London ? An ultra-lightweight plane built from carbon fiber and powered using paper-thin solar panels has broken the world record for longest-lasting unmanned flight, its manufacturer claimed Sunday.

QinetiQ Group PLC said its propeller-driven “Zephyr” aircraft flew for 83 hours and 37 minutes, more than doubling the official world record set by Northrop Grumman’s “Global Hawk” in 2001.

The flight also went longer than a previous excursion by the Zephyr, which QinetiQ claims clocked 54 hours of continuous flight last year.

However, both the Zephyr’s reported flight times are likely to remain unofficial because they did not meet criteria laid down by the world’s air sports federation, the body responsible for measuring and verifying air and space records.