The Buzz

Russia's PAK-FA Stealth Fighter Takes Another Step Forward

Russia has started flight-testing a new next-generation integrated avionics suite onboard its Sukhoi T-50 PAK-FA fifth-generation stealth fighter. The new avionics package is similar in concept to how American fifth-generation fighters such as the Lockheed Martin F-22 Raptor and F-35 Joint Strike Fighter fuse data from various sensors and allows the pilot to see the information in a single coherent and easy to read display.

According to a United Aircraft Corporation—Sukhoi’s parent company—blog post, the new IMA BK integrated avionics suite automatically detects, identifies and tracks the most dangerous targets and offers the pilot the best solution to engage an enemy. “The new system takes control of almost all of the key sensors of the aircraft—radar, navigation and communication that in previous aircraft were controlled by separate computers,” the company says.

The new avionics suite—called the IMA BK, the Russian acronym for integrated modular avionics combat systems—replaces a system designed in 2004 called Baguette. The new system has a software load that already exceeds 4 million lines of code, according to UAC. But the system is still a work in progress. The company still has to add more code to fully implement the functionality of all of the PAK-FA’s combat avionics.

The IMA BK makes use of indigenous Russian multi-core microprocessors and a new indigenous real-time operating system. The new avionic suite also makes use of fiber-optic channels with a throughput of the more 8 Gb/sec, which is up from 100 Mbit/sec for traditional copper wires, according to UAC. The system is designed to be completely modular and easily upgradable. “Multi-core gives us almost unlimited possibilities for the design of fault-tolerant configurations, while saving on weight, power consumption and cost of the equipment,” Dmitry Gribov, chief designer at Sukhoi, said.

The system is similar in concept to the integrated avionics suite found onboard U.S. fifth-generation fighters in many respects. “Probably, it is just something like that. Something you would expect from the fifth-gen,” Vasily Kashin, a senior fellow at the Center for Comprehensive European and International Studies at Moscow’s Higher School of Economics told The National Interest. “I think it is natural that Russian developers tried to follow the same trend.”

The Russians might eventually retrofit the new avionics core into their older fighters such as the Su-30SM and Su-35. Unlike U.S. defense contractors, Russian designers often port avionics to different airframe designs rather than reinvent the wheel each time. Indeed, many of the avionics from the Su-35 were used in original Baguette package onboard the PAK-FA prototypes. “It is for fifth-gen—to be installed on the T-50,” Kashin said. “Maybe they will later use it to upgrade fourth-gen fighters, but basically, it is for the 5th gen.”

The Russian will almost certainly build the PAK-FA in numbers once development and testing is complete. However, the initial batches will be relatively small. “It’s sure to happen for two reasons: Both the U.S. and China have fifth gen and we have a big cooperation project with India, and without it, we will lose the market,” Kashin said. “As I understand, they will first produce 12 planes, then extensively test those aircraft and then order additional examples. For fifth-gen, achieving IOC [initial operational capability] is a very long story.”

Moscow is likely to maintain a mixed fleet of fourth and fifth-generation fighters for the foreseeable future. One of the reasons is cost—fifth-generation aircraft are expensive. “I think there will be a mix even in U.S. since the USAF intends to keep F-16s flying until 2040s, as I understood and definitely there will be a mix in China,” Kashin said. “It seems no one can afford to maintain an air force consisting of only fifth-gen fighters. Too costly and redundant for most missions.”

Indeed, Kashin foresees the future Russian Air Force having three tiers to deal with different types of threats. “On the bottom, Su-25 upgrades and the MiG-35. In the middle, the Su-30 and 35. And some T-50s on top,” Kashin said.

Dave Majumdar is the defense editor for The National Interest. You can follow him on Twitter: @davemajumdar.

Image Credit: Creative Commons.