Loss of engine power (partial) : Curtiss P-40E Warhawk, N4420K, fatal accident occurred on June 27, 2023, near Ravelli County Airport (KHRF), Hamilton, Montana

• Location: Hamilton, Montana 
• Accident Number: WPR23FA244 
• Date & Time: June 27, 2023, 07:59 Local 
• Registration: N4420K 
• Aircraft: Curtiss Wright P-40E 
• Aircraft Damage: Substantial 
• Defining Event: Loss of engine power (partial) 
• Injuries: 1 Fatal 
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192470/pdf

https://data.ntsb.gov/Docket?ProjectID=192470

On June 27, 2023, about 0759 mountain daylight time, a Curtiss Wright P-40E, N4420K, was substantially damaged when it was involved in an accident near Hamilton, Montana. The pilot was fatally injured, and the airplane sustained substantial damage. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. 

Witnesses reported that the airplane departed from runway 35 after a successful runup. During the initial climb, multiple witnesses reported that they heard a loss of engine power and saw the airplane make a left turn before it descended and impacted terrain.

Postaccident examination of the airplane and engine did not reveal any preimpact mechanical anomalies. Flight control continuity was established from the cockpit control to each flight control surface. The crankshaft was manually rotated by the reduction gear and mechanical continuity of the engine was established throughout the rotating group, valvetrain, and accessory section. Though mechanical continuity was established, the engine could not be placed on the test stand due to impact and thermal damage. Damage to the propeller blades indicated they were under low to no power at impact.

The pilot's postmortem toxicological testing detected Citalopram, a prescription medication commonly used to treat depression and anxiety, However, according to a Federal Aviation Administration medical review, the pilot received multiple renewal letters, medication follow-up checklists, and reports of formal evaluations of his medical conditions within the pilot's medical certification file, indicative of successful management of his condition from 2014 to 2023. Based on the pilot's medical history, he was likely not impaired by his condition; witnesses reported that the pilot was in a good mood during the preflight.

The pilot was likely attempting to make a forced landing to a field about 1/2 mile from the departure airport. The airplane appeared to hit hard on the nose/engine in a nearly wings-level attitude and skidded about 216 ft. Based on the available information, the reason for an engine loss of power could not be determined.

- Probable Cause: A loss of engine power for undetermined reasons.