Nonetheless, questions remain over the F-35's cost and reliability, and in South Korea are exacerbated by Boeing's strong position as the supplier of the F-15K Slam Eagle. The F-15K won FX-I and FX-II, supplying 61 aircraft to the Republic of Korea Air Force (RoKAF) and building a solid reputation for interoperability, firepower and deep strike capabilities that would serve Seoul well against a North Korean attack. The Eurofighter, meanwhile, came out of the 2011 Libya conflict with its combat credentials enhanced and is gradually developing into a true multi-role aircraft.
Whichever aircraft wins the competition, the reality is that the capability gap between North and South Korea's air forces has been growing for years. Estimates by IHS Jane's reckon that North Korea has only 35 or so MiG-29 'Fulcrum' air-supremacy fighters in service, alongside about 260 obsolete MiG-21 'Fishbeds' and MiG-19 'Farmers' that would provide little more than target practice for the RoKAF's Lockheed Martin F-16C/D fighters and the FX-III winner.
That is not to say that the threat is not there. Randy Howard, director of F-35 Business Development activities for the Republic of Korea, points to North Korea's "integrated air defense system … that does not allow South Korea, with its current assets, to penetrate and hold those strategic targets at risk." According to Howard, that's where the F-35 comes in. "What 5th generation aircraft do is give you proactive strategic deterrence. It’s the ability to penetrate heavily defended airspace and hold targets of interest at risk any time you want to. That’s what the F-35 can do because it’s stealthy, it’s really stealthy," he says.
Howard also points out that North Korea notwithstanding, Northeast Asia is a dicey neighborhood. “China and Russia are developing stealth fifth-generation fighters,” say Howard. “South Korea has to decide: is fourth generation OK for us or do we have to move to fifth generation with the rest of the world?”
The difference between a modern fourth-generation fighter such as a new-build F-15 or Typhoon and a fifth-generation fighter such as the F-35 is a matter of some conjecture, but in layman's terms comes down to one key factor: stealth.
And as Howard makes clear, stealth is at the heart of Lockheed Martin’s sale pitch. “The fact is, if you want a stealthy airplane, a truly stealthy airplane, you have to design that in from the very beginning,” says Howard. “You cannot take an existing platform, a fourth-generation non-stealthy platform, and make it stealthy for the 21st century in a way that the fifth-generation F-35 and F-22 do.”
Boeing, unsurprisingly, sees it differently. The F-15SE includes structurally stealthy features such as radar absorbing material, angled vertical tail fins and conformal fuel tanks and weapons bays that go some way to reducing its radar cross section, or RCS. Meanwhile, Howard Berry, Boeing’s FX-III campaign manager, says that stealth, or radar signature, “is but one element” of a concept that he calls “balanced survivability” that also includes the F-15's electronic warfare (EW) suite and its advanced AESA radar (both of which the F-35 also fields).