The "Jet Belt" used a small turbofan engine which was mounted vertically, with its air intake downward. Intake air was divided into two flows. One flow went into the combustion chamber, the other flow bypassed the engine, then mixed with the hot turbine gases, cooling them and protecting the pilot from the high temperatures generated. In the upper part of the engine the exhaust was divided and entered two pipes which led to jet nozzles. The construction of the nozzles made it possible to move the jet to any side. Kerosene fuel was stored in tanks beside the engine. Control of the turbojet pack was similar to the rocket pack, but the pilot could not tilt the entire engine. Maneuvering was by deflecting the nozzles. By inclining levers, the pilot could move the jets of both nozzles forward, back, or sideways. The pilot rotated left/right by turning the left handle. The right handle governed the engine thrust. The jet engine was started with the aid of a powder cartridge. While testing this starter, a mobile starter on a special cart was used. There were instruments to control the power of the engine, and a portable radio to connect and transmit telemetry data to ground-based engineers. On top of the pack was a standard auxiliary landing parachute; it was effective only when opened at altitudes above . This engine was later the basis for the propulsion units of Tomahawk and other cruise missiles.