Suppositions : futurs achats des FAR

The force structure demands required to defeat cruise missile armed aircraft, and cruise missiles once launched are similar, but the latter presenting greater demands both in fighter missile payloads and air intercept radar performance. Supersonic cruise missiles impose further demands on fighter dash speed and supersonic persistence. The conceptual model for cruise missile defence is the combined use of AEW&C, fighters, tankers and in many instances, airborne X-band surveillance radars to detect, track and engage both launch aircraft and cruise missiles.

A key issue in killing launch aircraft is the range of cruise missile being carried. A weapon which has 160 NMI of range offers good opportunities for the defender, especially if the AEW&C aircraft and CAPs can be positioned between the intended targets and known threat axis from which the opponent appears. Australia's JORN and the geography of the sea air gap are especially useful, providing the opponent does not exploit JORN blind periods to get a head start before detection.

These advantages decline with increasing ALCM range. A weapon in the 400 to 650 NMI range class presents opportunities to launch against a coastal target even if the AEW&C/CAP packages are orbiting well over the sea air gap. The upside for the defender is that a 60 to 90 minute ALCM flight duration presents excellent detection and repeat engagement opportunities.

Historically only two fighters were custom designed for cruise missile / bomber defence. The first was the US Navy F-111B, the second the MiG-31P Foxhound. It is no accident that both designs have similar empty weight, internal fuel load, high supersonic performance, huge radar bays, and carried similar payloads of similar sized AIM-54 and R-33/AA-9 Amos missiles.

Current US Air Force thinking on cruise missile defence envisages a two zone scheme. The outer zone comprises the E-3 AWACS, E-8 JSTARS / E-10 MC2A and the F-22A, and is intended to detect, track and kill launch aircraft and cruise missiles which might be launched. This outer zone is supplemented by an inner zone, comprising E-8 JSTARS / E-10 MC2A equipped with MP-RTIP X-band radars to track cruise missiles, and a mix of F-22A, JSF and AESA equipped F-15C/APG-82 or F/A-18E/F to destroy leakers which might penetrate the outer zone of F-22A defence. The US some years ago introduces fusing changes to the AIM-120C-6 AMRAAM to improve its ability to kill cruise missiles.

The limited look-down performance of the E-3 radar forces the use of the E-8 JSTARS as a gap-filler. The more capable E-10 MC2A was to later absorb most of this role, but was cancelled for budgetary reasons. The heavy reliance on the F-22A in the US model is a direct consequence of the F-22A's exceptional X-band radar performance and supersonic persistence, which allows it to patrol a much larger footprint than a conventional fighter does, and its ability to operate in contested airspace. The performance of the APG-77 permits head on engagements, and after passing the targets the F-22A would reverse heading for a repeat pass against any surviving cruise missiles.

The US Air Force envisage attackers launching waves of cruise missiles, the aim being to deplete fighter missile payloads and fuel, to create openings for a following wave of cruise missiles. The two zone model provides a mechanism to stop a second wave while outer zone interceptors are replenished.

Current long term planning for the RAAF leaves Australia in an invidious position as regional ALCM/SLCM capabilities develop over the coming decade. While JORN and Wedgetail provide excellent outer zone defensive capabilities, JORN blind periods and Wedgetail numbers will remain as real problems. The absence of a JSTARS-like capability seriously limits inner zone surveillance and tracking capabilities, especially against SLCM threats, constraining locations of Wedgetail orbits to cover both outer and inner zone areas.

The bigger hole in RAAF capability however lies in the plan for a lightweight fighter fleet, centred in F/A-18A and later JSF, with minimal tanker support. The F/A-18A and JSF are not F-22As in radar capability, missile/fuel payload or supersonic persistence.

Sadly, the plan to kill off the F-111 deprives the RAAF of a very economic inner zone cruise missile defence interceptor airframe, and long range bomber interceptor. The combination of persistence and supersonic dash performance, and large payload, provides the F-111 with the ability to cover inner zone patrol areas without tanker support, in an environment where its lack of close-in air combat agility is irrelevant. An F-111 can orbit on station 200 nautical miles from a runway for about 4 hours without refuelling, simply impossible for an F/A-18A or JSF. Retrofitting a suitable radar like an APG-79, APG-80 or APG-81, a JTIDS terminal and clearing the AMRAAM are relatively cheap given the return on investment, especially in reduced tanker demand and supersonic intercept capability against any fast bombers - regardless of resulting gains in F-111 strike capability.

In perspective, growth in regional cruise missile and long range bomber capabilities are now an inevitability. The big question which remains is whether Defence will make any effort to address the changing environment in RAAF force structure planning. Recent public statements are anything but encouraging.