The Air Force views the mission of air superiority as instrumental for the success of other types of missions (deep strike, battlefield, interdiction, close air support, etc.). With the wide variety of current-generation fighters in the air forces of potential adversaries, as well as the potential sales of new-generation aircraft, the USAF will require a fighter able to engage and destroy any potential opponent at times and places of
Lockheed Martin indicates that the F-22A/B will be a true stealth design, in the same class as the F-117A and the B-2A. Although the F-22 is essentially the same size as the F-15, over the frontal aspect its radar cross section is reportedly over one hundred times smaller! The structure of the F-22 will be composed of the following: 28 % composites (carbon-carbon, thermoplastics, etc.), 37 % titanium, 20 % metal (aluminum and steel), and 15 % 'other' materials (kryptonite?). To reduce the weight of the aircraft and still provide strength, the structural members of the F-22 are of a mixed metal/composite design that minimizes the total RCS of the package. For example, two of every three wing spars are of composite construction, while every third one is titanium. Also, watch for a new paint which may have RAM properties as well. By the way, the 'notch' in the leading edge of the wing is supposed to be a radar 'trap' to catch and dissipate radar waves around the wing roots.
Even the engines are stealthy. Since the twin F119 power plants deliver enough dry thrust (i.e., without use of the afterburner) to allow the F-22 to cruise at supersonic speeds, its IR signature is significantly reduced over a conventional fighter aircraft traveling at the same speed. The Pratt & Whitney F119 (35,000 lb./15,909.1 kg. of thrust each) provides the F-22 with the performance of the F-15C (with the F100-PW-220 engine in full afterburner) while in military (dry) power. All this is done without a variable inlet ramp (to reduce the aircraft's RCS) and with an engine that is stealthy by itself, unlike those on the F-117A, which require inlet screens. The inlet ducts are curved to hide the fan section of the engine from enemy radar, with RAM and other engineering tricks to further reduce this traditional radar trap. On most jet aircraft the exhaust nozzles are round; on the F-22 they are rectangular slots, with movable vanes that can deflect the exhaust — in effect 'steering' the thrust vector. These '2-D' nozzles (up to +/-20deg of vertical displacement from centerline) of the F119 improve aircraft agility and give the F-22 superb short-field takeoff-and-landing performance.
The cockpit will be an almost totally 'glass' design (i.e., only MFDs), with only three analog instruments as emergency backups. No less than six multi-function displays of three sizes are arrayed for the pilot to configure as he or she pleases. The cockpit is a classic HOTAS design, with a wide-field-of-view holographic HUD. Also, a helmet-mounted sight for helping the pilots get weapons onto their targets is a likely upgrade. If the design for the F-22 works as planned, its flight envelope will vastly exceed that of any existing U.S. fighter, or even the MiG-29 or Su-27/35. Acceleration, rate of roll, and other control parameters are also planned to be superior on the F-22 when compared to existing designs. The quad-redundant, fly-by-wire flight control system is going to make the F-22 a true sustained 9-G airplane, able to rapidly turn and hold that load for as long as the pilot can stand it.
The F-22A/B will have the first fully integrated avionics suite ever flown on a combat aircraft. The Common Integrated Processor (CIP — the F-22 has two CIP bays, with room for a third) built by GM-Hughes is the core of the system and supports the Westinghouse-Texas Instruments APG-77 radar, the Lockheed Martin electronic warfare suite, and the TRW communications/ navigation/IFF subsystems. The electronics will be liquid-cooled, and they will run over one million lines of computer code. Total processing power for the F-22A/B with two CIP bays will be in the area of 700 Mips (700 million operations/sec — equivalent to four Cray supercomputers), with an expansion potential of something over 100 % already planned into the design.
As for sensors, the new Westinghouse APG-77 radar is a wide field-of-view (over 120deg) fixed phased array, which is virtually undetectable with conventional RWR systems. In fact, the APG-77 can probably be programmed to do virtually any kind of operation that a radar is capable of doing just by programming it with additional software and adding the necessary processor/memory capacity to the CIPs. Also, the F-22A/B will have an integrated countermeasures suite tied to the CIP bays. This will allow for rapid systems reprogramming in the event of a crisis, and should allow modifications to be handled quickly. The jammer/RWR antennas are contained in 'smart skins' on the wing tips, with the communications, navigation, and IFF antennas in the leading edges of the wings.
The basic weapons package of the F-22 will be roughly similar to that of the F-15C, though it will develop in stages. The missiles will be fired off hydraulically extensible rail launchers out of three internal weapons bays (one on either side, and one in the belly). Since opening a door to launch or fire a weapon may suddenly increase the RCS of the aircraft from certain angles, the designers have provided actuators that rapidly open and shut those doors, so that the exposure time is minimized. As an added stealth feature, the 20mm gun is buried deep in the right mid-fuselage area, and fires through a door that snaps open at the time of firing, then closes immediately after the last bullet passes. Also, in a non-stealth configuration, an additional eight air-to-air missiles can be carried on four wing pylons.
The F-22 has been designed so that most of the access panels are at ground level, and require only eight more tools than are already in the standard kit of the F-15C. Also, the F-22 will require a bare minimum of ground support equipment, such as service carts and workstands. For example, the F-22 has its own onboard oxygen and inert-gas generators to supply the environmental control system for the pilot and to provide pressurization for the fuel system. Thus, maintenance hours per flight hour should be even less than the F-16 or A-10. There also will be a portable electronic maintenance aid, based around a handheld computer, which will plug into the aircraft, and a maintenance laptop computer, which will do all the diagnostic work on what needs to be replaced, filled, or whatever. One of the design goals was to increase sortie rates by achieving a fifteen-minute combat turnaround time — that's to both refuel and re-arm!
While the final production number is still in flux, a figure of about $100 million is a fair estimate of what each F-22 will cost the taxpayers. In spite of this, the F-22 remains just about the highest-priority acquisition program that the USAF has today. It should keep the Air Force pushing the edge well into the next century.
Desert Storm: Planning the Air Campaign
Recently, the anniversary of Operation Desert Storm brought back memories of those incredible hours we spent glued to our televisions back in January of 1991 and the vivid images we saw: F-15s launching from Saudi runways; bombs dropping through windows; massed tanks crossing the desert; soldiers digging in on terrain that looked like Mars; ragged, dispirited Iraqi POWs trudging down roads littered with the wreckage of their army; those extraordinary sights of AAA bursts at night over Baghdad; and so much more. The media coverage of the war against Iraq was splendid. Yet when you think about it, for most of us the impression that remains is scattered, fragmented. Something is missing. What?
