Northrop Grumman's high-altitude long-endurance (HALE) RQ-4 Global Hawk set an endurance record on Saturday 22 March when it completed a flight of just over 33h at altitudes up to 60,000ft (20,000m) over Edwards Air Force Base in California.

The aircraft, designated AF-8, is the first Global Hawk Block 20, tail number 04-2015. It landed with 2h worth of fuel left after surpassing endurance records held by its Block 10 variant. The unmanned air vehicle is designed to fly up to 65,000ft for more than 35h and endure any inclement weather.

Global Hawk chief engineer Bryan Lima says: "This was the longest mission ever flown by a HALE or medium-altitude long-endurance aircraft."

According to Northrop, three Global Hawks are currently deployed in the US government's "war on terror" and between them have amassed over 15,700 combat hours, more than 21,000 total programme flight hours and have a 95% mission effectiveness.

Global Hawks cost about $28 million each, averaged across the entire USAF fleet of 54 aircraft. They are flown from USAF bases Beale and Edwards in California, and Patuxent River Naval Air Station in Maryland.