WPR24FA195

The pilot’s decision to continue low-altitude flight toward rising mountainous terrain in high density altitude conditions, which resulted in collision with trees and terrain.

The pilot and passenger were conducting a cross-country flight in the 65-horsepower, tailwheel equipped airplane to an airport located in mountainous terrain. In-flight photos taken by the passenger showed the airplane at low altitude over the mountains, heading toward higher terrain, about 1/2 mile from the accident site. Accident site signatures were consistent with a collision with trees and subsequent impact with terrain. Examination of the wreckage revealed no evidence of preaccident mechanical malfunctions or failures that would have precluded normal operation. The calculated density altitude at the accident site was about 11,329 ft. Review of the Koch chart using the estimated conditions present at the accident site showed about an 80% decrease in the airplane’s published climb performance under these conditions, which would have resulted in a rate of climb of about 150 ft per minute. The circumstances of the accident are consistent with the pilot’s decision to conduct low-altitude flight into mountainous terrain under density altitude conditions that significantly degraded the airplane’s performance, which resulted in impact with trees and terrain.

The pilot operating handbook for the accident airplane stated in part that, at maximum gross weight, at sea level, the airplane’s rate of climb was 800 ft per minute. Using reported weather conditions and the accident site pressure altitude elevation, review of a Koch Chart showed an 80% (650 ft per minute) decrease in the airplane’s published climb rate. An autopsy of the pilot was performed by the El Dorado County Coroner Unit. According to the autopsy report, the cause of death was blunt force trauma with thoracic injuries (instantaneous). Toxicology testing performed at the FAA Forensic Sciences Laboratory found no drugs of abuse. On June 12, 2024, at 1525 Pacific daylight time, a Luscombe 8A airplane, N37081, was substantially damaged when it was involved in an accident near South Lake Tahoe, California. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The airplane was the subject of an alert notice (ALNOT) issued by the Federal Aviation Administration when the pilot and passenger did not arrive at their intended destination of Lake Tahoe Airport (TVL), South Lake Tahoe, California. Family members reported that they had spoken to the pilot earlier in the day and the pilot indicated that they were running late and would be arriving at TVL around 1530. The airplane was located by local law enforcement the following morning in the Humboldt-Toiyabe National Forest at 8,000 ft mean sea level (msl), about 10 miles southeast of TVL. There were no known witnesses to the accident sequence. In-flight photos and their GPS locations were provided by the family of the passenger. Three of the provided photos were captured about 1/2 mile southwest of the accident site and showed the airplane at a low altitude over mountainous terrain, with a heading oriented toward rising terrain (see figure). Figure: Plot of photos in relation to the accident site and destination airport. The airplane came to rest inverted in a clearing on a magnetic heading of 333° about 75 yards from a service road. The first identified point of contact was a 75-ft tall tree that was missing limbs and a portion of the tree trunk, which were located within the debris path. Also in the debris path, about 25 ft from the initial tree strike, was a portion of the empennage and tail section that was lodged in the top of an approximate 15-ft-tall tree. The main wreckage was located about 10 ft beyond that tree. All major structural components of the airplane were located throughout the wreckage debris path.  Postaccident examination of the recovered wreckage revealed that flight control continuity was established from the cockpit controls to all primary flight controls. Rotational continuity was established throughout the engine and valvetrain. Thumb compression was obtained on all four cylinders. Examination of the recovered wreckage revealed no evidence of preaccident mechanical malfunction or failure that would have precluded normal operation. The calculated pressure altitude for the accident site was 7,788 ft msl, and the calculated density altitude was 11,329 ft msl.