The System 49 design had the same arrangement as Spiral. The rocket stages and the Spiral orbiter were mounted on the back of an An-124 subsonic transport. By the time of the design, the Spiral configuration had been proven in the MiG-105-11 and BOR-4. The combined orbiter and rocket stages, weight 200 tonnes, would be launched at an altitude of 10 km and a speed of Mach 0.7. Effective velocity gain compared to a vertical launch from the ground was 270 m/s.

The first stage would use Lox/Kerosene propellants and 2 NK-43 / 11D112 engines. The second stage was equipped with a single RD-57M / 11D57M engine burning Lox/LH2 propellants. Two rocket stage layouts were studied: a traditional tandem scheme, and a 'piston' / 'wrap around' concept, where the toroidal propellant tanks of the first stage surrounded the second stage.

The orbiter would have a mass of 13 tonnes, and could deliver a payload of 4 tonnes to orbit in a 27 cubic metre payload compartment (dimensions 6.0 m long x 2.8 m x 1.6 m). Orbits from 120 to 1000 km altitude, and 45 to 94 degrees inclination could be achieved thanks to the flexibility of airborne launch. The orbiter was flown by a single pilot, had sufficient consumables for 5 to 12 hours of on-orbit operations, and was designed for 100 reuses. It could achieve up to 1000 km cross-range during re-entry and landed at a speed of 300 to 310 km/hr.

The design was found to be feasible but to have little growth potential. Greater payload could only be achieved by the completely different 49M using a new super-heavy carrier aircraft and orbiter. Therefore it was succeeded in the design studies by the 'Bizan' concept.