Saab rotary UAV casts off for sea duty

 - November 11, 2007, 6:57 PM
As if fully autonomous UAV operations didn’t present enough of a challenge, Saab Aerosystems is developing one of its unmanned systems to operate at sea. The Skeldar M is a version of the company’s V-150 Skeldar (shield) rotary-wing UAV intended for operation from a variety of vessels. Work is progressing toward automatic deck landing trials in June 2008, followed by Swedish Navy tests later in the year. The company places its in-service target at 2009.
At 175 kilograms empty the Skeldar M weighs more than its land-based cousin as a result of the ‘marinization’ that requires a sturdier structure to cope with heavier landings, and additional coatings to protect the vehicle in a maritime environment. However, it can also carry a heavier payload within its 250-kilogram maximum takeoff weight.
On a typical mission with fuel for an endurance of five hours, Skeldar M can carry a 40-kilogram load, considerably more than the land-based Skeldar. In practical terms, that translates into the M’s ability to carry two payloads–for example, EO/IR and radar–rather than one. The radius of action is typically 180 kilometers with line-of-sight datalink.
Anders Carp, Saab’s director of UAV Systems, outlined the intended roles for Skeldar M during the AUVSI Unmanned Systems Middle East conference here in Dubai. Important tasks include sea traffic control and identification, the Skeldar M effectively increasing the parent vessel’s surveillance horizon. With a radar payload the UAV allows the vessel to conduct its task while remaining radar-silent itself. The capability lends particular application to the ‘Visby’ class of stealth corvettes operated by the Swedish Navy. Other roles include reconnaissance ahead of littoral and amphibious assault operations, target designation for naval weapon systems and littoral/maritime disaster damage assessment.

Along with facing the traditional maritime challenges of protection against salt corrosion and conquering the effects of spray, the Skeldar M team is addressing the problems of shipboard storage, especially on the ‘Visby’ corvettes, where space is short and where stealth requirements rule out external storage.

Another factor involves the need to integrate the UAV control and surveillance system into existing ship-based systems. Far more challenging, of course, is the requirement to safely and reliably recover the UAV to a pitching deck on a moving ship. Considered a truly autonomous vehicle, Skeldar must take off and land at the push of a button. 

Debate continues as to whether the automatic recovery ‘intelligence’ should be based on the ship or in the UAV. Saab is initially targeting an autonomous recovery capability in sea states up to 4, later increasing to sea state 5.