Four Northrop Grumman RQ-4 Block 30 Global Hawk surveillance aircraft should be delivered to South Korea between 2017 and 2019, acting as a primary sensor in the country’s preparations to hit North Korean missiles before launch.

A contract from the U.S. government is likely in 2014, following an intergovernmental agreement by the end of this year, Northrop Grumman officials say, although the South Korean defense ministry expects the intergovernmental contract in the first half of next year. Under the Foreign Military Sales process, which is compulsory for the RQ-4, the U.S. government will supply the unmanned aircraft.

South Korea expects to pay 900 billion won ($850 million) for the acquisition program. The defense ministry says it expects to “adopt” the Global Hawk in 2017; Northrop Grumman sees deliveries being complete by 2019.

The aircraft will be delivered with equipment for imaging but not signals intelligence, though weight and space is available for the latter should South Korea want it and the U.S. agrees to supply it. As supplied, the system matches the U.S. Air Force’s imaging-only Block 30 Global Hawks. “There is no dumbing down,” Drew Flood, Northrop Grumman’s international program manager for the system, said at the Seoul International Defense & Aerospace Exhibition last week.

South Korea has sought Global Hawks since 2005 and formally asked the U.S. in 2009 to supply them. They will fill a requirement called Hovering Unmanned Aerial Vehicle (HUAV), while South Korea separately works on a medium-altitude unmanned surveillance aircraft, the Miniature Unmanned Aerial Vehicle (MUAV). One obstacle to the supply of Global Hawks has been the Missile Technology Control Regime, but the U.S. government has decided that the informal international understanding, limiting the export of long-range missiles and unmanned aircraft, did not apply to the Global Hawk.

South Korea’s program includes two ground stations. Since one station would normally be at the operating air base, handling takeoffs and landing, that suggests that the South Korean air force is planning to normally maintain one patrol with the capability to add another. The South Korean air force operates RC-800s, electronic intelligence aircraft based on Hawker 800 business jets, from the Seongnam base south of Seoul. But the runway there is only 55 km from North Korea, which has S-200 surface-to-air missile systems capable of reaching much greater distances.

Patrol stations near North Korea cannot be more than about 1,000 km from any South Korean air force base. So four aircraft, each with a range of more than 18,000 km and an endurance of 36 hr., are not needed to maintain one continuous patrol; allowing for overhauls, three would probably do. Instead, the order for four seems to be based on the unstated service-life goal. The Global Hawk airframe is designed to fly for 40,000 hr., so four could serve for a theoretical 18 years even if one were always aloft.

The Global Hawk’s synthetic aperture radar is of particular value to South Korea because the Korean peninsula’s mountain mists obscure military activity from visual sensors. South Korea’s recently announced Kill Chain policy evidently envisions detecting North Korean preparations for a missile launch and rapidly knocking out the weapon before it can be fired. South Korea does not seem to have said explicitly that it would act pre-emptively, but pre-emption must be inferred to give meaning to recent remarks by President Park Geun-hye that she will make North Korea realize that nuclear weapons are useless.

But with neither advance surveillance satellites nor suitable radar aircraft, South Korea’s ability to independently monitor North Korean ground activity is quite limited. It clearly depends mainly on U.S. intelligence. The Global Hawks will transform that situation. “This is a South Korean-controlled asset,” says Richard Weir, Northrop Grumman’s director of business development.

For Northrop Grumman, engineering work on South Korea’s program will be largely limited to replacing obsolescent parts in the ground equipment. Under offset contracts, local suppliers will make wiring harnesses and machined parts for all Global Hawks, not just South Korea’s. The government will nominate the suppliers, presumably with an eye on developing local industrial capability, but Northrop Grumman says they will have to meet expectations for price and quality.

Probably more important to South Korea will be technology transfer from Northrop Grumman. That will include training and modeling techniques for simulations as well as advice on airworthiness certification of unmanned aircraft. That will be particularly relevant to the development of the propeller-driven MUAV and its proposed high-altitude derivative. Little information on development of the indigenous aircraft has been available, but the program has been troubled. The MUAV airframe is adaptable to jet propulsion for operation closer to the Global Hawk’s altitude above 60,000 ft. (18,200 meters).