On November 24, 2004, about 1200 central standard time, an amateur-built Spaulding Tailwind W-8, N191AS, sustained substantial damage during a forced landing to a field near Davey, Nebraska, after a loss of power. The private pilot was not injured. The 14 CFR Part 91 personal flight departed Crete Municipal Airport, Crete, Nebraska, on a local flight. Visual meteorological conditions prevailed. No flight plan was filed. The pilot reported that after 20 minutes of flight the engine RPM decreased and there was no oil pressure indication on the oil pressure instrument. The pilot executed a forced landing to a nearby field. During the landing rollout, the landing gear collapsed when the airplane went through a small gulley. The inspection of the engine revealed that an oil hose had blown off one end of the oil cooler. The pilot reported that he had removed the hose during maintenance. When he reinstalled the line on the oil cooler the hose did not get fully attached. He reported, "Evidently when the hose was replaced the end of the nipple stopped at the indentation in the hose caused by the clamp. When the clamp was replaced it was barely over the tip of the hose."