On September 11, 1999, approximately 1700 Pacific daylight time, a Gentry Series 5 Vixen amateur-built experimental-category airplane, N199DG, collided with terrain near Naples, Idaho. The airplane was destroyed by impact forces and a post-crash fire, and both occupants (both of whom were private pilots) were fatally injured in the crash. The accident occurred while the airplane was operating from a landing surface on the aircraft owner's property. No flight plan had been filed for the 14 CFR 91 personal flight, which according to a witness was bound for Bonners Ferry, Idaho. Visual meteorological conditions were reported at Coeur d'Alene, Idaho, approximately 54 nautical miles south of Naples, at 1655. The aircraft occupants were brothers flying an airplane registered to their father. A witness, a third brother, reported that the purpose of the accident flight was to familiarize one of the brothers (a private pilot with approximately 150 hours total pilot time, according to the witness) with the aircraft, and that the other brother aboard the aircraft (a private pilot with approximately 1,000 hours total pilot time and a tailwheel aircraft endorsement, according to the witness) was pilot-in-command of the accident flight. The witness reported that immediately after taking off, the airplane started a 180-degree turn back to the landing surface, and approached the landing surface in the opposite direction. The witness stated to an FAA inspector that "The aircraft descended to within a few feet (2-4), approximately mid field, appeared to be moving too fast to land and then initiated what he thought was a go around with a takeoff to the northwest." It then made a second 180-degree turn back in the direction of the landing surface. The witness reported that during the second 180-degree turn, the aircraft abruptly entered a descent and crashed. The witness reported that a fire erupted after ground impact. According to FAA records, the airplane received original experimental-category airworthiness certification on October 25, 1996, and the aircraft was registered to its current owner in August 1998. The aircraft log indicated that the aircraft received its most recent condition inspection on February 10, 1999, at 178 tachometer hours, and that the aircraft had 224.8 hours at the time of its most recent logbook entry (various repairs) made on July 11, 1999. The aircraft, originally built with tricycle landing gear, was converted to a tailwheel landing gear configuration after the present owner purchased it. The aircraft was powered by a converted Subaru EA81 automotive engine manufactured by NSI Propulsion Systems, LLC, of Arlington, Washington. An FAA inspector from the Spokane, Washington, Flight Standards District Office (FSDO) responded to the accident scene and performed an on-site examination. The FAA inspector reported finding a section of barbed wire underneath the wing of the aircraft at the crash site, as well as underneath the propeller hub in the dirt. The FAA inspector reported the sections of barbed wire found at the accident site displayed shiny breaks and scars, and that the crash site was not near any fences. The FAA inspector also reported finding two identical nicks on two of three propeller blades (he reported the third blade had been melted in the post-crash fire), which generally matched the dimensions of the barbed wire found at the site, and that he observed no other leading edge damage to the propeller. The FAA inspector reported that there are fences at each end of the landing surface, but that he did not find any damage or missing wire to those fences. The FAA inspector reported he found no evidence of any pre-crash problems with the aircraft's engine or flight controls during his on-scene examination. Autopsies on both pilots were conducted by The Forensic Institute at Holy Family Hospital, Spokane, Washington, on September 13, 1999. The cause of the pilot-in-commands's death was determined to be "aortic laceration due to blunt impact injuries, presumably, to the lower torso with transference of energy." The autopsy report on the pilot-in-command stated: "The autopsy did not reveal any health condition that would have precluded this party from operating as pilot in command of a private aircraft." The cause of the second pilot's death was determined to be "blunt impact injury to the chest, resulting in cardiac and aortic lacerations." The second pilot's autopsy report stated: "To the extent that the investigation of this crash may consider the health status of this individual, with regard to his capacity to operate as pilot in command, it should be noted that no significant intrinsic disease state which might have compromised his ability to perform that function was identified." Toxicology testing on both pilots was conducted by the FAA Civil Aeromedical Institute (CAMI), Oklahoma City, Oklahoma. The CAMI toxicology tests screened for carbon monoxide, cyanide, ethanol, and drugs in both pilots and detected none in either pilot.