The PBS TJ100 jet engine is the most successful product in the PBS Velká Bíteš engine portfolio. The jubilee thousandth engine was dispatched to the Asian market.
The engine broke also into the demanding North American market where it represents a driving unit for a small SubSonex jet plane supplied by Sonex Aircraft. The market of flying target drones represents the primary field of commercial applications.

Beginning of development

The beginnings of the development of PBS jet engines date back to 2001, when it was necessary to provide a new production programme to replace the terminated production of devices for the project of the L-159 plane from Aero Vodochody.
The engine excels in its compactness, low weight, reliability and low fuel and oil consumption. All engine systems except for ignition are integrated in the engine. Testing of the first functional sample commenced in 2002.
The following year, we managed to conclude the first contract and, from 2004, start serial deliveries to the Spanish company INTA,  which incorporated the engine into a flying target. A number of variations of the engine which were customized to specific customer projects have been created during progressive development. Among others, the company managed to extend the service life from 50 h to 300 h and to enlarge a flight envelope to 10 km thanks to engine development. Other engine versions such as the one without an independent oil system or the version for repeated landing in salt sea water have been progressively developed.

Engine installation

The PBS TJ100 is a single-shaft jet engine with one-stage radial compressor, ring combustion chamber, one-stage axial turbine and outlet nozzle. Oil system, fuel system and electric system devices are also included in its basic configuration. The oil system ensures bearing lubrication of the main rotor bearings. The fuel system ensures the supply of fuel in the combustion chamber. The main system of the electric installation includes also the engine control unit (FADEC). This unit controls and monitors the safe operation of the engine including its starting, maintaining the required speed and correcting the maximum shaft speed according to the intake temperatures flue exhaust gas fumes. The engine consists of a starter generator, an ignition exciter system and a power supply unit with DC-DC converter for the needs of power supply in the board network of up to 750 W.
Castings of turbine impellers and guide wheels belong to the most sophisticated components supplied by the precision casting division. They are technically very challenging castings operating at temperatures of up to 880 °C. These components are cast from special nickel IN 713LC alloy.

Engine testing

Each newly produced engine must undergo a basic production test during which engine running-in is carried out. The aim of this test is to verify whether the engine complies with the basic technical requirements and reveal potential imperfections remaining after the production and assembly process. If the engine complies with these requirements, an acceptance inspection follows. The purpose of this test is to ascertain whether the engine
submitted for the acceptance inspection complies with the type of design and corresponds to the requirements specified for the given type of engine. If the motor is satisfactory, its preservation and packing is carried out and it can be shipped to the final user.

Flying laboratory

For engine testing test flights, PBS purchased a L-13 Blaník glider which was converted into a so-called flying laboratory under the supervision of the Civil Aviation Authority (UCL). The plane was equipped with a measuring apparatus for engine data recording. The Blaník glider reached a respectable flight altitude record in 2008. It climbed (after disconnection from a hauling plane) up to the height of 9,700 m at tests of engine starting ability and operation in different altitudes. The flight tests brought a large quantity of valuable data which was used for consequent engine certification by the European Aviation Safety Agency EASA. This certification expired in 2014 when the PBS TJ100 engine obtained a type certificate as an auxiliary propulsion unit for gliders.