Although South Korea has been seeking Northrop Grumman RQ-4 Global Hawks for eight years, the unmanned surveillance aircraft is now becoming all the more crucial to its strategy of dealing with the threat from Pyongyang. North Korean attacks on the south in 2010, combined with the mounting nuclear danger, have led Seoul to seek an ability to stop strikes before they are launched. The Global Hawk is now seen as a primary sensor for cueing a preemptive attack.

Four RQ-4 Block 30s should be delivered to South Korea in 2017-19; the dates are uncertain. A contract from the U.S. government is likely in 2014, following an intergovernmental agreement by the end of this year, say Northrop Grumman officials, 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 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 forecasts deliveries in 2018-19.

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. agree 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 late last month.

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 HUAV while South Korea separately works on a medium-altitude unmanned surveillance aircraft, the 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, does not apply to the Global Hawk.

The UAV's synthetic aperture radar is of particular value to South Korea because the peninsula's mountain mists obscure military activity from visual sensors. South Korea's recently announced Kill Chain policy (or capability objective) evidently envisages 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 preemptively, but it 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.

Kill Chain was developed in response to two North Korean attacks on South Korea in 2010: the torpedoing of a warship and, more relevant to radar surveillance aircraft, the artillery bombardment of an island. The recklessness and aggression underscores fears of North Korea's nuclear capability.

With neither advanced surveillance satellites nor suitable radar aircraft, South Korea's ability to independently monitor North Korean ground activity is quite limited; however, it 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. The nearest U.S. Global Hawks are on Guam.

The preemptive attack would be mainly an army and navy mission, using surface-to-surface ballistic and cruise missiles, says Yang Uk, a senior researcher at the Korean Defense & Security Forum, a think tank. Aircraft without long-range standoff missiles would have to wait for the North Korean air-defense system to be knocked out, by which time the opportunity for preemption would have passed. South Korea is investing very heavily in indigenous surface-to-surface missiles (AW&ST May 21, 2012, p. 27). The ballistic variety would offer the fastest response time.

Even the enthusiasm of the South Korea air force (Rokaf) for intelligence, surveillance and reconnaissance (ISR) seems doubtful, says Yang. “Since the most important factor of the so-called Kill Chain is the sensor, the role of the Rokaf is important with its ISR assets. But the problem is that the [air force] leadership is so focused on fighter programs such as F-X Phase 3 and KF-X,” he notes. “And the current fiasco in F-X gives little room for the leadership to take interest in other programs, such as Global Hawk.” South Korea is reevaluating its F-X Phase 3 program for 60 fighters.

Current ISR assets such as RF-4, RF-5 and RC-800 aircraft have no real-time capability, a critical problem if rapid preemption is required. Yang thinks the Korea Defense Intelligence Command should lead all national ISR programs.

South Korea's Global Hawk order will include two ground stations. Since one would normally be at the operating air base, handling takeoffs and landings, that suggests that the country's 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 (34 mi.) from the territory of North Korea, which has S-200 surface-to-air missiles 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 range of more than 18,000 km and 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.

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. Those issues are 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 is known to have hit its fair share of troubles. The MUAV airframe is adaptable to jet propulsion for operation closer to the Global Hawk's altitude above 60,000 ft.