A massive modernization push is imminent for Russian aerospace defense: The air force alone could receive 4.5 trillion rubles ($136 billion) over 10 years, about one-quarter of the overall drive to upgrade Russia's Soviet-era weaponry.

The money will help replace about 70% of the air force fleet by 2020 and position it to acquire the Sukhoi T-50—a fighter advanced enough to rival the F-35 Joint Strike Fighter—as well as a stealthy, long-range bomber, and to overhaul its surface-to-air missile stockpile. However, analysts caution that the plan's financial scope may be unrealistic.

For now, the investments are on track. During a series of briefings by military officials and defense manufacturers in late November, Russian President Vladimir Putin approved the procurement program adopted in 2010. The meetings amounted to the first public audit of the program to ensure that the investments are on track—a domestic show of support for the Russian defense industry, despite the country's economic stagnation.

The list includes accelerating replacement of old aircraft in the air force fleet. Putin has announced that the military will have received 86 new and, modernized fixed-wing aircraft and more than 100 new helicopters this year, and will take delivery of up to 120 fixed-wing aircraft and 90 helicopters in 2014. In 2011 and 2012, just 263 new aircraft were delivered to the military units.

By 2020, the air force aims to have a total of 1,600 new aircraft, renewing about 70% of its fleet.

So far, the air force's orderbook consists of Sukhoi Su-34 fighter-bombers and Su-30M2/SM and Su-35 multirole fighters. In 2014, the air force plans to rearm one air regiment with the Su-34s, according to Defense Minister Sergey Shoigu. A training air base in Borisoglebsk is to be reequipped with Yakovlev Yak-130 jet trainers; 18 of the type were delivered in 2013, out of 55 ordered.

According to the head of the United Aircraft Corp. (UAC), Mikhail Pogosyan, the Sukhoi T-50 will start official evaluation tests with the air force in 2014. The first phase of these trials is expected to be completed in 2015, he says. The five prototypes involved in the preliminary test program have logged more than 450 flights. The Russian defense ministry issued technical requirements for the future long-range bomber to the corporation in September. “We are now at the stage of drawing up the contracts to start the full-scale development of this aircraft beginning next year,” Pogosyan says.

The air force expects the stealthy bomber aircraft, to be developed under the PAK DA program, to replace its current strategic bomber fleet of Tupolev Tu-160 Blackjacks, Tu-95 Bears and Tu-22M3 Backfires by 2025-30. Meanwhile, the veteran bombers are being upgraded with new avionics and airborne weapons. UAC completed factory testing of the upgraded versions of the Tu-160 and Tu-95 and is handing them over for the official trials.

The procurement program also calls for enhanced air transport capabilities for the air force. In November, UAC completed the first phase of official tests of the Il-76MD-90A, a much modernized Ilyushin Il-76 heavy transport aircraft. During this phase, the aircraft completed 38 flights, including tests at the maximum takeoff and landing weights (210 tons and 170 tons, respectively). The air force has 39 transports on order; the modifications will be done in Russia, although the older variants were manufactured in Uzbekistan. Pogosyan has promised that deliveries will start next year. The UAC has begun development of medium transport aircraft as a joint program with India and completed the detailed design of a new light transport, Pogosyan says.

Meanwhile, the aerospace defense troops are being reequipped with the S-400 (SA-21 Growler) long-range air defense and anti-ballistic missile systems. Two units of these surface-to-air missiles (SAM) were delivered this year and three more are to be deployed in 2014, Putin says.

S-400 manufacturer Almaz-Antey is working on a next-generation system, the S-500, that will undergo intensive trials in 2014-15, says the company's chief designer, Pavel Sozinov.

The aging S-300PT and PS (SA-10 Grumble), the most common air defense missiles in the force, will be replaced by new S-350 Vityaz medium-range mobile SAMs unveiled this summer. Sozinov says official trials will be conducted during 2014 and deliveries could start in 2015-16.

The aerospace defense troops' missile capabilities will be supported by expansion of the early-warning radar network. The service operates three Voronezh modular radar stations and plans to deploy seven more in the next five years.

Defense experts are quite skeptical of the rearmament program's feasibility, however. “Even if the program is properly financed, it is unlikely to be fully implemented, as the required modernization of defense industry facilities and the respective regulatory environment lag behind,” says Konstantin Makienko, deputy director of the Center for Analysis of Strategies and Technologies, a Moscow-based defense think tank.