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

The R-27 (NATO codename: AA-10 Alamo) is the medium-range air-to-air missile (MRAAM) developed by the Soviet Union/Russian Vympel Design Bureau in the early 1980s. The PLAAF received the missile as a part of the weapon package for the Su-27 fighters it purchased in the early 1990s. Currently the PLAAF is equipped with at least 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).

The R-27 (AA-10) MRAAM family 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 missile is also carried by improved versions of the MiG-21, MiG-23 and MiG-25. The missile was developed as a counter to the U.S. AIM-7F Sparrow MRAAM. China purchased unknown numbers of the R-27 missiles in several batches during the 1990s to arm its Su-27 fleet.

The R-27 missiles was designed to intercept and defeat fixed-wing aircraft, helicopters, unmanned aerial vehicles, and cruise missiles in long-range and close maneuverable 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 with semi-active radar-homing or 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 semi-active radar-homing variant is designated R-27R (AA-10A Alamo-A), and the infrared homing variant is designated R-27T (AA-10B Alamo-B).

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 show that the PLAAF is also equipped with the R-27AE.

Due to the serious delay in China’s own indigenous MRAAM programme, the R-27 missiles served as a stopgap to fulfil the PLAAF’s urgent requirement for “beyond-visual-range” (BVR) combat capability. The R-27 is generally based on the 1970s/80s Soviet technology and does not possess the real “fire-and-forget” capability like the R-77 (AA-12 Adder) and AIM-120 (AMRAAM). The PLAAF is planning to replace the missile with the more capable Russian model such as R-77 or an indigenous design such as PL-12, both of which feature the active radar-homing seeker.

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.