Delays to the Joint Strike Fighter program and uncertainty over acquisition and support costs have ruled out one-for-one replacement of inventory fighters in the U.S. fleet for well over a decade. Half of the U.S. Air Force fighter force in 2030 will comprise conventional aircraft, according to current fleet plans outlined to Congress, and slated F-35C numbers and acquisition rates are being questioned at the highest levels of the U.S. Navy.
Outside the U.S., South Korea appears likely to select the F-15 Silent Eagle for its next fighter buy this summer, deferring stealth to Block 2 of its planned indigenous KF-X fighter. The most recent U.K. National Audit Office report on the British carrier and JSF program suggests that the plan to replace the Tornado with 90 F-35s (on top of the 48 aircraft that will be acquired to arm the nation's new aircraft carriers) has been slipped well past 2030.
When the Joint Strike Fighter program was kicked off in late 1996, it was intended not only to be stealthy, but to match or surpass any other across the full range of fighter missions (with the exception of the F-22 in air dominance) while costing less to acquire and support than the F-16. The business plan envisioned a near-complete takeover of the global fighter market with an initial operational capability (IOC) in or soon after 2010.
Competitors are preparing marketing offensives on the basis of a different vision of how stealth should be used, based on the fact that three classes of stealth technology have been defined.
The F-35, F-22, Sukhoi T-50, Chengdu J-20 and Shenyang J-31 occupy a middle range, designed to present a low radar cross-section (RCS) to most airborne radars and many surface-based acquisition and tracking radars, with the lowest RCS from the frontal aspect and the highest at the tail. The F-35 and F-22, at least, make minimal if any use of active electronic warfare (EW).
The second class includes almost all current combat aircraft. They feature RCS-reduction measures including fundamental shaping attributes (the Eurofighter Typhoon, for instance, has full line-of-sight protection of its engine faces with serpentine ducts), details such as the Rafale's saw-tooth appliques and RCS-tailored refueling probe, and radar-absorbent materials. They also include jamming systems.
The third group is an expanding range of prototypes and developmental aircraft with ultra-low RCS over a broad bandwidth and full range of aspect angles. These include the Northrop Grumman X-47B, the classified intelligence, surveillance and reconnaissance UAV being developed by the same company for the U.S. Air Force, Europe's Taranis and Neuron, and the Chinese UCAV seen in ground tests in May.