December 9. 2014. According to a written bill of sale, the passenger purchased the airplane on February 19, 2015. The aircraft's most recent conditional inspection was conducted on March 3, 2015. Witnesses reported that the ultralight aircraft was doing touch and go landings at JSO. They reported that the engine did not sound normal and observed the aircraft maneuver toward a field before it stalled, collided with trees and impacted the ground. The pilot and passenger were transported to the hospital after the accident. The FAA traveled to the accident scene and inspected the accident area and wreckage. There was evidence of fuel smell at the accident site. Inspection of the airframe and engine at the accident site did not reveal any abnormalities. The reported weather observation METAR at JSO about the time of the accident was: KJSO 071735Z AUTO 00000KT 10SM BKN100 12/M05 A3048 RMK AO2 T01211051 According to the Icing Probability Chart, with a temperature of 12 degrees and dew point of 5 degrees, the aircraft engine was operating in an area conducive to light icing at cruise of descent power. The NTSB did not receive a NTSB form 6120, Pilot/Operator Report or statements from the pilot and passenger. It is unknown if the passenger/owner had flight experience.