CEN23FA174

After takeoff, the flight proceeded toward the intended destination airport. Position data initially depicted the airplane about 0.75 miles from the departure airport at 6,000 ft mean sea level. The final data point was recorded about 10 minutes later when the airplane was about 15 miles from the departure airport at an altitude of 9,400 ft msl. This was about 0.20 miles from the accident site. The pilot’s family informed local authorities that the flight was overdue, and the accident site was located the following morning. The accident site was in mountainous terrain an elevation of about 9,170 ft. Terrain in the immediate vicinity of the accident site rose to nearly 9,300 ft. The airplane came to rest inverted after impacting trees and terrain. A postimpact fire consumed most of the fuselage. Postaccident examinations did not reveal any anomalies attributable to a preimpact failure or malfunction. The accident flight likely encountered moderate mountain wave turbulence with downdrafts as strong as 500 ft per minute (fpm) and updrafts as strong as 1,000 fpm at the time of the accident. The weather conditions encountered were consistent with the National Weather Service G-AIRMET forecast. It is unknown what weather information the pilot received before or during the flight. The expected climb performance at maximum gross weight and a pressure altitude of 10,000 ft was 450 fpm. This was about one-half of the expected climb rate at sea level. The estimated density altitude at the accident site was about 11,300 ft. Advisory information regarding mountain flying provided by the Federal Aviation Administration suggested maintaining at least 1,000 ft terrain clearance when navigating a mountain pass or crossing a ridge line. However, if the wind is above 20 knots, the suggested terrain clearance increased to 2,000 ft to avoid most of the turbulence and downdrafts. As the airplane approached a mountain ridge line with about 100 ft altitude clearance, the pilot likely encountered previously forecasted moderate turbulence that exceeded the airplane’s climb capability at the elevated density altitude, resulting in an impact with trees and terrain.

The expected climb performance for the airplane at maximum gross weight and a pressure altitude of 10,000 ft was 450 fpm with the engine at full throttle. At 12,500 ft pressure altitude, the expected climb rate decreased to 330 fpm. This was about one-half to one-third the expected climb rate at sea level. The FAA publication Tips on Mountain Flying (FAA-P-8740-60) suggested maintaining at least 1,000 ft terrain clearance when navigating a mountain pass or crossing a ridge line. If the wind is above 20 knots is the guidance recommended pilots increase terrain clearance to 2,000 ft to avoid most of the turbulence and downdrafts. The information also noted that at higher density altitudes, the airplane’s rate of climb and actual service ceiling are decreased. According to Federal Aviation Administration (FAA) records, the airplane was assembled from spare parts and certificated in the experimental-exhibition category in April 2012. The airplane was originally manufactured as a Cessna model R-172E and sold to the U.S. Army as a model T-41B. The owner informed the FAA that he did not know the disposition of the military data plate, nor did he have any military records for the airplane. On May 6, 2023, about 0935 mountain daylight time, an experimental Pool-Cessna R-172E (T-41B) airplane, N15188, was destroyed when it was involved in an accident near Victor, Colorado. The pilot and 3 passengers were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the airport manager, the flight departed the Freemont County Airport (1V6), Canon City, Colorado, about 0920, with an intended destination of Centennial Airport (APA), Centennial, Colorado. Later in the day, the pilot’s family notified local authorities that the flight was overdue. The accident site was subsequently located the following morning. Airplane position data revealed that after takeoff, the flight proceeded north. The initial data point was recorded at 0924:54 and located about 0.75 miles northwest of 1V6. The altitude associated with that data point was 6,000 ft mean sea level (msl). The final data point was recorded at 0934:57 and located about 0.20 miles south of the accident site. The altitude associated with that data point was 9,400 ft msl. The accident site was in mountainous terrain about 15 miles north of the departure airport at an elevation of about 9,170 ft. Terrain in the immediate vicinity of the accident site rose to nearly 9,300 ft. An autopsy of the pilot was performed by the El Paso County Coroner’s Office. According to the autopsy report, the cause of death was blunt force and thermal injuries, and the manner of death was accident. The FAA Forensic Sciences Laboratory performed toxicological testing on muscle tissue specimens from the pilot. The testing identified acetaminophen and salicylic acid (aspirin), neither of which are considered impairing. No other drugs were detected. Ethanol was not detected.A trough was located immediately west of the accident site with winds at or near perpendicular to the mountain chain. The wind flow near the mountain top was about 25 knots, and about 50 knots near 18,000 ft. A High-Resolution Rapid Refresh (HRRR) sounding indicated up to 600 ft/min updrafts and downdrafts were possible across the area above 14,000 ft. However, pilot reports (PIREPs) indicated that the mountain wave activity, low-level wind shear (LLWS), and turbulence were occurring below 14,000 ft, as well. The PIREPs surrounding the accident timeframe indicated downdrafts as strong as 500 ft/min and updrafts as strong as 1,000 ft/min between 9,000 and 17,000 ft. Low-level water vapor imagery with transverse or gravity wave banding along the mountainous terrain and to points of the Front Range confirmed mountain wave activity. The weather forecast applicable for the accident time indicated that both text and the National Weather Service G-AIRMET Tango for moderate turbulence conditions below 18,000 ft were valid and conditions were confirmed by numerous PIREPs along the Front Range. The estimated density altitude at the accident site was about 11,300 feet. There was no record of the pilot requesting weather information from Leidos Flight Service, nor was there any record of the pilot having an account with ForeFlight. The investigation could not determine what weather information, if any, the pilot received before or during the flight. The airplane came to rest inverted after impacting trees and terrain. A postimpact fire ensued that consumed the majority of the fuselage. The left wing was located with the fuselage. The outboard portion of the right wing was separated near the root and suspended in a tree about 35 ft southeast of the main wreckage. The inboard portion of the right wing was located with the fuselage. The empennage exhibited impact and fire damage. The flight control surfaces remained attached to the airframe. The control surfaces and cables exhibited damage consistent with impact forces and the postimpact fire. No anomalies attributable to a preimpact failure or malfunction were observed. The engine exhibited damage consistent with both the impact sequence and the postimpact fire. No anomalies attributable to an inability to produce rated power were observed.