On June 29, 1997, about 1915 Pacific daylight time, N15TJ, a homebuilt Stiritz Eipper MX II airplane, operated by Digatron, collided with terrain during an uncontrolled descent near Newport, Washington, and was substantially damaged. The descent was precipitated by the structural failure of the right wing while the airplane was maneuvering. The private pilot and his passenger were not injured. Visual meteorological conditions prevailed and no flight plan had been filed. The personal flight departed from Newport and was conducted under 14 CFR 91. In a written statement sent to the Safety Board by the pilot (attached), the pilot stated that he was "giving rides to friends and family" from the Deer Park Airport in Deer Park, Washington. On the final flight, the pilot and passenger climbed to 3,000 feet above the ground and began an intentional "spiraling descent." As the airplane descended to about 1,500 feet above the ground, the right wing "collapsed." The pilot stated that he activated the airplane's ballistic parachute, and the airplane "settled into the tree tops." The ballistic parachute used in the airplane was a Second Chantz Aerosafe 750 Ballistic Parachute System. The pilot further stated: "It appears that the bolt holding the right lower trailing edge cable broke. This is not A.N. hardware. It is a Grade 3 bolt." The pilot also stated that this bolt was different than the bolts holding the "outer leading edge cable." According to a Federal Aviation Administration (FAA) aviation safety inspector from Spokane, Washington, an examination of the main spar failure did not reveal any evidence of corrosion or fatigue. The failure occurred about 5 feet outboard of the wing root. No further examination of the wreckage was performed by the FAA inspector. An examination of the airplane's maintenance records (excerpts attached), revealed that the structure of the airplane was built by the pilot during a three-day period in February 1987. On July 24, 1987, the airplane was issued an experimental airworthiness certificate by the FAA. An entry dated December 2, 1988, was found that stated that the airplane received a condition inspection in accordance with Appendix D of 14 CFR Part 43. No further entries were made in the log book until August 5, 1995, when another condition inspection was noted. The next entry in the log book was also the last entry and was dated August 3, 1996. The entry was signed by the builder/pilot and stated the airplane was "...found to be in a condition of safe operation."