The Strsljen multimission unmanned helicopter, developed by Serbian arms manufacturer EDePro, was unveiled during the International Defence Exhibition and Conference 2017 in Abu Dhabi, UAE.
The helicopter is primarily designed for use by the Serbian Armed Forces. It can perform various missions, including observation, monitoring, surveillance, reconnaissance, electronic countermeasures, and ground attack.
A mock-up of the Strsljen air vehicle was exhibited to the international markets during the Defense and Security 2017 Exhibition held in Thailand.
Strsljen unmanned helicopter design and features
The airframe of the Strsljen rotary-wing unmanned aerial vehicle (UAV) is built using carbon fibre, lightweight steel and aluminium materials. The UAV is 6.75m-long, 2.65m-high and 1.8m-wide. Its empty and gross weights are 400kg and 750kg respectively.
The rotorcraft takes-off vertically using a two-blade main rotor with a teetering head. The tubular skid landing gear is attached to the helicopter’s fuselage structure to facilitate safe landing even on hard surfaces. The main and tail rotor blades are built using high-strength, fibre-reinforced composite materials.
The helicopter’s modular design allows for carriage of payloads weighing 350kg, including sensors, fuel and armament.
It can be operated either manually by its operator from the ground control station or in autonomous mode.
An integrated autopilot system is installed to provide stabilisation and control for the helicopter in all axes. It will provide the UAV with the ability to fly in fully autonomous mode from take-off to landing.
Armament details of Strsljen
The unmanned helicopter is equipped with weapon pylons under the fuselage to carry air-to-surface weapons such as Spider anti-tank missiles and 12.7mm heavy machine gun.
The Spider fibre-optic guided tactical missile can be used to destroy heavily armoured fighting vehicles using tandem HEAT warhead.
Featuring high rate of fire capability, the 12.7mm weapon can hit surface-based enemy targets.
Sensors onboard Strsljen helicopter
The helicopter is equipped with a gimbal payload pod under the nose to carry sensor equipment for surveillance and observation missions.
Gyro-stabilised electro-optic (EO) and infrared (IR) imaging cameras are installed in the pod to provide day and night surveillance during combat operations.
The pod also carries observation radar to locate and track objects.
The rotorcraft is additionally integrated with an electronic warfare system to cause electromagnetic interference to the enemy’s radio communications during attack operations.
The Strsljen unmanned rotorcraft is powered by EDePro Phoenix-250DF turboshaft engine with a free turbine, which produces an output power of 230kW. The engine measures 720mm-long, 425mm-wide and 390mm-deep, and weighs 65kg. It has a compressor pressure ratio of six and turbine inlet temperature of 1,300K.
The engine’s gas generator rotates at a speed of 62,000rpm. The free turbine and output shaft speeds are 40,000rpm and 6,000rpm.
The standard and maximum fuel capacities of the UAV are 200l and 240l.
Performance of Strsljen UAV
The Strsljen unmanned helicopter has a cruising speed of 160km/h and a maximum flight speed of 180km/h.
It has a rate of climb of 8m/s and can reach altitudes of 4km. It has the ability to stay in the air for one to 3.5 hours, based on the mission requirements.
The drone can fly for up to four hours with maximum fuel.