Fighters and missiles combine to counter stealth technology
Russia's technological strategy for post-2010 airpower, mapped out in considerable detail during the late 1990s, is reflected in emerging prototype and early production systems for both aircraft and air-defense weapons.
Unlike many nations that have followed ad hoc strategies for defining future weapon systems—often influenced by industrial base and existing force structure concerns—Russian defense planning has been systematic and disciplined in its approach, intended to symmetrically challenge U.S. strengths and asymmetrically challenge U.S. weaknesses. The strategic intent is to enhance Russia's political freedom of action in a U.S.-dominated post-Cold War world, while using arms export revenues to relieve the pressure on limited defense resources.
Russian choices have been guided by a consistent Western tactical air defense plan that has been centered on theJoint Strike Fighter. Delays in the JSF program have now given Russia more than 20 years to prepare for its initial operational capability date.
For aircraft, Russian defense planners have chosen quality over numbers, with the future force being based on three 30-ton-plus fighter-strike aircraft from Sukhoi, two of them direct developments of the Su-27 “Flanker” family. The smaller MiG-29/35 has been developed and offered for export only.
The most mature of the three is the Su-34 strike fighter/medium bomber. The first batch of six production-standard Su-34s, out of an initial order of 32 aircraft, has been delivered to a tactics development unit at Lipetsk, and 10 more are due to arrive this year; an order for another 92 aircraft was announced on March 1, to be delivered by 2020. Under development since the late 1980s, the Su-34 replaces the Su-24 “Fencer” in land and maritime strike, suppression/destruction of enemy air defenses and other missions, while having the speed and agility to defend itself.
The third production-standard example of the Su-35S air superiority fighter started its flight tests on Jan. 17. At that point, according to Sukhoi, two Su-35 prototypes (one was lost in a runway overrun early on) had performed 400 flight tests, and formal state acceptance trials started in August 2011, along with the first production aircraft.
The Su-35S is a substantially refined development of the original “Flanker.” Thrust vectoring is effective in yaw, pitch and roll, and fully integrated with the aerodynamic flight controls. This has permitted the elimination of the canard surfaces on the Su-30MKI and similar versions, which restricted maximum Mach to 1.8, along with a separate airbrake, saving weight and adding fuel capacity. As well as providing the fighter with exceptional maneuverability, the integrated flight and propulsion control is considered a safety benefit, making the fighter departure-resistant even in asymmetrical conditions.
The 117S engines increase available thrust by up to 16%, but new materials and refined structure keep weight close to that of the original aircraft. Radar cross-section (RCS) has been reduced, using 1990s technology developed by ITAE, and the new avionics suite includes a wide-field-of-regard radar, which combines a passive, electronically scanned array with a mechanical gimbal.
Taken together, the new features of the Su-35S point to an effort to reduce the effective range of any hostile anti-aircraft missile: lower RCS and better jamming to complicate tracking, better agility to stress the missile's kinematic performance, combined with a radar that can maintain situational awareness or guide a counter-attack through an evasive maneuver. It was the vulnerability of the U.S. Air Force's Advanced Medium-Range Air-to-Air Missile to such countermeasures that originally inspired development of the MBDA Meteor.
Photos and videos of flight testing have underlined the radical nature of the third Sukhoi type, the T-50, the third prototype of which—with provision for radar and other sensors—flew in late November, just after the program notched its 100th test flight. Building on the foundation of the earlier designs, with the broad inner “centroplane,” vectored thrust and widely separated engines, the T-50 adds new control surfaces on the leading edge of the centroplane. These surfaces can operate differentially over a wide range of motion. The widely separated nozzles have their vectoring axis aimed outward and upward, about 30 deg. from the vertical, so that they can produce pitch, roll and yaw moments. The small vertical stabilizers are all-moving.
One question that has no official answer is whether the current T-50 represents the definitive configuration. Today's round nozzles and the curvature of the aft nacelles are not at first glance stealth-optimized, and the engine is not fully masked head-on by the inlet duct.
The Su-35S and T-50 programs are related insofar as some Su-35S features, such as the big-screen cockpit displays and integrated flight/propulsion control, will provide experience for the T-50 developers. The Saturn 117S engine used on the Su-35S is a precursor to the 117 used on the T-50.
The asymmetric dimension to future Russian air warfare programs entails the development of counter very-low-observable (CVLO) radar technologies and long-range, high-speed surface-to-air missile (SAM) designs, complemented by a new generation of short-range point defense weapons intended to destroy incoming guided weapons, especially anti-radiation missiles, cruise missiles and guided bombs. All systems are built for high mobility, typically with 5-min. “shoot and scoot” times to permit “scooting” inside of the targeting and engagement cycles of most guided munitions.
The focus in Russian CVLO radar has been in the 1-meter VHF band. Stealth shaping in fighters is largely ineffective in VHF because components such as stabilizers and wingtips have dimensions close to the radar wavelength. Radar-absorbent treatments developed for S-band and above are ineffective in VHF due to both electrical behavior and thickness.
The flagship product is the NNIIRT/Almaz-Antey 55Zh6M Nebo M 3-D radar system, of which 100 were recently ordered to re-equip Russian air defense forces. The Nebo M is uniquely a “multi-band” design, comprising three radars and a central data fusion and command post module, all carried on separate high-mobility 8 x 8 24-ton vehicles.
The RLM-M VHF-band, RLM-D L-band and RLM-S C/X-band radars all feed tracking data to the command van's data fusion system—which resembles the U.S. Navy's Cooperative Engagement Capability system—using high-speed narrow-beam digital data links in the microwave band. All radars appear to be solid-state active, electronically scanned array (AESA) designs. The intent of the Nebo M design is for the RLM-M to detect stealth targets, and cue the RLM-D and -S components to produce exact tracking data, bypassing the initial acquisition problems otherwise seen in mid/upper-band radars with VLO targets. Range performance has not been disclosed but the RLM-M is expected to better the earlier Nebo- SVU by at least 40%.
The earlier NNIIRT 1L119E Nebo-SVU VHF AESA does not appear to have been built in large numbers, and used a less mobile semi-trailer configuration. The Nebo-SVU was credited with space-time adaptive processing technology similar to that or theE-2D Hawkeye, and in 2002 NNIIRT's Igor Krylov said “We can see the stealth [F-117A] as clearly as any other plane”.
The push into CVLO radar is paralleled by investment in highly mobile long-range SAM designs with high speed and short flight times. The intent is twofold—to deny airspace to standoff and penetrating intelligence, surveillance and reconnaissance and electronic attack platforms, while permitting SAMs to close with stealth targets before they can retreat from tracking range.
Russia's future integrated air defense system will be constructed around the S-400 Triumf (SA-21 “Growler”) strategic SAM, and the S-500 Triumfator M or SA-X-NN SAM and missile defense system. The S-400 is now deployed with air defense regiments at Dubrovka, Elektrostal and Vladivostok.
The S-400 is a direct evolution of the S-300PMU2 (SA-20B “Gargoyle”), retaining the space feed X-band engagement radar, tubular launch containers and basic missile airframe. The digital multimode 92N6E Grave Stone uses Sparc digital processing, and directional microwave data links to missile transporter erector launchers (TELs) and acquisition radars, such as the heavily revised 91N6E battle management radar that is based on the 5N64/64N6E/E2 Big Bird series. New semi-trailer 5P85TE2 and 8 X 8 self-propelled 5P90S/SE TELs), based on the BAZ-6909, replace earlier designs.
The baseline 48N6E3/DM missile is an enhanced “Gargoyle” with a cited range of 250 km (155 mi.). It is soon to be supplemented by the yet-to-be-seen new 40N6 missile credited with a range of 400 km. Belarus will be the first export client.
In a parallel development, army air defense units are receiving the S-300V4 upgrade to the legacy “Sprint-like” S-300V (SA-12 “Giant”/”Gladiator”) SAM/ABM, involving tracked TEL upgrades and the new 9M82M and 9M83M missiles developed for the Antey-2500 or SA-X-23, credited with 200-250 km and 120-130 km ranges, respectively. Russia has yet to disclose whether the 9S32 Grill Pan radars are to be replaced by the larger 9S32M Grill Screen in the S-300V4 program.
The upper tier of the future Russian SAM network is the S-500, currently in advanced development. Disclosures have been limited, but material released in mid-2010 suggests a missile derived from the 9M82M is likely, with a range of 500-600 km and ABM capability. The radar suite is to comprise the Big Bird-derived 91N6A(M) acquisition and battle management radar, the revised 96L6-TsP acquisition radar, and the new 76T6 multimode engagement and 77T6 ABM engagement radars.