Accident Overview
On July 21, 2025, about 1728 central daylight time, an Aero Vodochody L-39C airplane, registration N339L, was substantially damaged during an accident near Granite Falls, Minnesota. The flight instructor, seated in the front seat, sustained serious injuries after ejecting from the airplane. The pilot-receiving-instruction, seated in the rear seat, did not eject and was fatally injured when the airplane impacted terrain. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.
Flight Training Background
The flight instructor held an airline transport pilot certificate with multiple type ratings, including the Aero Vodochody L-39, and reported about 50 hours in type. The pilot-receiving-instruction held a private pilot certificate with single-engine land and instrument ratings, plus a Cirrus SF-50 type rating, but had no previous L-39 experience. On July 20 and 21, 2025, the flight instructor provided ground instruction covering aircraft limitations, ejection seat use, flight planning, and other topics. The flight was intended to reposition the airplane from Alpine, Wyoming, to Oshkosh, Wisconsin, for the EAA AirVenture event via three legs. The first two legs were uneventful.
Engine Failure and Descent
During the third leg, while climbing through flight level 200, both occupants smelled an odor from their oxygen masks, followed by cockpit smoke. About 4–5 seconds later, the aircraft shook briefly with a metal-to-metal grinding noise. The flight instructor depressurized the cockpit, resolving the odor and smoke. He decelerated to best glide speed and attempted to restart the engine using the auxiliary power unit (SAFIR air-turbine system) but was unsuccessful. At 1718:05, the airplane began a descent from about 21,800 ft mean sea level. The flight instructor declared an engine failure with air traffic control and was directed toward Granite Falls Municipal Airport (GDB) and nearby airports. The airplane's ground speed decreased significantly, and the flight instructor initially diverted toward Southwest Minnesota Regional Airport (MML) but subsequently resumed heading to GDB.
Ejection and Impact
As the airplane descended through 1,200 ft above ground level over GDB, the flight instructor extended the landing gear during a right descending turn toward runway 15. Determining the airplane would not reach the runway, he told the pilot-receiving-instruction to prepare to eject. After several commands to eject without hearing the rear seat activate, the flight instructor ejected himself as the airplane neared the bottom of the ejection envelope. The front seat ejected, and the flight instructor descended under parachute, sustaining non-life-threatening serious injuries during ejection and landing.
The airplane's upper vertical stabilizer clipped a power line about 821 ft short of the runway overrun. The airplane then impacted a berm adjacent to railroad tracks about 590 ft short of the end-of-pavement and 105 ft right of the extended centerline. The fuselage separated from the wing and came to rest upright about 45 ft past the berm. Fuel was observed leaking from wing tip tanks and fractured fuel lines. The rear canopy was fragmented. The pilot-receiving-instruction was found restrained in the rear ejection seat, which had separated from the airframe during impact. The seat's firing mechanism was unused; bomb squad personnel rendered it safe with a controlled detonation.
Post-accident Examination
The engine bay remained mostly intact. The Ivchenko AI-25TL turbofan engine (serial number 9052524100057) was still mounted. The compressor section had organic debris and a stick wedged between inlet guide vanes and first-stage compressor blades at the 11 o'clock position. The compressor/low-pressure spool was seized and could not be rotated. The low-pressure turbine exhibited thermal damage: first- and second-stage rotor blades and nozzle vanes were partially consumed. Further examinations were pending at a secure location.