The pilot had received his private pilot certificate about 7 months before the accident. He had told family members that he was planning to fly with his friend, the passenger, and stay in the airport traffic pattern performing touch-and-go takeoffs and landings.Contrary to the pilot's stated plan, radar data indicated that the airplane departed toward a meandering river canyon immediately after takeoff. The radar data ended just before the airplane entered the canyon, likely due to terrain masking along the route of flight as a result of the airplane descending below the canyon walls.The wreckage was located about 2 miles beyond the entrance to the canyon, at a tight turn of the river. The wreckage was on the steep face of a boulder-strewn cut bank about 500 ft above the river and 200 ft below the canyon rim. Wreckage debris indicated that the airplane impacted the ground in a near-vertical attitude with low-energy impact signatures, consistent with a low-speed collision and likely the early stages of a spin. The majority of the primary airframe structure was consumed by fire, but postaccident examination did not reveal any anomalies with the remaining airframe or engine components that would have precluded normal operation.Performance calculations indicated that, while it was theoretically possible to negotiate the canyon bend in the airplane, the pilot would have needed to fly with precision and factor for tailwinds along with turbulence and downdrafts that were likely present in the canyon at that time and would have made escape from the canyon difficult.The pilot had flown through the canyon with his instructor once before in another, slower, airplane but in the opposite direction of flight than that he took on the day of the accident. The wreckage was located in an area the instructor had specifically warned the pilot about due to the tight radius of the river bend and the close canyon walls, and during that flight they had bypassed the area. It is possible that the pilot did not recognize the turn during the accident flight because he was approaching from the opposite direction.Page 2 of 14 WPR17FA213It could not be determined why the pilot chose to fly into the canyon instead of remaining at the airport as he had stated he planned to do. One possibility was that the airplane would soon need refueling, and the exit of the canyon was in the general direction of the airport where the pilot typically purchased fuel. Additionally, although by all accounts the young pilot was a conscientious and conservative aviator, having his friend on board may have influenced his decision to take a more exciting, yet less safe route.There were no witnesses to the accident, and no one realized that the airplane was missing until the day after the accident. The airplane was ultimately discovered a few hours after the search was initiated. Although the airplane was equipped with an operational emergency locator transmitter (ELT), it failed to provide timely notification of the accident for at least two reasons. First, the ELT transmitted on the frequencies (121.5/243 MHz) that are no longer monitored by the Air Force Rescue Coordination Center; instead, they are only monitored randomly by some overflying aircraft. Second, the ELT signal was severely attenuated by the combination of its antenna location in relation to the final resting attitude of the airplane. However, due to the nature of the injuries incurred by both occupants, a timelier response to the accident site would not likely have increased their chances of survival.