R-27 (AA-10) Medium-Range Air-to-Air Missile

The PLAAF received the R-27 (AA-10 Alamo) semi-active radar-homing medium-range air-to-air missile (MRAAM) in the early 1990s as part of the weapon package for its Su-27 fighters acquired from Russia. R-27 missiles in service with the PLAAF may include three models: the semi-active radar-homing variant R-27R (AA-10A Alamo-A), the IR-homing variant R-27T (AA-10B Alamo-B), and the active radar-homing variant R-27AE (AA-10 Alamo-E).

It is not clear whether the missiles received by the PLAAF are standard R-27R and T models, or their downgraded export variants are known as R-27R1 and R-27T1. Vympel Design Bureau also developed the extended-range (120~130km) variants of the two missile known as R-27RE and R-27TE. The R-27TE later became the base of the more capable R-27AE (AA-10E Alamo-E) variant featuring an active radar-homing seeker. Public photos of the Chinese Su-27 showed that the PLAAF was equipped with the R-27AE.

Intended as a counter to the U.S. AIM-7F Sparrow, the R-27 family of MRAAM was introduced in the 1980s for the Soviet Union’s fourth-generation fighters such as the Su-27 and Mig-29, with a total of six variants developed with different seekers and engines. The missiles was designed to intercept and defeat fixed-wing aircraft, helicopters, unmanned aerial vehicles, and cruise missiles in long-range and close manoeuvrable air-to-air combat, under heavy enemy jamming and countermeasures conditions. Like many Soviet air-to-air missiles, the R-27 came in two variants: R-27R (AA-10A Alamo-A)  with a semi-active radar-homing seeker and R-27T (AA-10B Alamo-B) with an infrared seeker. The standard Soviet tactic for interceptions is based on firing two missiles with different seeker types at the same target to maximize kill probability.

The R-27 is generally based on the 1970s/80s Soviet technology and does not possess the real “fire-and-forget” capability. Only a limited number of the missile has been acquired by the PLAAF for its Russian-built Su-27 fighters. The Chinese license-built version of the Su-27, designated J-11, may be equipped with an indigenous MRAAM. The newer Su-30MKK is equipped with the more advanced R-77 (AA-12 Adder) active radar-homing MRAAM.

Design

The R-27 features a long, slim missile body and canard aerodynamic configuration with an axially symmetric cruciform arrangement of aerodynamic surfaces. Each of the four unique “butterfly”-shape large control surfaces has an independent hydraulic drive with a pump-accumulator system for supplying pressure fluid, allowing using the same surfaces both for missile yaw and pitch control as well as for its roll stabilization. Each of the four control surfaces. The missile adopts a modular design, allowing easy conversion between two guidance types by simply replacing the missile seeker module.

The missile is guided to the target by a combination of different methods to provide reliable target lock-on at long ranges from the carrier aircraft. Initially the missile is guided by inertial guidance, with radio midcourse correction command. In its final stage of flight, the missile switches to semi-active radar-homing mode, or active infrared-homing mode depending on the type of the seeker. The missile can be guided along special trajectories to create favourable conditions for homing head and proximity fuse operation. It is also capable of going around a plume of passive jamming, of being moved out of the main lobe of the platform's radar, and approaching a low-flying target from above at a given angle.

Specifications

Last update: 20 October 2008