MOSCOW, May 18. /TASS/. The prototype of the large-wingspan Skydweller unmanned aerial vehicle (UAV) has completed a record-breaking eight-day flight (more than 192 hours), before coming down over the Gulf of Mexico due to poor weather conditions, the drone manufacturer Skydweller Aero reported on May 12.

The aircraft, tail number N247PF, took off on April 26 from Stennis International Airport in Mississippi. Then, for over four days, until April 30, the solar-powered UAV continuously performed reconnaissance and surveillance missions as part of the US Navy’s annual Fleet Experimentation (FLEX) 2026 exercise.

After the exercise concluded, a cold front over the Gulf of Mexico forced the Skydweller to remain airborne for over three more days. It wasn't until May 3 that the drone began its return to its base in Stennis. However, during the return transit, the aircraft encountered more severe weather than forecast, including heavy turbulence and vertical drafts, causing climb and descent rates in excess of ten times typical rates.

The company emphasized that although the airframe and autonomous control systems were functioning normally, the load on the drone's batteries proved too great to keep it airborne. On the morning of May 4, the Skydweller was forced to go down in the water, where it subsequently sank. "The aircraft completed a historic multi-day autonomous mission and supported Navy exercise objectives, executing a controlled ditching only after its energy reserves were depleted by sustained, extreme weather conditions. All aircraft structures, systems, and redundancies were nominal except battery energy levels," the company said in a statement.

The aircraft was developed by Skydweller Aero based on the Solar Impulse 2 manned aircraft. The drone is classified as a Medium-Altitude Pseudo-Satellite (MAPS) and is designed to perform long, nonstop flights lasting from several weeks to several months by constantly recharging its batteries from solar panels.

The Skydweller has a very large composite wing, 72 meters long, similar to a Boeing 747, which houses 17,000 solar panels. It can carry a payload of up to 400 kg.

To perform maritime patrol missions within the FLEX 2026 framework, the UAV was equipped with an AN/ZPY-8 SAR track generation for target tracking and a FLIR 380X HDc electro-optical/infrared imaging for target observation, along with other unspecified equipment.