What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On 8 April 2025, a Vbat platform was scheduled for a series of flights as part of its operational testing and validation. The incident in question occurred during the platform's third flight of the day. At 1451 hours, the UAV executed a vertical takeoff from the east end of dug "a" taxiway. In its initial climb and transition to horizontal flight. The aircraft ascended to its designated altitude of 1,500 feet AGL, approximately 1 mile northeast of the airfield, without any anomalies.
Two minutes later, after reaching the desired altitude, the flight team observed a critical engine malfunction with engine RPM readings decreasing to zero, indicating a complete engine failure. Despite this, the UAV maintained a stable data link connection throughout the event, with no additional warnings or error messages displayed on the system interface.
In response to the engine failure, the pilot in command (PIC) quickly assessed the situation using the heads-up display, which provided real-time glide ratio metrics. Using this information, the PIC navigated the UAV towards a pre-determined safe landing zone. The UAV executed a controlled descent, making a safe landing approximately 500 feet east of the "a" taxiway. Throughout the descent and landing, the UAV remained in communication with the control team.
Upon securing the aircraft, the ground crew arrived at the landing site to assess the situation. They placed the UAV into safe mode, powering off the system to prevent any further complications. The crew then conducted a thorough visual inspection, documenting the scene with photographs to aid in subsequent analysis. No immediate hazards were detected in the vicinity of the landing site.
A preliminary analysis of the flight data identified the root cause of the engine failure as a malfunction of the ignition servo. This component failure was isolated as the sole issue, with no other irregularities detected in the aircraft's systems during the data review.
As the FAA filed it
ON 8 APRIL 2025, A VBAT PLATFORM WAS SCHEDULED FOR A SERIES OF FLIGHTS AS PART OF ITS OPERATIONAL TESTING AND VALIDATION. THE INCIDENT IN QUESTION OCCURRED DURING THE PLATFORM'S THIRD FLIGHT OF THE DAY. AT 1451 HOURS, THE UAV EXECUTED A VERTICAL TAKEOFF FROM THE EAST END OF DUG "A" TAXIWAY. IN ITS INITIAL CLIMB AND TRANSITION TO HORIZONTAL FLIGHT. THE AIRCRAFT ASCENDED TO ITS DESIGNATED ALTITUDE OF 1,500 FEET AGL, APPROXIMATELY 1 MILE NORTHEAST OF THE AIRFIELD, WITHOUT ANY ANOMALIES.
TWO MINUTES LATER, AFTER REACHING THE DESIRED ALTITUDE, THE FLIGHT TEAM OBSERVED A CRITICAL ENGINE MALFUNCTION WITH ENGINE RPM READINGS DECREASING TO ZERO, INDICATING A COMPLETE ENGINE FAILURE. DESPITE THIS, THE UAV MAINTAINED A STABLE DATA LINK CONNECTION THROUGHOUT THE EVENT, WITH NO ADDITIONAL WARNINGS OR ERROR MESSAGES DISPLAYED ON THE SYSTEM INTERFACE.
IN RESPONSE TO THE ENGINE FAILURE, THE PILOT IN COMMAND (PIC) QUICKLY ASSESSED THE SITUATION USING THE HEADS-UP DISPLAY, WHICH PROVIDED REAL-TIME GLIDE RATIO METRICS. USING THIS INFORMATION, THE PIC NAVIGATED THE UAV TOWARDS A PRE-DETERMINED SAFE LANDING ZONE. THE UAV EXECUTED A CONTROLLED DESCENT, MAKING A SAFE LANDING APPROXIMATELY 500 FEET EAST OF THE "A" TAXIWAY. THROUGHOUT THE DESCENT AND LANDING, THE UAV REMAINED IN COMMUNICATION WITH THE CONTROL TEAM.
UPON SECURING THE AIRCRAFT, THE GROUND CREW ARRIVED AT THE LANDING SITE TO ASSESS THE SITUATION. THEY PLACED THE UAV INTO SAFE MODE, POWERING OFF THE SYSTEM TO PREVENT ANY FURTHER COMPLICATIONS. THE CREW THEN CONDUCTED A THOROUGH VISUAL INSPECTION, DOCUMENTING THE SCENE WITH PHOTOGRAPHS TO AID IN SUBSEQUENT ANALYSIS. NO IMMEDIATE HAZARDS WERE DETECTED IN THE VICINITY OF THE LANDING SITE.
A PRELIMINARY ANALYSIS OF THE FLIGHT DATA IDENTIFIED THE ROOT CAUSE OF THE ENGINE FAILURE AS A MALFUNCTION OF THE IGNITION SERVO. THIS COMPONENT FAILURE WAS ISOLATED AS THE SOLE ISSUE, WITH NO OTHER IRREGULARITIES DETECTED IN THE AIRCRAFT'S SYSTEMS DURING THE DATA REVIEW.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.