Sukhoi has conducted the first flight of its prototype PAK FA fifth-generation fighter, with the aircraft having conducted a 47min sortie this morning.

Flown from KnAAPO’s Komsomolsk-on-Amur site, the PAK FA was piloted by Sergei Bogdan, and “performed excellently”, says Sukhoi.

“In the course of the flight we conducted initial evaluation of the aircraft controllability, engine performance and primary systems operation,” says Bogdan. The aircraft’s landing gear was also retracted and lowered during the first flight.

 PAK FA 2 - Sukhoi

PAK FA take off - Sukhoi

Both images © Sukhoi

The PAK FA is powered by two NPO Saturn "Item 117" engines, developed from the Item 117S design already flown on Sukhoi’s Su-35 and a Su-27M testbed. The experimental aircraft’s integrated flight control system controls the engines, along with all other major systems.

Sukhoi says other key design elements include the use of composite materials, advanced aerodynamic techniques and measures to reduce the aircraft’s engine signature, which it claims results in an “unprecedented small radar cross section in radar, optical and infrared range”. The PAK FA is also equipped with an advanced phased-array antenna radar, it adds. Russia's Tikhomirov NIIP displayed an active electronically scanned array design for the fighter at last year's Moscow MAKS air show.

 PAK FA aloft - Sukhoi
© Sukhoi

Some observers have drawn similarities between the Russian design and the Northrop/McDonnell Douglas YF-23, which lost the US Air Force’s advanced tactical fighter contest to the Lockheed Martin F-22 Raptor. The PAK FA also has some characteristics in common with both US designs, such as supercruise performance and internal weapons bays.

Featuring large and deeply set intakes that are likely to shroud the engines from head-on view, and also from radar signals from above, the PAK FA also uses comparatively small and canted horizontal and vertical tail surfaces to boost its stealthy characteristics.

“The massive delta wing, allied with its powerful engines, should make it a potent turning machine at high level,” says Flight International test pilot Peter Collins. “But the exposed exhaust nozzles suggest that they don’t consider IR stealth to be that important.”

The aircraft also has a strong resemblance to an image posted on NPO Saturn's website in 2007 (below) and reported on at the time by Flight International.

 F-22A Raptor
© NPO Saturn

“This is a great success of both Russian science and design school,” says Sukhoi director general Mikhail Pogosyan. “The PAK FA programme advances Russian aeronautics, together with allied industries, to an entirely new technological level.

“These [PAK FA] aircraft, together with upgraded fourth-generation fighters, will define Russian air force potential for the next decades,” he adds.

The first stage of flight trials involving the PAK FA prototype will last until 2012, when the Russian defence ministry and air force are expected to decide on the future of the project. A production version is expected to be designated the T-50.

 PAK FA taxi - Sukhoi
© Sukhoi

The new design could also form the basis of a proposed fifth-generation fighter to be produced in collaboration between Russian and Indian companies.

“I am strongly convinced that our joint project will excel its Western rivals in cost-effectiveness and will not only allow strengthening the defence power of Russian and Indian air forces, but also gain a significant share of the world market,” says Pogosyan.

Additional reporting by Craig Hoyle in London