On June 21, 2005, about 1450 central daylight time, an experimental exhibition S A Aerostar S C, N962KY, piloted by a private pilot, sustained substantial damage on impact with a ditch during a forced landing following an in-flight loss of engine power on approach to the Columbus Municipal Airport (OLU), near Columbus, Nebraska. The personal flight was operating under 14 CFR Part 91. Visual meteorological conditions prevailed at the time of the accident. No flight plan was on file. The pilot sustained minor injuries. The local flight departed OLU about 1415. The pilot's accident report stated: At approximately 2:15 PM, I ... departed OLU (Columbus, NE) in a YAK 52, N962KY. After about 35 minutes of routine practice, I proceeded back to OLU and entered the pattern midfield (from the West). I performed a touch and go, then proceeded to the South East to let the system air pressure rejuvenate. I, then proceeded directly to the airport at 2500 feet [above mean sea level] for a 45 degree entry. I, then checked all systems, CHT, fuel pressure, oil pressure, oil temp, fuel. All systems were within parameters, including fuel, which was 12 in the left tank and 30 in the right tank. Approximately 2 to 2 1/2 miles East of the airport the engine lost power. There was no warning. I, immediately, established best glide, radioed Mayday on 122.95 (the airport Unicom) with approximate location. I proceeded to once again check all systems and scanned for emergency landing area options. I deckled there was a possibility of making the grass strip (20). YAK 52's having a glide ratio of a brick. I soon realized that I was not going to have the altitude to make the grass. Again, looking for alternative emergency landing areas, my choices were very limited to a gravel road, which had no small power lines crossing it. It became apparent that I could not reach the gravel road without clearing the top of a large set of power lines. I then elected to go under the large power lines. Leaving the gear retracted, I, set down in a cornfield. Unfortunately, momentum took me about 20 yards too far to a road ditch. At which point the aircraft impacted one side then the other side of the ditch before coming to a full stop. Fortunately the aircraft remained upright and straight. No loss of power was noticed at any time during the flight. No warning lights, no rough running, no fumes, no smells, absolutely no indications or warnings of a problem. Approximate time from loss of power to impact was about 25 seconds. I am currently at a loss as to what caused the loss of power. I suspect some type of fuel starvation problem. A Federal Aviation Administration inspector performed an on-scene examination of the wreckage. The inspector used the assistance of an inspection authorized airframe and powerplant mechanic during the examination. The mechanic stated: Upon my arrival at the Columbus, Nebraska airport at 8:00 AM on 6/27/05, we moved aircraft YAK 52 (N962KY), located at Columbus, Nebraska, from the storage hangar to the maintenance hangar. The main purpose for this report is to determine why the fuel remaining in the right fuel tank didn't drain into header tank and feed fuel to the engine. A total of 11 1/2 gallons of fuel was drained from the header tank and the right main. The owner did complain of uneven fuel burn between the right and left tanks. We tried to determine why the fuel from the right tank didn't drain using the drain sump. After some discussion, we came to the conclusion that the shuttle valve was stuck. While removing the lines from shuttle valve #526-103-00 we noticed that the right and left hoses to the 3-way valve #526-103-00 had been replaced. The log book shows they were replaced in November of 2004, during the Annual Condition Inspection. Upon the removal of the right hose, we noticed a very small flow rate through the line. After removal of the hose from the aircraft for further inspection, we noticed that the after market hoses were not properly assembled. The interior of the hose on both the tank side and the fuselage side were 90% plugged with interior rubber from the hose.