BAE Systems has announced that its Persistent High-Altitude Solar Aircraft (PHASA-35) completed critical endurance trials.

The PHASA-35 is a solar-electric aircraft with a wingspan of 35m.

It follows the maiden flight of PHASA-35 in February that paved the way for future persistent surveillance technology.

During the critical endurance trials, the aircraft was operated in difficult stratospheric conditions in a simulated environment for 72 hours.

The aircraft trials were carried out along with BAE Systems, Prismatic and the UK’s Defence Science and Technology Laboratory (Dstl).

The critical ‘soak’ tests showcased that the aircraft worked effectively as a fully integrated system with the communications sensor payload by Dstl.

Further, testing was carried out using a series of ground-based tests, which drove pace and reduced the developmental phase costs.

They were carried out in a 40m hangar at Prismatic’s facility near Farnborough, UK.

Additionally, the tests allowed the team to practice different operations required in-flight such as the transition from daytime to night-time.

BAE Systems Air chief operating officer Ian Muldowney said: “PHASA-35 is a great example of how we’ve brought together the best in British expertise and partnered to drive technological innovation and deliver critical capability.

“This latest success, only eight months after PHASA-35’s maiden flight, further demonstrates how UK industry and our partners are accelerating pace to deliver the UK’s vision for innovation, a Future Combat Air System and information advantage.”

In the next few months, BAE Systems plans to carry out further flight trials.

After the conclusion of the flight trials programme, the aircraft is expected to commence initial operations within 12 months.