On May 17, 1993, at about 1150 hours Pacific daylight time, a Piper PA 34 200, N410DS, landed hard during the termination of a precautionary landing at Jean, Nevada. The pilot performed the precautionary landing because of a loose engine cowling fastener. The airplane sustained substantial damage. The certificated private pilot and his five passengers were not injured. The pilot rented the airplane for the cross country, personal flight from the operator, Air Desert Pacific of La Verne, California. The flight departed Las Vegas, Nevada, at 1120 hours PDT, and was destined for La Verne. Visual meteorological conditions prevailed and a flight plan was not filed. The pilot was interviewed by an FAA safety inspector. He told the safety inspector that he was southbound in cruise flight at 8,500 feet mean sea level when he noticed the left engine front inboard cowl fastener was loose. The pilot contacted FAA Las Vegas departure control and requested directions to the nearest airport to perform a precautionary landing. Las Vegas departure control advised the pilot that Jean, Nevada, was to the left of his current position. The aircraft landed hard on runway 02 at Jean. The airplane's main landing gear was sheared off and the nose landing gear collapsed. The winds at the time were estimated to be from 020 degrees at 15 knots with gusts to 20 knots. The pilot had trained for and received his multiengine certificate all within the past 90 days prior to the accident. He reported a total multiengine time of 19 hours with 8 hours of that as pilot in command. The pilot reported a total flight time of 331 hours.