Maritime patrolling with UAVs has becoming the norm, allowing manned missions to be dedicated to more mission specific tasks.
Airborne maritime operations such as anti-submarine warfare (ASW), intelligence, surveillance, and reconnaissance (ISR) and patrol missions have typically been the province of multi-engine aircraft specifically designed for extended overwater operations or commercial platforms modified for such operations.
However, the means of acquiring and maintaining adequate fleets of such manned platforms remain beyond what some Asia Pacific countries – including maritime states with large economic exclusive zones (EEZs) and contiguous waters to secure – can field by their respective air and naval forces and maritime security agencies.
As a result, there is a growing requirement for affordable alternatives to conventional ISR and maritime patrol aircraft (MPA) which the unmanned aerial vehicle (UAV) industry hopes to address with medium- and high-altitude, long endurance (MALE and HALE) platforms with their long range and loiter capabilities as well as their inherent to carry multiple sensor payloads simultaneously.
At the other end of the spectrum are smaller fixed-wing and vertical take-off and landing (VTOL) UAVs, which are also gaining favour as shipborne ISR assets that can be readily deployed to extend a surface vessel’s detection range.
Israel’s Elbit Systems has developed a maritime patrol mission suite for its Hermes 900 UAV, which can comprise a synthetic aperture radar (SAR) such as Leonardo’s Gabianno T200 X-band radar, a stabilised electro-optical/infrared (EO/IR) turret and electronic surveillance systems.
According to Elbit’s specifications, the Hermes 900 has a maximum take-off weight (MTOW) of up to 2,600lb (1,180kg) and can carry 660lb (300kg) of mission equipment. This includes up to 550lb (250kg) of internal stores in its 2.5m-long payload bay, which the company believes to be among the largest available for its class.
Elbit Systems has also stated that its Universal Ground Control Station (UGCS) can simultaneously control two Hermes 900 UAVs to maximise asset utilisation and manpower, while reducing overall operating costs.
The Hermes 900 has met with a recent string of successes in Europe. For instance, the European Maritime Safety Agency (EMSA) has been used to provide maritime patrol services to on a daily rotation since April 2019, with Iceland being the first country to take advantage of this service. According to Elbit Systems, the Icelandic maritime authorities are using the eastern Egilsstaðir airport from which the UAV – modified to withstand the North Atlantic Ocean’s strong winds and icy conditions – can cover over half of the country’s EEZ.
The Hermes 900 has also found regional traction with at least two of the nine air vehicles – ordered under a $153 million package that includes other UAVs such as the Hermes 450 and Skylark – already delivered and undergoing local testing and integration by the Philippine Air Force (PAF).
Defence Secretary Delfin Lorenzana told media that the Hermes 450 and Hermes 900 UAVs are expected to be operated from airbases in Palawan province facing the South China Sea as well as in the southern province of Mindanao.
More recently, Elbit Systems announced in February that it has been contracted by the UK’s Maritime and Coastguard Agency (MCA) to supply several UAV’s including the Hermes 900 to explore the feasibility of supporting search and rescue (SAR) operations. The MCA will commence evaluations from West Wales airport within 2020, while the maritime missions will be conducted within the Aberporth military training area.
One of the main objectives, according to MCA officials, will be to validate the effectiveness and safety of UAVs and pave the way for Civil Aviation Authority (CAA) permission to operate these systems in unrestricted airspace.
Heron Fishes for Subs
Israel Aerospace Industries (IAI) has introduced a new ASW capability to its Heron MALE UAV family. The company said it has developed a new sonobuoy dispensing system (SDS) and a magnetic anomaly detector (MAD) which enable air vehicle to detect and track submarines in both shallow and deep waters.
These new payloads complement the Heron’s primary surveillance sensor, the IAI ELTA E/LM-2022U maritime radar which is lighter and more compact version of the E/LM-2022 system already deployed aboard MPAs around the world. According to IAI, the E/LM-2022U can cover up to 150 nautical miles (nm) of water from a cruising altitude of 20,000 feet (6,100m)
“The use of UAV-mounted ASW capabilities offers significant advantages over conventional manned aircraft, including longer mission time, persistent monitoring of sonobuoys, and centralised operation of surveillance over very large areas,” the company stated.
According to IAI, the radar – which it claims can detect and classify “all types” of surface targets from large vessels to low radar cross section (RCS) boats using inverse-SAR mode – can be complemented by electronic support measures (ESM) and communications intelligence (COMINT) systems to monitor electromagnetic signatures and cue the radar to the presence of vessels and human activity.
“The ELM-2022U can spot submarine periscopes and snorkels from a great distance,” the company added, noting that the UAV would engage its SDS and loiter over an area to receive and process acoustic signals generated by deployed sonobuoys, cross referenced with data from its MAD probe, radar, and EO/IR sights. The intelligence is then transmitted to a shore-based control centre or a ship’s combat information centre (CIC) using satellite communication (SATCOM) or direct line-of-sight (LOS) datalinks.
IAI is also highlighting how Heron UAV mission control modules, including stabilised directional antennas and SATCOM terminals, can enable naval vessels to take over control of in-theatre UAVs to as part of their organic sensor net to boost situational awareness.
The Chinese Perspective
The People’s Republic of China (PRC) is widely seen to be one of the leading regional developers of maritime-specific UAVs, having deployed such platforms operationally for at least a decade. For instance, the interception of a Chinese air vehicle – since identified to be the MALE-class Beijing University of Aeronautics and Astronautics (BUAA) BZK-005 – by Japan Air Self-Defense Force (JASDF) combat aircraft over the East China Sea on 9 September 2013 provided the first glimpse of the People’s Liberation Army Air Force (PLAAF’s) emerging long-range unmanned maritime surveillance capabilities.
According to the Japanese Ministry of Defense (MoD), the JASDF aircraft tracked the UAV heading towards the Miyako strait between Okinawa and Miyakojima islands before the air vehicle performed a short circular patrol about 92nm (170km) shy of the waterway before returning to China.
The indigenously developed BZK-005 UAV – also known as the Changying (Long Eagle) – is understood to be the standard long-range reconnaissance and electronic intelligence (ELINT) platform for the PLAAF as well as the PLA Ground Force (PLAGF) and PLA Navy (PLAN).
According to Beihang UAS, the commercial arm of BUAA, the distinctive airframe of the BZK-005 comprises a main fuselage that incorporates a top-mounted satellite communications antenna fairing, with swept back mid-mounted wings that support twin tailbooms.
Company specifications, the BZK-005 has maximum take-off weight (MTOW) of 2,755lb (1,250kg) and offers a payload carrying capacity of 330lb (150kg). The UAV is powered by a rear-mounted piston engine that drives a two-bladed pusher-propeller that enables it to attain a claimed maximum level flight speed of 107kts (200km/h) although it typically cruises at speeds between 64-97kts (120-180 km/h) up to its ceiling of 24,000ft (7,300m). Operational radius is believed to exceed 1,000 nautical miles (1,850km) when equipped with SATCOM datalinks.
Beihang UAS is quoting a flight endurance of 40 hours when the BZK-005 is configured as a maritime ISR platform with a chin-mounted EO/IR sensor turret, although it has also been sighted over the years with a chin-mounted SAR system along with a belly mounted EO/IR turret, or studded with COMINT/ELINT antennas.
The company launched an export variant called the BZK-005E in late 2018, which features a higher MTOW of 3,300lb (1,500kg) and improved payload capacity of 815lb (370kg) and is understood to feature a more powerful, three-bladed propulsion system. It has also developed the TYW-1, a strike-capable version of the BZK-005 with four underwing hardpoints that can be used to mount weapons.
The state-owned China Aerospace Science and Technology Corporation (CASC) is likewise developing a new heavy fuel engine (HFE)-equipped variant of its Cai Hong 4 (Rainbow 4, or CH-4) MALE UAV for potential maritime operations, noting that such propulsion configurations can offer extended on-station loiter while reducing maintenance workloads.
The CH-4 has been acquired by military forces in the Middle East and even Southeast Asia, with the Indonesian Air Force (TNI-AU) set to receive as many as six conventionally powered air vehicles along with associated ground control equipment and mission systems. At least two examples have already been delivered as of October 2019.
Regional interest in VTOL UAVs has also taken off largely due to a growing requirement to equip new naval and even maritime security vessels with an organic and readily deployable offboard sensor platform to aid situational awareness and/or targeting.
Unlike shipborne fixed-wing UAVs such as the Boeing-Insitu ScanEagle system that must be launched by a catapult and recovered via an arresting cable or net (which potentially limits their recovery envelope), VTOL UAVs typically require much less deck space and are therefore easier to operate from smaller vessels.
Austria’s Schiebel has gained a foothold in the region with its S-100 Camcopter platform, which has been acquired under the Australian Department of Defence’s (DoD’s) Navy Minor Project (NMP) 1942 programme aimed addressing a shipborne UAV requirement by the Royal Australian Navy (RAN).
The S-100 has a MTOW of 440lb (200kg) and features a two-blade main rotor with a diameter of 3.4m and streamlined carbon fibre monocoque pod and boom fuselage. According to company specifications, the UAV can carry up to 110lb (50kg) in stores along with 110lb (50kg) of fuel and is understood to offer a six-hour endurance when carrying a 74lb (34kg) payload, although this can be extended to 10 hours with an external fuel tank.
This effort is expected to lead on to Project Sea 129 Phase 5 Stage 1, which will field a suitable UAV aboard the RAN’s 12 Arafura-class offshore patrol vessels (OPVs), the first two of which are being built by ASC under the direction of prime contractor Lürssen. Phase 2 will select another UAV type to equip the nine future BAE Systems Hunter-class frigates.
The RAN’s S-100 UAVs are believed to be equipped with L3Harris Wescam’s MX-10 EO/IR payload, which can support up to six sensors simultaneously including high-definition daylight and thermal cameras. It can also be equipped with an eye-safe laser rangefinder to aid targeting.
To boost the S-100’s maritime surveillance capabilities, Schiebel has integrated Overwatch Imaging’s PT-8 Oceanwatch wide-area maritime surveillance payload which is designed to detect small or distant objects. According to the latter, the PT-8 system employs a purpose-built multi-camera gimbal with onboard artificial intelligence (AI) software that automatically detects and tracks objects of interest.
Schiebel announced in November 2019 that it has secured a deal to supply an undisclosed number of S-100 UAVs to the Royal Thai Navy (RTN).
“Following an extensive competitive tender process, Schiebel was awarded its first contract with [Thailand], which was signed by Schiebel’s CEO Hannes Hecher and Admiral Prachachart Sirisawat, director general Naval Acquisition Management Office, and authorised by [the] Commander-in-Chief of Royal Thai Navy Headquarters in Bangkok,” the company said, noting that the S-100 will be the service’s first VTOL UAV.
According to Schiebel, the UAVs will be deployed in 2020 to the Pak Phanang district in the southern Nakhon Si Thammarat province, as well aboard RTN frigates to support land- and sea-based ISR operations. The company said it will supply the UAVs and effect technology transfer via its local partner, the Bangkok-based MoraThai Defence Company.
Switzerland’s UMS Skeldar is also looking to leverage on its recent successes with the Canadian Armed Forces and the German Navy with its V-200B VTOL UAV to secure its first customer in the Asia Pacific.
The latest V-200B platform has a MTOW of 518lb (235kg) and features a 4m long pod and boom fuselage with a two-bladed main rotor measuring 4.6m in diameter, a belly mounted payload bay and fixed twin-skid undercarriage. The V-200B features a lighter propulsion system that provides up to 22lb (10kg) in weight savings, which can be applied to either increase its endurance or payload capacity.
For the maritime mission, UMS Skeldar has integrated Sentient Systems’ visual detection and ranging (ViDAR) payload, which is a persistent wide-area maritime sensor that automatically detects objects on the ocean surface and provides the operator with detailed imagery and location coordinates of surface objects. According to Sentient Systems, the ViDAR offers a 20nm (37km) wide search swath, equating to over 13,360 square nautical miles of cover in 12 hours at a speed of 60kts (111km/h).
by JR Ng