R-112 Credit - © Mark Wade

Soviet surface-to-air missile design of 1948-1951. Propulsion and guidance based on that of the R-102 (copy of German Schmetterling) but with new aerodynamics. Cancelled without ever flying in 1951 when decision was made to proceed with a new generation of SAM designs.

The R-112 was an advanced medium surface-to-air missile derived from the R-102 (Schmetterling). SKB-5 of NII-88 under Chief Designer Semyon Yevelyevich Rashkov was authorised to begin work on the design in a decree of 14 April 1948. The missile was to be produced in three variants: R-112A, with a self-homing guidance system and a 160 kg warhead; the R-112B, unguided but with a 270 kg warhead; and the R-112S - unguided but powered by a ramjet engine. Subcontrctors included: NII-504 MSKhM - target-ranging system; NII-885 MPSS - telemetry and control systems; NII-6 MSKhM - solid propellant booster motors; NII-6 MSKhM - warhead; MV - self-destruct system; and TsAGI MAP - aerodynamic layout.

The draft project for the R-112 was defended before a plenary session of NTS NII-88 on 4 August 1949. The rocket as designed would used two solid propellant boosters. These would burn out 2 to 3 seconds from launch, after which the missile would cruise to the target under the power of a liquid propellant engine. The missile had a total mass of 1500 kg, would reach a speed of 700 m/s, an altitude of 15 km, and a range of 20 km. Accuracy was 25 m at 20 km range. Maximum target speed was 300 m/s.

Aerodynamically the missile was equipped with two fixed wings and two rudders in-line. A launch battery would consist of six trailer-launchers, with one missile per launcher. All six could be fired within 13 seconds. No external guidance was to be provided to the missiles. The draft project consisted of 12 volumes; volume 11 dealt with the R-112S ramjet version. Rashkov was still the overall designer for this variant, but Mikhail Makarovich Bondaryuk of OKB-3 NII-1 TsIAMI was responsible for the integral ramjet and associated aerodynamics. Within NII-88 a half-scale flying prototype of the R-112S had been built. By May 1949 the following models had been delivered for test in the wind tunnels of NII-88 Section 11:

• Model 1, with a diameter of 75 mm, for analysis of the internal ramjet diffuser channel performance.
• Model 2, with a 120 mm in diameter, to study external aerodynamics in a closed wind tunnel.
• Model 3, also 120 mm in diameter, used to verify full-scale aerodynamic effects in an open wind tunnel, as a basis for comparison with model 2.

During boost, the elevons were locked at a 45 degree angle. After burnout and separation of the solids, a 2 tonne thrust liquid propellant engine by Isayev took over. This burned a mixed synthetic oxidiser and kerosene propellants, a combination that had been recommended for manoeuvring rockets.

Section 5, after the cancellation of the R-102, still continued work on the R-112. Furthermore the missile's future seemed assured when the R-112 was chosen over the R-117 in June 1950. Ironically, further work on the R-112 was in turn cancelled on 17 August 1951, when the decision was made to cancel all German-derived surface-to-air missiles in favour of new approaches.

Manufacturer: Rashkov. Total Mass: 1,500 kg (3,300 lb). Maximum range: 20 km (12 mi). Boost Propulsion: Solid rocket, 2 x boosters. Cruise Propulsion: Storable liquid rocket. Ceiling: 15,000 m (49,000 ft).

• Yeftifyev, M D, Iz istorii sozdaniya zenito-raketnovo shchita rossii, Vuzovskaya kniga, Moscow, 2000. Comprehensive history of development of the development of surface-to-air and anti-ballistic missiles in the Soviet Union, with summaries of work in other countries as well. Accessed at: http://www.eastview.com/xq/ASP/sku=A2010232/f_locale=/Evtif'ev/MD/Moskva/Russia/Russian/qx/russian/books/product.asp.