Piotr Butowski reports on the appearance of the Russian Sukhoi S-70 Okhotnik unmanned combat air vehicle
AT THE end of January 2019, the first photos of a new Russian heavy unmanned strike aircraft, the Sukhoi S-70 Okhotnik, appeared on Russian internet sites. The photos were taken this winter at the Sukhoi production facility airfield at Novosibirsk, where an S-70 technology demonstrator was built, and where taxi trials began in November 2018. Flight trials could begin in the coming months.
Work on the URBK (Udarno-Razvedyvatelnyi Bespilotnyi Kompleks or Strike- Reconnaissance Unmanned System) codenamed Okhotnik (Hunter) started on October 14, 2011. On that date, the Russian MoD ordered Sukhoi to develop and construct a long-range, high-speed strike-reconnaissance unmanned system demonstrator. Within the Sukhoi design bureau, the UCAV is designated the S-70 and represents the main design activity for the bureau after it completed development of the Su-57 fighter.
The S-70 Okhotnik is a 25-tonne UAV in an all-wing configuration and powered by a single jet engine; judging by the photographs released, the engine has an afterburner.
On February 24, 2018, Russian TV channel Zvezda, affiliated to the MoD, broadcast a large report in which Alexander Nemov, deputy department chief of the Russian Air Force Central Scientific Research Institute said: “Work on an unmanned long-range system, capable of autonomous low-altitude flight at supersonic speed and capable of engaging fixed and moving targets at operational and strategic distances is being carried out.”
Nemov was undoubtedly referring to the Okhotnik. Puzzling in his statement was reference to the air vehicle’s capability to fly at supersonic speed; it was previously believed the Okhotnik, like other heavy UCAVs, operates at high subsonic speed. However, the afterburner fitted on the demonstrator shown in the released photos confirms a capability to accelerate the air vehicle to supersonic speed, most likely for a short duration when transiting an enemy’s air defence zone.
The S-70 was constructed using elements of the new-generation Su-57 fighter; its landing gear is very similar to the Su-57 but probably a lighter version, in accordance with the air vehicle’s lower weight.
Okhotnik design most likely includes an AL-41F1 engine, also used by the Su-57, two internal weapon bays likely to be similar in size and design to those used on the Su-57 which measure 4.5m (14.8ft) in length and about 1m (3.3ft) in width. That is, the Okhotnik carries the types of weapon developed especially for the Su-57, for example, four anti-radar Kh-58UShK missiles, four universal air-to-ground Kh-38M missiles or four KAB-250 or KAB- 500M guided bombs.
Some tests within the Okhotnik programme are being conducted on T-50-3, the third Su-57 prototype, quite likely for evaluation of autonomous navigation and automatic take-off and landing systems developed for Okhotnik.
Over ten years ago and prior to the Okhotnik programme, several other Russian heavy UCAV projects were known. In 2007, RSK MiG showed a full-scale mock-up of the all-wing Skat (Ray) air vehicle that reportedly weighs 10 tonnes, reaches a maximum speed of 430kts (800km/h), with a range of 2,150 nautical miles (4,000km). In 2006, the Yakovlev design bureau presented the 10-tonne Proryv-U (Breakthrough) UCAV design, which was designed to reach a speed of 590kts (1,100km/h), offer a six-hour endurance and a 3-tonne weapon payload.
Even further back in the midst of the 1960s, the Soviet Air Force operated the very large Tupolev Tu- 123 Yastreb (Hawk) reconnaissance drone weighing 38.5 tonnes and with a speed of Mach 2.5; 52 air vehicles were manufactured. Yastreb was a single use system; only the nose part housing the reconnaissance sensors was recovered. Due to its huge cost, the Tu-123 was soon replaced with the manned MiG-25R reconnaissance aircraft.
