On July 12, 1993, at approximately 1253 hours mountain daylight time (MDT), a Piper PA-32-260, N3774W, registered to and being flown by Robert R. Vignaroli, a certificated private pilot, sustained substantial damage during a forced landing following a total loss of power while in cruise near Arlington, Wyoming. The pilot and his wife sustained serious and minor injuries respectively. Visual meteorological conditions prevailed at the time and a VFR flight plan had been filed for the trip from Denver to Jackson, Wyoming. The flight, which was personal in nature, was to have been operated in accordance with the requirements set forth in 14CFR91. The pilot reported that he made an intermediate stop at Laramie, Wyoming, during which the aircraft was fueled (topped off), and then departed for Jackson at approximately 1240 hours. Shortly after levelling off, a slow loss of power developed which the pilot was unable to eliminate. He then decided to execute a forced landing. The pilot stated that during the flare to land he "was a little high causing initial impact at near stall speed, removing main gear." The aircraft's fuel system was examined at the facilities of Beegle Aviation, in Greeley, Colorado. The fuel selector valve was examined and found to contain contaminated water in the sump bowl. Additionally, the drain lever was rusted in the "closed" position. Additionally, the aircraft's auxiliary fuel pump was functionally checked and found to be operational. However, the pump's filter was observed to be covered with a rust colored substance. The last inspection conducted on N3774W was on March 30, 1992. This inspection was logged as an "annual" at a tach/total time of 4676.8 hours. The tach time at the accident was approximately 4740.7 hours (63.9 hours elapsed between March 30, 1992, and July 12, 1993). FAA Airworthiness Directive 77-12-01 requires in part, that this particular PA-32-260 be subjected to a fuel selector valve procedural check a minimum of at least every 50 hours so as to "prevent a fuel system malfunction and a possible power interruption." The AD was signed off as having been accomplished on March 30, 1992, however, there was no further airframe log entries addressing the AD subsequent to that time. Additionally, the Piper Cherokee Six Service Manual, (revised 11/04/83) states in its inspection procedures to "Remove, drain, and clean fuel strainer bowl and screen located in bottom of fuel selector (Drain and clean at least every 90 days)" refer to Report of Fred W. Ohrn, FAA Inspector.