Garry

Some people are not good opponents to argue with. Blind minds. Imagine that you're are not blind and try to explain something to them? Waste of time. This forums are good only when you can learn something....

Lets admit. There are many people like this in many nations.... I live in Moscow now and morons are available here just like anywhere else.... I lived in NY and it is full of crazy people. I never bother giving them idea who they are whereeve meet them.

Horrido

Holster the insults, folks. All it does is waste people's time having to wade through the BS. Name-calling only demonstrates you don't have what it takes to either get your point across or support your position. Being offended is a choice, and I have a MUCH higher regard for thick-skinned individuals that can fight past the fire with discipline intact. Like I've been trying to get through to folks, post the data, cite the source, take a step back (think of it kinda like a legal case in court ). Otherwise, just accept the fact that you can lead a horse to water... and let the merry in-DUH-vidual continue on in ignorant bliss.

__________________
The black flag is raised: Ban them all... Let the Admin sort them out.

I know I'm going to have the last word... I have powers of deletion and lock.

Rusky

I see your point exactly, i also live in Moscow by the way. The thing is that proportion wise more morons in US have internet access.

Defcon 6

Your right, it's about time I crushed Rooshoo and friends with facts and evidence.

Let this court commence-

Unfortunately there is no point to make here since the F-16 flies with the reserve anyways. The F-22 is a replacement for the F-15, not the F-16. So right off the bat you don't understand what your talking about in this case.

The F-15 specifications are as follows-
Variant C/D models E/F models
Primary Function Tactical fighter. Tactical Bomber
Contractor Boeing (McDonnell Aircraft and Missiles Systems) Boeing (McDonnell Aircraft and Missiles Systems)
Power Plant Two Pratt & Whitney F100-PW-100 turbofan engines with afterburners, each rated at 25,000 pounds engine ( 11,250 kilograms) two Pratt and Whitney FIOO-P-220 turbofans each rated at 14,670 lb st (65.26 kN) dry and 23,830 lb st (106.0 kN) with afterburning or,
after August 1991, two FlOO-PW-229 each rated at 17,800 lb st (79.18 kN) dry and 29,100 lb st (129.45 kN) with afterburning;

Length 63 feet, 9 inches (19.43 meters). 63 ft 9 in (19.43 m)
Height 18 feet, 8 inches (5.69 meters). 18 ft 5.5 in (5.63 m)
Wingspan 42 feet, 10 inches (13.06 meters) 42ft 9.75 in (13.05 m)
Wing aspect ratio 3.01
Wing area 608.00 sq ft (56.48 m2)
Speed 1,875 mph (Mach 2.5-plus). 1,433 kt (1,650 mph; 2655 km/h) maximum level speed 'clean' at high altitude
495 kt (570 mph; 917 km/h) cruising speed at optimum altitude
Ceiling 65,000 feet (19,697 meters). 60,000 ft (18290 m);
Operating Empty Weight 31,700 lb (14379 kg)
Maximum Takeoff Weight 68,000 pounds (30,600 kilograms). 81,000 lb (36741 kg)
fuel 13,123 lb (5952 kg) internal
21,645 lb (9818 kg) in two CFTs
up to three 610-US gal (2309-liter~ drop tanks;
Range 3,450 miles (3,000 nautical miles) ferry range with conformal fuel tanks and three external fuel tanks. 3,100 nm (3,570 miles; 5745 km) ferry range with CFTs and drop tanks
2,400 nm (2,765 miles; 4445 km) with drop tanks
1,000 nm (1,150 mi; 1,853 km) Max Combat Radius
685 nm (790 miles; 1270 km) combat radius

So right away your entire theory melts since the F-15 is 63.9 feet long compared to the F-22's 62.1

The F-16 is not an air superiority fighter. Your arguement has been crushed.



Rusky once again is wrong. Let me post a link to the insurmountable evidence.

http://www.globalsecurity.org/milita...laaf-intro.htm
http://www.globalsecurity.org/milita...hina/plaaf.htm
http://www.globalsecurity.org/milita...laaf-equip.htm


Yeah, your done. Go take a nap. China does indeed have the largest air force in terms of sheer numbers. China has some 4,000 fighter aircraft and 6,500 total aircraft. Making it the largest air force in the world.

The_Burning_Kid

Don't waste your times guys. This is the same person that can't say anything better than "your in denial" when he can't make a good counterargument. Its honestly funny. I wouldn't waste brainpower on someone like him.

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*If you clicked that you fell for it :tongue:

Defcon 6

Furthermore, lets have a review of the F-22 and it's capabilities.

If building an aircraft that has been described as "the only thing more complex than the human body" in five separate geographic locations wasn't challenge enough, the F-22 team also has to build an aircraft to tolerances on the order of ten-thousandths of an inch in order to meet its stealth requirements. Certainly not an easy assignment.

But the initial hurdles have been overcome. When the first F-22's fuselage was mated in the fall of 1996, the pieces went together just as the designers had predicted they would. Final mate of the forward fuselage that was made in Marietta, Ga., to the mid fuselage made in Fort Worth, Texas, and that mid fuselage to the aft fuselage made in Seattle, Wash., took only a few days to accomplish. The first shipset of wings was mated in less than 48 hours. The vertical stabilizers went on in less than a day. Between the two body mates and the wing joins, a total of 40 shims had to be generated, all about the thickness of a sheet of paper.

The Integrated Product Team (IPT) philosophy that the F-22 and F119 are being developed under has paid big benefits in the manufacturing area. The IPT concept has moved manufacturing from its traditional place down the schedule to up front with the designers. Manufacturers worked with designers and maintainers to ensure that a part or system was not only designed correctly, but it could be manufactured, and it could be maintained while that part or system was still on the drawing board.

While not a revolutionary idea, collocated IPTs does make good common sense. It improves communication and avoids problems and rework later on.

CATIA and COMOK

The computer revolution has changed the detail design process of the aircraft. With the IBM-Dassault Systemes-designed Computer Aided, Three-Dimensional Interactive Application (CATIA), the aircraft designer can design the parts of the F-22 as a solid object, not just lines on a flat page.

With COMOK (a team-developed computer mockup simulation), the designer can visualize every aspect of the design including complex routing for wires, tubes, and cables. There is no 'hard' mockup of the F-22.

These computer programs allow the design engineer and the manufacturing engineer actual look inside the structure before it is built.

More than just a visualization, the computer data that creates these images are precisely stored design measurements that can be transferred, again by computers, between the team's locations in Marietta, Ga., Fort Worth Texas, Seattle, Wash., and West Palm Beach Fla., and East Hartford, Conn. and supplier locations all around the country.

Parts of the aircraft fit remarkably well when received in Marietta, where final assembly takes place, even though no master tool was sent to trial fit the pieces. In fact more than 270 master tools have been eliminated as confidence in the 3-D tools grew. As part of the IPT process, the team found that it could hold tolerances to 1/6000 of an inch on parts.

Numerical Control (NC) Programming

The numerical control (NC) machines that mill the parts for F-22 use the same data set as the CATIA design tools, and there are no errors in translation between the two. So, by removing variation in the data set, one-half of the possibility of variation between parts is eliminated. The possibility of variation because of the machine fabricating the part remains, however.

Avionics Racks

The F-22's avionics have the computing power of two Cray supercomputers, and they produce a large amount of heat. The racks that hold the avionics are not only thermal management units - the F-22's avionics are air cooled, liquid cooled, and liquid flow-through cooled, they are also structural parts of the aircraft. The racks have to hold the modules in the correct position in the backplane and they cannot leak, even when the aircraft is maneuvering violently at forces up to nine-Gs.

More than 250 avionics racks had been built as of early 1997, out of a total of just under 300 racks necessary for the current Engineering and Manufacturing Development (EMD) phase of the program. The avionics racks are fabricated and assembled in Marietta, Ga.

Tooling

Unlike many other aircraft programs, where parts move from tool to tool, a majority of F-22 tools move with the part. This keeps the part from flexing or not being aligned properly when it is moved to the next tool in the assembly process.

The F-22 tooling is also designed to be as ergonomic as possible. The tools are elevated to allow workers to get under them without stooping and they are well lit. In final assembly, the workstands move on integral castors to allow them to be pushed easily against the aircraft.

The final assembly line in Marietta is sized for producing the EMD aircraft and the F-22s in the low-rate production lots. At high-rate production (48 aircraft per year), it will only be necessary to add duplicates of some of the existing tooling. The team's design goal was to build the first EMD aircraft as closely as possible to the first production aircraft

Composite tools for building composite parts are not durable, so the team opted to build Invar steel tools. This allowed for tools that can be reused over and over. The Invar tools contain all the necessary thermocouples for measuring the temperature of the part, and the necessary connections are also all in one place.

Of the composite parts produced for the first aircraft and those following after, as an example, Lockheed Martin Aeronautical System achieved a 90% usable first part yield, and 78% of the parts were defect-free. Most of the defects were found using non-destructive inspection (NDI) and could be corrected.

Aircraft Materials Composition

The aft fuselage of the F-22 is mostly high strength titanium, as it has to hold the aircraft's F119 engines, and it must be able to withstand the high temperatures the engines create. The mid fuselage transitions from titanium (in the larger, load-bearing bulkheads) to forged aluminum bulkheads and aluminum frames. The forward fuselage contains a composite fuel tank (the F-1 tank behind the pilot's ejection seat) and is made of machined aluminum. The wings are made of composite spars and skins with titanium reinforcement.

Assembly Processes

Two computerized systems that have been implemented at Lockheed Martin Aeronautics Company in Marietta are being utilized in the process of assembling the F-22, DASS and MATS.

The Dynamic Assembly Scheduling System (DASS) is a simulation of the entire factory. A manager loads in data - who is out sick, what tools are down for maintenance, etc. - and the system runs a simulation of the work day and it then resequences the work to what can be done on that particular day.

The Manufacturing Assembly Tracking System (MATS) is a television-sized monitor that allows the individual worker to call up the work task for the day and the system provides the instructions to accomplish it. The worker can look at diagrams of the procedure and can zoom in to look at specific parts. A temporary drawing can be printed if necessary, but the drawing is discarded at the end of the day. That way, only the most current drawing is used. The MATS terminal also serves as an electronic bulletin board, allowing workers to view current news, company staff meeting notes, etc.

In the Final Assembly Area, workers are not allowed to use the "own" tools. All of tools are shadowboxed in company-issued toolboxes and when a worker removes a tool, he or she places a chit with a photograph and the employee's number on it in the tool's slot. All of the tools are accounted for at the end of each shift and the boxes are locked until the next shift comes in. This eliminates the possibility of a tool being left in the F-22 and creating a Foreign Object Debris problem.

F-22 AIR VEHICLE COMPONENTS


Forward Fuselage and Empennage

Lockheed Martin Aeronautics Company in Marietta, Ga. builds the forward fuselage of the F-22. It consists of the structure aft of the radar bulkhead, the cockpit area, nose wheel well, and F-1 fuel tank. It consists of approximately 3,000 parts made mostly of aluminum and composite materials. The forward fuselage also contains wiring harnesses, tubing, cockpit instrument fixtures, avionics racks, and canopy mounts.

The F-22's forward fuselage is just over 17 feet long, slightly wider than five feet inches wide at its widest point, five feet, eight inches tall, and weighs roughly 1,700 pounds.

Built up in two sections, the forward fuselage is joined together by two long and relatively wide side beams and two longerons that run the length of the assembly. The beams, made of composite material, also provide an attachment point for the F-22's chine, a fuselage edge that provides smooth aerodynamic blending into the intakes and wings. The 17-foot-long aluminum longerons form the sills of the F-22's cockpit and the canopy will rest on them.

The canopy is also built up in Marietta, and is approximately 140 inches long, 45 inches wide, 27 inches tall, and weighs approximately 350 pounds. Seven test canopies were built for the sled test program.

The integrated forebody, also referred to as the radome, is composite. It is manufactured by Lockheed Martin Aeronautics Company in Palmdale, Calif.

The empennage consists of the vertical and horizontal tails. The verticals are a multi-spar configuration internally, and with a hot isostatic pressed (HIP) cast rudder actuator housing. The edges and rudder are made of composites., and both parts have embedded VHF antennas, as well as other antennas. The rudders can also be towed inward to act as a speedbrake for the F-22.

The horizontal surfaces, known as stabilators, are made of honeycomb materials with composite edges. They are all-moving assemblies and are deflected by the Composite Pivot Shaft (see CPS in Materials and Processes section).

Mid-Fuselage

The mid fuselage is the largest and most complex of the F-22 assemblies. It is approximately 17 feet long, 15 feet wide, and 6 feet high, and weighs approximately 8,500 pounds as shipped.

The mid-fuselage is considered the heart of the F-22 as almost all systems pass through this section, including the hydraulic, electrical, environmental control, and auxiliary power systems, as well as the aircraft's fuel. In addition, there are three fuel tanks, four internal weapons bays (the two side bays, and the two sections of the main weapons bay that is separated), the 20-mm cannon, and the auxiliary power unit (APU).

Mid fuselages of F-22 EMD aircraft are assembled in the north end of the Lockheed Martin Aeronautics Company in Fort Worth, Texas. Employees at the Fort Worth plant fabricate most of the composite parts and assemblies, tubes, and harnesses in the mid fuselage.

Most of the aluminum machined parts are made by Lockheed Martin Aeronauticsl Company in Marietta, Ga. Subcontractors spread throughout the United States supply titanium parts, standard hardware, and system components for the mid fuselage.

Lockheed Martin is using a modular approach to assemble the mid-fuselage. Three modules, which are simultaneously assembled prior to mating, make up the mid-fuselage structure. This modular approach provides greater efficiency and access to the densely packed mid fuselage structure.

A unique tooling process assembles each module vertically, which helps fit parts in the high tolerance locations of the mid fuselage. An elevator that runs in the air inlet ducts provides access within the structure. The modules are then switched to the horizontal position for mating. The initial vertical assembly provides optimum manpower to the module, decreasing the overall assembly span time, which translates into significant dollar savings.

Like the entire aircraft, the F-22 mid-fuselage was developed in an Integrated Product Team (IPT) environment. Members of the teams include personnel from various disciplines. The process has worked extremely well for the program, resulting in a significant decrease in engineering changes and scrapped parts.

The composition of the F-22 airframe uses a unique combination of materials to provide the best cost and weight balance. Unlike conventional aircraft, only 35% of the F-22 mid fuselage structure is aluminum. Composites make up 23.5% and titanium is nearly 35%. One of the four one-piece titanium bulkheads is the largest single piece of titanium ever to be used on an aircraft.

This optimum mixture was the result of extensive material trade studies that evaluated cost and weight benefits of various design, material and manufacturing concepts. A critical part of these studies was an extensive analysis of thermal expansions that can induce significant stresses into the airframe This study reduced the risk that is normally associated with use of multiple materials in airframe design.

Because of its width, the mid fuselage has to sit at almost a 45-degree angle in its reusable metal shipping container. This is so its shipping box will fit on a flatbed truck and still be allowed on roads from Texas to Georgia.

Aft Fuselage

Boeing began major assembly of the aft fuselage for the world's first F-22 in June 1996 at its Developmental Center in Seattle, Wash. Boeing began the process by loading the left-hand forward boom, a large component that contains fuel and carries structural loads, into the aft fuselage assembly fixture.

The F-22 aft fuselage houses the two Pratt & Whitney-built F119 engines that power the F-22. It also contains all or part of the aircraft's environmental control system and fuel, electrical, hydraulic, and engine subsystems. The aft fuselage is designed to withstand supersonic speeds for extended periods of time and extremely 'high-g' maneuvers.

The aft fuselage is 67 percent titanium, 22 percent aluminum and 11 percent composite by weight. A completed aft fuselage weighs 5,000 pounds and measures 19 feet long by 12 feet wide.

Approximately 25 percent (by weight) of the aft fuselage is comprised of large electron beam welded titanium forward and aft booms. The largest of these booms, the forward boom, is more than 10 feet long and weighs approximately 650 pounds The welded booms of the aft fuselage are extremely weight-efficient and reduce the use of traditional fasteners by approximately 75 percent.

The aft fuselage is shipped to Marietta in a reusable metal container that fits upright in a rail car, or can be placed on its side for shipping by cargo aircraft. The first aft fuselage was delivered to Marietta aboard a Lockheed-built C-5 Galaxy.

Wings

Boeing began assembly of the left-hand wing for the first F-22 in January 1996 when machinists loaded wing attachment parts for external fuel tanks and weapons pylons into an assembly tool.

By weight, the Boeing-built portion of the wing is 42 percent titanium, 35 percent composite, and 23 percent aluminum, steel, and other materials in the form of fasteners, clips, and other miscellaneous parts. Each wing weighs approximately 2,000 pounds.

Each of the wings measures 16 feet (side-of-body) by 18 feet (leading edge) and is roughly triangular in shape. The wings together give the F-22's planform a modified delta shape. The wings are designed to cruise at supersonic speeds for extended periods of time and withstand extremely 'high-g' maneuvers.

The wings incorporate structural design modifications made early in the development program. After analyzing the results of live-fire tests simulating severe combat damage, engineers chose to reinforce the wing by replacing every fourth composite spar with one made of titanium. The titanium reinforcements ensure that the F-22 will be more survivable in combat. The wings are designed to be interchangeable from airplane to airplane.

Principal suppliers to Boeing on the wing include Dow-United Technologies of Wallingford, Conn. (composite sine wave spars); Howmet of Norfolk, Va. (side-of-body rib and aileron support castings); Schlosser of Redmond, Ore. (pylon rib castings) and Curtiss Wright of Fairfield, N. J. (leading edge flap drive system).

The wing shipping containers are designed to transported either by rail (the preferred method) or by transport aircraft. The wings for the first F-22 were shipped to Marietta via Air Force transport aircraft.

SPECIALIZED MANUFACTURING AND

FINAL ASSEMBLY FACILITIES


Precision Drilling Center

The F-22 factory at Boeing introduces the use of an automated, laser-guided machine for drilling holes in components where fasteners are still required.

Originally developed for the B-2 bomber program, the system uses a laser tracker with a targeting feature and automated data feedback software to guide the drill to exactly the correct location before drilling, It does so by measuring the relative position of the drill to the structure and automatically making positional adjustments.

Operated by machinists, the system drills nearly 2,500 holes into the aft fuselage structure. The location, size, and depth of the holes are controlled by engineering data fed into a computer. The holes are used for attaching the upper composite skins and lower engine-bay doors to the aft fuselage structure.

Precision drilling is also being used to drill 14,000 holes in each F-22 wing set as well, which allows for attachment of the composite wing skins to the titanium and composite substructure.

Final Assembly


Final assembly operations for the new fighter will take place in the 3.5-million-square-foot B-1 building (which has been in near-continuous use since 1943) at Lockheed Martin Aeronautics Company in Marietta. However, other things necessary for the F-22 specifically - such as composite parts fabrication, painting, radar cross section verification, ground-based engine runs, and flight operations - take place in nearly $31.5 million worth of facility improvements that have been completed or will soon be finished. Most of the facilities improvements are located near the company's flight line.

Radar Cross Section (RCS) Verification Facility

The largest of the new buildings is the radar cross section (RCS) verification building. This 50,000 square-foot fully enclosed structure will be used to test the 'stealthiness' of each F-22 when it comes off the assembly line.

The main section of this building feature a 45-foot-diameter turntable with precise positioning capability that will allow for testing of full-size aircraft. This section of the building will measure 150 x 210 feet and will be 45 feet high. The facility will have a separate 60 x 210 foot anechoic chamber for aircraft antenna testing.

Burns & McDonald Engineers of Kansas City, Mo., designed the structure. It is expected to be operational by late summer 1997.

Robotic Coatings Facility

The other new building in Marietta to support the F-22 is the robotic coatings facility. This 43,000 square foot facility, which is fully compliant with all environmental regulations, will have separate areas for materials handling, subassembly painting, and a large bay where most of the exterior of the aircraft will be painted.

Two robotic painting systems will be used in the building, which will be designated as L-64 ('L' indicates a Lockheed Martin-owned building, '-64' is the next available number). The subassembly painting area will utilize a small, six-axis spray-head robot mounted on a 25-foot long track. This robot will be used to paint parts such as panels, doors, and the F-22's control surfaces before those parts are installed on the aircraft.

The aircraft's exterior will be painted with a standard six-axis spray head mounted on a hydraulically-operated arm that can be raised and lowered and is, itself, attached to a movable platform. This wire-guided platform, called an Automated Guided Vehicle (AGV), features electric drive wheels and hydraulic stabilizing jacks and will be positioned at several points around the aircraft as it is being painted.

The large robot has 28-foot horizontal reach and the spray head can be raised as high as 26 feet. The large robot, developed by Pratt & Whitney Waterjet, Inc., is an offshoot of the Large Aircraft Robotic Paint Stripping (LARPS) system developed under the Air Force's Manufacturing Technology (MANTECH) program for the Oklahoma City Air Logistics Center at Tinker AFB, Okla.

The robot's software will be verified on a full-scale mockup of the F-22 called the Finish Application Mockup (FAM), rather than risk an aircraft. The highly realistic FAM includes panel lines and sits at exactly the same height as the real aircraft. Once the paint robot's software is proven, the FAM will be used to test the systems in the RCS Verification Building.

The large robot allows for precise application of the aircraft's paint. Unlike many other aircraft, where a base coat is applied over the entire aircraft, and then the camouflage coat is added on top of that, the F-22's two-tone camouflage scheme of dark gray on a light gray will actually be applied separately.

The robot first paints the light gray surrounding what will be a camouflage area, but leaves a hole where the dark gray will go. It then goes back and adds the dark gray. This saves paint, and more importantly, doesn't add additional weight anywhere on the aircraft.

L-64 will measure 90 x 100 feet and will cost approximately $16.5 million (including the robots). Choate Construction of Atlanta was the prime contractor and operations began in the building in late 1996. As the F-22 manufacturing program expands, there are plans for a second painting facility to be built adjacent to the first.

Hush House

A third new facility on the Lockheed Martin flight line isn't actually new at all. The engine noise attenuation facility (more commonly known as a 'hush house') is being used for ground-run tests of each F-22's twin Pratt & Whitney F119-PW-100 engines was formerly located at McConnell AFB, Kan.

The facility, designated B-22 (the 'B' indicates a government-owned building) was disassembled, trucked to Marietta, and reassembled across the ramp from both of the other new buildings. Vita-Link was the prime contractor for the move, and Burns & McDonald provided engineering support.

Other Facilities

One feature unique to high-performance aircraft is ejection seats. In order to safely store and handle the pyrotechnics necessary for the F-22's ACES II ejection seats, the existing B-66 building will be modified. This small building, which was formerly used to monitor C-5 ground engine runs, is of sturdy construction (thick walls, etc.) and will contain an explosion should one occur.

The final major facility upgrade on the flight line is improvements to the existing L-10 building. This building houses flight test (and later production flight) operations for the F-22. The building will have the necessary utilities to support four aircraft at the same time. Pratt & Whitney will also have an engine buildup and repair area. Control room and locker area space will also be included.

The facility improvements for F-22 also took place in several other buildings of the Air Force-owned, Lockheed Martin-run plant. Office and Integrated Product Team support spaces for F-22 manufacturing personnel were constructed in the main B-1 building near the F-22 assembly line in 1995. This project was one of the first undertaken.

Another project completed in 1995 was activation of the composite parts fabrication area in the existing L-11 building, which was once used for assembly of JetStar executive transports.

The final major facilities improvement at Lockheed Martin Aeronautics Company was the renovation of the B-4 building, which is located near the B-1 main assembly building. Two non-flyable F-22 airframes (the static and fatigue test articles) will undergo ground testing in one high bay of this building, and, in order to accomplish those tests, a new hydraulic system was installed.


Now lets review weapons systems-

For its primary air-to-air role, the F-22 will carry six AIM-120C and two AIM-9 missiles. For its air-to-ground role, the F-22 can internally carry two 1,000 pound-class Joint Direct Attack Munitions (JDAM), two AIM-120C, and two AIM-9 missiles. With the Global Positioning System-guided JDAM, the F-22 will have an adverse weather capability to supplement the F-117 (and later the Joint Strike Fighter) for air-to-ground missions after achieving air dominance.

The weapons bay played a huge role in the design evolution of the F-22. The aircraft is essentially wrapped around its internal bay, which is an essential characteristic of the F-22's stealthy design. The limited space drove the configuration of the launchers and acoustic suppression devices. Launching weapons from an internal bay is not a new problem. The F-111 and F-117 have internal bays as well as older aircraft like the F-102, F-105, and F-106. Historically, bay acoustics and weapon re-contact with structure during separation have been issues. The F-22 has a requirement to launch weapons throughout the service envelope at roll rates up to 100 degrees per second. This is a groundbreaking requirement made even tougher by tight clearances and flow fields that result from internal carriage.

The F-22 carries its primary armament, the AIM-120C Advanced Medium-Range Air-to-Air Missile (AMRAAM) internally on the EDO Corp.-built LAU-142/A pneudraulic (pneumatic and hydraulic) launcher, called the AMRAAM Vertical Eject Launcher (AVEL). Six launchers mounted in the main weapon bays carry and launch the AMRAAMs. The AVEL is very stiff in order to control missile movement in the weapons bay and supply the proper ejection forces on the missile. The AVEL, which is made mostly of aluminum, has a nine-inch stroke, and ejects the missile out of the bay at more than 25 feet per second, with a force of 40Gs. The long stroke and high velocity are required to safely separate the missile from the aircraft in all combat conditions. Unlike conventional missile launchers, the AVEL requires no explosive pyrotechnics cartridges, (which means the AVEL requires less logistics support and maintenance) but instead uses the aircraft's hydraulic system to eject the missile. The entire missile launch sequence --door opening, AVEL ejecting the missile, missile ignition and flyout, door closing --takes just seconds.

The F-22's combat configuration is "clean", that is, with all armament carried internally and with no external stores. This is an important factor in the F-22's stealth characteristics, and it improves the fighter's aerodynamics by dramatically reducing drag, which, in turn, improves the F-22's range. The F-22 has four under wing hardpoints, each capable of carrying 5,000 pounds. A single pylon design, which features forward and aft sway braces, an aft pivot, electrical connections, and fuel and air connections, is used. Either a 600-gallon fuel tank or two LAU-128/A missile launchers can be attached to the bottom of the pylon, depending on the mission.

There are two basic external configurations for the F-22:

Four 600 gallon fuel tanks, no external weapons: This configuration is used when the aircraft is being ferried and extra range is needed. A BRU-47/A rack is used on each pylon to hold the external tanks.
Two 600 gallon fuel tanks, four missiles: This configuration is used after air dominance in a battle area has been secured, and extra loiter time and firepower is required for Combat Air Patrol (CAP). The external fuel tanks, held by a BRU-47/A rack are carried on the inboard stations, while a pylon fitted with two LAU-128/A rail launchers is fitted to each of the outboard stations.
An all-missile external loadout (two missiles on each of the stations) is possible and would not be difficult technically to integrate, but the Air Force has not stated a requirement for this configuration.

End-to-end weapons integration missile shots have had mixed results in testing, according to DOT&E. Four shots have demonstrated the capability to engage and destroy enemy aircraft in specific, discreet combat representative scenarios. However, three other shots indicated fire control deficiencies exist that need to be resolved in development. Some F/A-22 weapons separation, fully integrated guided missile test launches, and JDAM testing are planned to be done concurrently with IOT&E. JDAM employment is planned for follow-on test and evaluation, to be conducted after IOT&E. DOT&E believes that a large F/A-22 development risk, from both a technical and schedule perspective, lies in the integration of the avionics suite with realistic air-to-air and, eventually, air-to-surface weapons employment.

AIM-120 Advanced Medium-Range Air-to-Air Missile (AMRAAM)
The F-22's primary weapon is the AIM-120 Advanced Medium-Range Air-to-Air Missile (AMRAAM). This missile is a replacement for the AIM-7 Sparrow, which was developed in the 1950s, and was still in front-line service into the early 1990s. The AIM-120 was developed to provide an all-weather, all-launch environment capability for the F-22, as well as the Air Force's in-service F-15 Eagle and F-16 Fighting Falcon, and the Navy's F-14 Tomcat and F/A-18 Hornet.

The AIM-120 (which has no official nickname, but is called "Slammer" by pilots) is carried internally in the F-22's main weapons bay that is located on the underside of the fighter tucked under the inlets. The main bay is covered by two thermoset composite bifold doors that open outward. When the F-22 is in first-day-of-a-war combat configuration, all missiles are carried in the main weapons bay only. The typical combat load is six AIM-120C. Three in each side of the main weapons bay with the center missile staggered ahead of the inboard and outboard missiles. The F-22 can carry four of the older, longer-finned AIM-120A if necessary.

Each missile is carried on an EDO Corp.-built LAU-142/A pneudraulic (pneumatic and hydraulic) launcher, called an AMRAAM Vertical Eject Launcher (AVEL). The AVEL is substantial (nearly 113 pounds each) in order to minimize missile movement in the weapons bay. The AVEL, which is made mostly of aluminum, has a nine-inch stroke, and ejects the missile out of the bay at more than 25 feet per second with a force of 40 G (40 times the force of gravity) at peak acceleration. Unlike conventional missile launchers on other aircraft, the AVEL requires no pyrotechnics, and it requires less logistics support than other launchers.

The missiles are loaded from the opposite side of the aircraft AIM-120 Loading in Main Weapons Bay (missiles in the left side of the weapons bay are loaded from the right and visa versa), in order to clear the open main weapons bay doors. The current MJ-1 load vehicle (called a jammer) is used to load the missiles into the F-22. The missiles are staggered in the bay so fins on adjacent missiles do not interfere with each other when they are launched.

The missile gets target information from the aircraft prior to launch via a Military Standard (Mil Std) 1760 data bus. Once launched, the missile can operate independent of the launch aircraft, as it has its own inertial guidance system and an active radar, allowing the F-22 pilot to launch the missile and leave the area, thus avoiding a close-in dogfight. However, if necessary, the missile can also receive mid-course target updates from the launch aircraft. The entire launch sequence (door opening, AVEL ejecting the missile, missile ignition and flyout, door closing) takes just seconds. The combination of the aircraft's stealth characteristics, its integrated avionics, and the AIM-120 missile gives the F-22 a "first-look, first-shot, first-kill" capability.

AIM-9M Sidewinder
The F-22's short-range missile armament is the AIM-9M Sidewinder. This missile has been continuously updated since its forerunner (then designated N-7) destroyed a radio-controlled drone in a test at China Lake, Calif., in September 1953. Developed essentially from spare parts by the Naval Ordnance Test Center, Sidewinder entered service with the Air Force in 1956. Today, the AIM-9 is used on nearly every U. S. Air Force and Navy fighter (including F-15, F-16, A-10, F-14, and F/A-18) and those of many allied nations. It can even be fired from several types of military helicopters. Well over 150,000 Sidewinders have been built.

The AIM-9M is currently the only operational Air Force variant. This model has all-aspect (any direction) intercept capability. It also has improved defenses against infrared countermeasures, enhanced background discrimination capability, and a reduced-smoke rocket motor. These upgrades increase the missile's ability to locate and lock-on a target and decrease the missile's chances for detection. Deliveries to the Air Force began in 1983. A new variant, AIM-9X, is now in development. This missile will retain many of the Sidewinder's capabilities while strengthening the design with airframe improvements and advanced seeker technology, including staring focal plane arrays, adaptive compensation techniques, and infrared signals processing.

On the F-22, one AIM-9 is carried in each of the aircraft's side weapons bays, which are located on the outside of the engine inlets. There are no plans to carry the AIM-9 in the F-22's main weapons bay. The side bays are each covered by two thermoset composite doors that run the length of the compartment and are hinged at the top and bottom of the bay. Although AIM-9X is slightly longer than the AIM-9M, it will still fit in the F-22 without modification to the side weapons bays.

The missiles are carried on a Lockheed Martin Tactical Aircraft Systems-built LAU-141/A hydraulic launcher, called a Trapeze Launcher. This launcher, which uses some components from the existing LAU-128/A launcher, is basically the wingtip launch rail from an F-16 with a swing out mechanism that extends rapidly. The LAU-141/A is also fitted with a missile motor plume deflector, which prevents damage to the side weapons bay as the missile launches off the rail. Each missile is loaded by opening the doors, extending the rail, sliding it on the rail, retracting the missile, and closing the doors. Nearly all Sidewinders are loaded manually, using a three-person load crew. AIM-9 loading for F-22 will be no different.

As the AIM-9 uses infrared guidance, the missile first has to acquire the target. To launch a Sidewinder from the F-22, the side weapons bay doors open; the Trapeze Launcher, with missile attached, extends to put the missile's seeker into the slipstream; the seeker acquires the target; the missile ignites and flies off the rail. The Trapeze Launcher then retracts, and the weapons bay doors close. Once launched, the F-22 pilot can leave the fight, as Sidewinder is autonomous, following its seeker to the target, after it leaves the launch rail. The entire Sidewinder launch sequence, from door opening to door closing, takes just seconds.

GBU-32 JDAM Joint Direct Attack Munition
JDAM is a tail guidance kit that converts existing unguided free-fall bombs into near precision-guided "smart" munitions. It also includes strap-on strakes that attach to the bomb's body for stability. Adding a new tail section containing an Inertial Navigation System (INS)/Global Positioning System (GPS) guidance control unit to existing inventories of Mk. 83 1,000-pound-class general purpose conventional bombs gives the F-22 a highly accurate, autonomous, high altitude all-weather conventional bombing capability. Currently, the JDAM tail guidance kit gives existing "iron bombs" a circular error probable (CEP, the measure of weapons accuracy) of under 15 meters, but a planned improvement program will give the weapon a CEP of considerably less than 10 meters. JDAM is intended for use on a variety of Air Force and Navy aircraft including B-1, B-2. B-52, F-15E, F-16, F-117, and F/A-18.

The F-22 can only carry the 1,000-pound class JDAM weapon. For the F-22, the JDAM tail guidance kit fits on the Mk. 83 1,000-pound-class conventional bomb. Weight of the Mk. 83 bomb and tail guidance kit is approximately 1,015 pounds The combination of the stealthy F-22 and the precision capability of the GBU-32 allows the F-22 pilot to drop the weapon from altitudes of approximately 40,000 feet to a range of approximately 15 miles.

The GBU-32 is only carried in the F-22's main weapons bay. A typical combat load consists of two GBU-32. One GBU-32 is carried inboard in each side of the main weapons bay. When loaded with GBU-32, there is still sufficient room in the F-22's main weapons bay to carry two AIM-120C air-to-air missiles (one in each side of the bay, in addition to the two AIM-9 Sidewinders in the side weapons bays), which means that even on a mission to attack ground targets, the F-22 retains significant air-to-air combat capability.

Each 1,000-pound-class GBU-32 will be loaded from the opposite side of the F-22 (the JDAM in the left side of the weapons bay is loaded from the right and visa versa), in order to clear the open main weapons bay doors. The current MJ-1 load vehicle (called a jammer) is used to load the GBU-32 into the F-22. The GBU-32 is carried on the Air Force's standard BRU-46/A bomb rack (which is built by EDO). The weapon is carried on the inboard side of the bay with an adjacent AIM-120C missile staggered on the outboard side. This is so tail fins on the bomb and the missile's wings do not interfere with each other when the weapons are either released or launched.

The GBU-32 gets target information from the aircraft prior to release via a Miltary Standard (Mil Std) 1760 data bus. JDAM can be dropped by an aircraft from up to 15 miles from the target. In addition to its own inertial guidance system, the weapon receives in-flight position updates from the 24-satellite GPS satellite constellation which help guide the bomb to the target. The GPS constellation provides 24-hour navigation information to military and civilian users. The GBU-32's autonomous operation allows the carrying aircraft to release the weapon and leave the area, thus avoiding an enemy's integrated air defense (surface-to-air missiles, antiaircraft artillery ("triple A"), and radars) system, but still delivering the weapon to the target.

M61A2 20-mm Cannon
The F-22's close-range weapon is the M61A2 20mm cannon and its associated components. The M61 is a proven gun, having been the U. S. military's close-in weapon of choice dating back to the 1950s. The F-104, F-105, later models of the F-106, F-111, F-4, B-58, all used the M61, as does the Air Force's current F-15 Eagle and F-16 Fighting Falcon, and the Navy's F-14 Tomcat and F/A-18 Hornet. The system is integrally mounted in the aircraft and located on the right side of the aircraft between the wing (top side) and fuselage. It is a fixed-forward firing mount. A gun door, located in the wing root area, is hydraulically controlled to open when firing the gun, which allows the rounds and blast pressure to clear the muzzle. A 480-round closed loop ammunition feed and storage subsystem is housed integrally under the right wing root/fuselage for easy ammo upload and download of empty casings. The gun system consists of the M61A2 gun, the Linear Linkless Ammunition Handling System (LLAHS), the hydraulic drive system, and the gun door/gun port and gas purge system.

The M61A2 is a lightweight version of the M61A1. Most of the weight savings was achieved by machining down the barrel thickness. The M61A2 is Government Furnished Equipment (GFE), that is, purchased by the government under separate contract and provided to the F-22 contractor team. Power to operate the gun is provided by hydraulic pressure supplied by the aircraft's hydraulic system. Each of the gun's six barrels fires only once during each revolution of the barrel cluster. The six rotating barrels contribute to long weapon life by minimizing barrel erosion and heat generation. The gun's rate of fire, essentially 100 rounds per second, gives the pilot a shot density that will enable a "kill". With 480 rounds, the pilot has roughly five shots with the gun.

The inherent capabilities of the F-22 (stealth, advanced avionics, supercruise) and advanced air-to-air missiles such as AIM-120 AMRAAM and AIM-9 Sidewinder, will likely render use of the gun unnecessary in combat. However, as history has demonstrated (most glaringly with the F-4 in Vietnam), at some point, the air battle comes down to a dogfight, and the M61A2, along with the F-22's superior maneuverability, gives the pilot one more option.

The General Dynamics Armament System-developed Linear Linkless Ammunition Handling System (LLAHS) consists of a 480 round ammunition storage container with drive train and integral access (reload) unit, an ammunition conveyor assembly, a hydraulic drive unit, a rounds limiter, and a last round switch. There are no links between rounds (hence the term "linkless") an innovation that eliminates completely any potential jamming of the gun breech. Ammunition is transported from the container to the gun breech by a direct extension of the carrier chain, which also carries the empty cartridges back to the ammunition storage container to form a closed loop system. The LLAHS is loaded manually from the ground. The rounds limiter is an electromechanical device that is preset to limit the number of rounds that can be fired on a training flight. The last round switch shuts down the gun when it senses the empty casing of the first round fired. The LLAHS is located very near to the aircraft's center of gravity, so by retaining the casings, even after all the rounds are fired, there is no change forward or aft to the aircraft's center of gravity. Also, by not ejecting the casings, a potentially serious foreign object debris (FOD) problem (i.e. ingesting casings into the engines) simply does not exist.

The gun hydraulic drive unit is a 42 horsepower fixed displacement motor sized to achieve a 6,000 round per minute gun firing rate at all flight loading conditions. The gun port door is mechanized such that is opened to provide an exit path out of the aircraft for the projectiles. It is activated when the pilot squeezes the trigger on the control stick (the first detent) in the cockpit. The door opens to 90 degrees and is activated in milliseconds. When the trigger is released by the pilot (or the last round switch engaged), the door is commanded to close. It takes several seconds for the door to close completely. The door is an aid to the F-22's stealth characteristics, and it helps the aircraft's aerodynamics by reducing drag. The gun port is a steel casting that is located under the port door. It is used to protect the aircraft and its structure from gun muzzle blast by deflecting projectiles up and away from the aircraft surface. If a misfire occurs in the one-half portion of the gun port, it is designed to capture the projectile.

The gun gas purge system consists of an actuated purge door that opens at the same time as the gun port door. The purge door, located on the fuselage side near the gun breech, forces outside air (ram air) into the aircraft when opened and a static screened vent (on the top of the fuselage) allows gun gas (which is mostly hydrogen, and as such, explosive) and ram air to exit overboard. When the trigger is released by the pilot (or the last round switch is engaged), the door is commanded to close M61A2 20-mm Gun System for F-22.

F-22 Carriage Capability
The F-22's combat configuration is "clean", that is, with all armament carried internally and with no external stores. This is an important factor in the F-22's stealth characteristics, and it improves the fighter's aerodynamics by dramatically reducing drag, which, in turn, improves the F-22's range. The F-22 has four under wing hardpoints, each capable of carrying 5,000 pounds. A single pylon design, which features forward and aft sway braces, an aft pivot, electrical connections, and fuel and air connections, is used. Either a 600-gallon fuel tank or two LAU-128/A missile launchers can be attached to the bottom of the pylon, depending on the mission.

There are two basic external configurations for the F-22: Four 600 gallon fuel tanks, no external weapons: This configuration is used when the aircraft is being ferried and extra range is needed. A BRU-47/A rack is used on each pylon to hold the external tanks. Two 600 gallon fuel tanks, four missiles: This configuration is used after air dominance in a battle area has been secured, and extra loiter time and firepower is required for Combat Air Patrol (CAP). The external fuel tanks, held by a BRU-47/A rack are carried on the inboard stations, while a pylon fitted with two LAU-128/A rail launchers is fitted to each of the outboard stations. An all-missile external loadout (two missiles on each of the stations) is possible and would not be difficult technically to integrate, but the Air Force has not stated a requirement for this configuration.

The LAU-128/A rail launcher is the standard rail launcher used today on the F-15 and can carry either of the missiles used on the F-22, AIM-120 AMRAAM or AIM-9 Sidewinder. However, both missiles carried on the fire missile adapter configuration for F-22 must be the same type for aircraft weight and balance considerations. The 600-gallon fuel tanks are similar to the same external tanks that are used on the current F-15 Eagle. However, a new tank is being developed that has baffles in it to prevent the fuel from sloshing. This gives the tank better center of gravity control, which allows for safe jettisoning of the tanks. The BRU-47/A rack is not the same type of rack that is used internally on the F-22 to carry the GBU-32 1,000-pound class Joint Direct Attack Munition (JDAM), although they are similar and both are currently in use. However, there are no plans to carry JDAM externally on F-22. The BRU-47 will only be used to hold the external fuel tanks.

The pylon itself is designed for minimal impact on aircraft performance. If it becomes necessary for the pilot to jettison the external stores, the entire pylon is jettisoned along with the tank or missile launch rails. The pylon has an aft pivot, so when the stores are jettisoned, the forward attach point is released first, the pylon rotates on the pivot, and then the aft pivot is released. This motion allows the pylon, along with the tank or launch rail to clear the aircraft when it is released into the slipstream.

Defcon 6

Now lets review the F-22 Avionics-


Avionics share as large a part in the success of a fighter as the ability to maneuver and fly fast, or to "turn and burn." The design issues that had to be addressed involved solving the technical and organizational challenges of running the program. Also crucial to the design, was the reduction of pilots' "housekeeping" responsibilities.

The F-22 will have the first integrated avionics suite ever flown on a combat aircraft. The Northrop/Grumman-Texas Instruments APG-77 radar, Lockheed Martin electronic warfare suite and the TRW communications/navigation/IFF subsystems are all included.

The requirements for the F-22's avionics system are derived from the F-22 Weapon System Concept, the guiding design principles for the overall weapons system. The integrated avionics system is one of the key elements (the others being stealth, maneuverability, and supercruise) that will give the F-22 the tactical advantage against the threats of the future.

The avionics system requirements are based on zones of operational interest. These zones, based on enemy and own ship capabilities, determine the information requirements for each object encountered in the mission. Today's fighters have some of the same sensing capabilities and subsystems to be controlled, but their federated architecture (that is, each avionics function has its own processor and essentially works independently) makes the pilot the integrator of data and the manager of all the supporting subsystems.

The F-22 operational concept, and the sophistication of the various systems requires integration at many levels, including sensor control, sensor data fusion, the architectural components that support these functions, and the displays that are the primary means of communication with the pilot. The key attributes of the avionics system are driven by the other weapon system characteristics such as stealth, supercruise, reliability, availability, and need for growth capacity.

Integrated avionics means different things to different people.

To the pilot, it means all the information is coordinated and available from a single source.
To the software engineer, it means access to shared data about the situation, the mission, and the aircraft systems.
To the hardware designer, it means common modules in a single backplane with the connectivity and bandwidth to support the required processing.
Coherent presentation and control (the pilot's view of integration) is not simply a way of organizing functions or routing lots of data to a single display. It actually includes additional functionality, such as situation assessment and weapons fire control. The software view of integration means that the various functional pieces of the software must have efficient access to globally coherent information, such as track files, navigation data, mission data, and aircraft system status information. A hardware architecture built on common components, common modules, standard buses, and common operating system provides the infrastructure for the processing and communication between the processes described above. In addition, modular approach allows for easy expansion of capacity and capability, fault tolerance, and reconfiguration.

Translating the system requirements into a producible, affordable, and maintainable design was the work of the Engineering and Manufacturing Development (EMD) program. The basic concept, derived from the Pave Pillar program in the 1980s (which included development of Integrated Communications, Navigation, Identification Avionics (ICNIA) and Integrated Electronic Warfare System (INEWS) systems) was to provide all the signal and data processing resources in a central collection of modular processors, linked to the sensors, subsystems, and pilot by high-speed data busses. The F-22 architecture provides just such a system, interfaced to the air-cooled, flight safety critical systems such as the flight control system.

The TRW Communications/Navigation/Identification (CNI) system includes an intra-flight datalink, JTIDS Joint Tactical Information Distribution System link, and an Identification Friend or Foe (IFF) system. Boeing is responsible for mission software and avionics integration. The aircraft has a Litton LTN-100G laser gyroscope inertial reference, a global positioning system and a microwave landing system.

The F-22's avionics suite features extensive use of very high-speed integrated circuit (VHSIC) technology, common modules, and high-speed data buses. The avionics suite is a highly integrated system maximizing performance allowing the pilot to concentrate on the mission, rather than on managing the sensors as in current fighters. Technologies incorporated in the F-22 include a Common Integrated Processor (CIP), a central "brain" with the equivalent computing throughput of two Cray supercomputers; shared low-observable antennas; ADA software; expert systems; advanced data fusion-cockpit displays; integrated electronic warfare system (INEWS) technology; integrated communications, navigation, and identification (CNI) avionics technology; and fiber optics data transmission. Nearly all of these elements were demonstrated during dem/val in a prototype architecture.

Common Integrated Processor (CIP)

The Hughes-built Common Integrated Processor (CIP) serve as the "brains" for the F-22's totally integrated avionics system. CIPs are the central, networked computers that enable the integration of radar, electronic warfare, and identification sensor data, as well as communication, navigation, weapon, and systems status data into coherent, fused information for communication to the pilot via multi-function displays. Rather than radar, the electronic warfare system, and the electronic warfare system having individual processors, the CIP supports all signal and data processing for all sensors and mission avionics.

The CIP modules have the ability to emulate any of the electronic functions through automatic reprogramming. For example, if the CIP module that is acting as radio dies, one of the other modules will automatically reload the radio program and take over the radio function. This approach to avionics makes the equipment extremely tolerant to combat damage as well as flexible from a design upgrade point of view.

There are two CIPs in each F-22, with 66 module slots per CIP. The CIPs (which is quite literally the size of a oversized bread box) are liquid cooled avionics racks containing both signal processing and data processing modules inserted into common backplane. They have identical backplanes, and all of the F-22's processing requirements can be handled by only seven different types of processors. There are 33 signal processors and 43 data processors interconnected via a fault-tolerant network. Each processing element is manufactured and packaged as an approximately 6x7x3/8ths inch line replaceable module (LRM) for ease of flightline maintenance.

Each module is limited by design to only 75 percent of its capability, so the F-22 has 30 percent growth capability with no change to the existing equipment. Currently, 19 of 66 slots in CIP 1 and 22 of 66 slots in CIP 2 are not populated and are available for growth. There is space, power and cooling provisions in the aircraft for a third CIP, so the requirement for a 200 percent avionics growth capability in the F-22 can be easily met. There is coordinated plan for technology growth that will help keep the CIP at state-of-the-art levels. As electronics continue to get smaller and more powerful, it is conceivable that there could be 300 percent increase in avionics capability.

The exponential explosion of computer technology in recent years has allowed the F-22 team to radically alter every aspect of the program from detailed design through manufacturing, communication, and into the cockpit itself. An example of the effect of the advances in computer technology is a comparison between the computers used in the Lunar Module and those used in the F-22. The Lunar Module's computers operated at 100,000 operations per second and had 37 kilobytes of memory. Today, the F-22's Common Integrated Processor main mission computers operate at 10.5 billion instructions per second and have 300 megabytes of memory. These numbers represent 100,000 times the computing speed and 8,000 times the memory of the Apollo moon lander.

AN/APG-77 Radar

The AN/APG-77 radar is the F-22's primary sensor and is a long-range, rapid-scan, and multi-functional system. A Northrop Grumman-led joint venture with Raytheon is developing the active-element electronically scanned array radar. Northrop Grumman is also responsible for the radar sensor design, software, and systems integration.

The AN/APG-77 radar is an active-element, electronically scanned (that is, it does not move) array that features a separate transmitter and receiver for each of the antenna's several thousand, finger-sized radiating elements. Most of the mechanical parts common to other radars have been eliminated, thus making the radar more reliable. This type of antenna, which is integrated both physically and electromagnetically with the airframe, provides the frequency agility, low radar cross-section, and wide bandwidth necessary to support the F-22's air dominance mission. The radar is key to the F-22's integrated avionics and sensor capabilities. It will provide pilots with detailed information about multiple threats before the adversary's radar ever detects the F-22.

The AN/APG-77 radar a novel type of electronically scanned phased array. In what is likely to be the most advanced airborne radar in the world, individual transmit and receive modules are located behind each element of the radar array. The transmit function of the solid-state microwave modules supplants the traveling wave tubes used in prior radars like the APQ-164. The active, electronically scanned array (ESA) configuration has a wider transmit bandwidth while requiring significantly less volume and prime power. The system represents about half the weight of an equivalent passive ESA design. Each of the hundreds of individual solid-state devices generates only small amounts of power, but the aggregate for the entire array is substantial.

The F-22 s APG-77 electronically scanned array antenna is composed of several thousand transmit/receive modules, circulators, radiators and manifolds assembled into subarrays and then integrated into a complete array. The baseline design used thousands of hand-soldered flex circuit interconnects to make the numerous radio frequency, digital, and direct current connections between the components and manifolds that make up the subarray. Northrop Grumman Corporation, of Baltimore, MD, has developed an improved manufacturing process for F-22 aircraft radar components. The new process could result in a cost avoidance of nearly $87 million on the planned production run for the aircraft. By replacing the hand-soldered flex circuit interconnects with automated ribbon bond interconnects, the first pass yield of the subarray assembly has been vastly improved.

The AN/APG-77 radar antenna is a elliptical, active electronically scanned antenna array of 2000 transmitter/receive modules which provides agility, low radar cross section and wide bandwidth. The radar is able to sweep 120 degrees of airspace instantaneously. In comparison to the F-15 Strike Eagle's APG-70 radar takes 14 seconds to scan that amount of airspace. The APG-77 is capable of performing this feat by electronically forming multiple radar beams to rapidly search the airspace.

The system exhibits a very low radar cross section, supporting the F-22's stealthy design. Reliability of the all-solid-state system is expected to be substantially better than the already highly reliable F-16 radar, with MTBF predicted at more than 450 hours.

The APG-77 radar offers significant advantages over previous combat radars. Among its most attractive benefits is the integration of agile beam steering. This feature allows a single APG-77 radar to carry out multiple functions, such as searching, tracking, and engaging targets simultaneously. Agile beam steering also enables the radar to concurrently search multiple portions of airspace, while allowing continued tracking of priority targets.

The Low Probability of Intercept (LPI) capability of the radar defeats conventional RWR/ESM systems. The AN/APG-77 radar is capable of performing an active radar search on RWR/ESM equipped fighter aircraft without the target knowing he is being illuminated. Unlike conventional radars which emit high energy pulses in a narrow frequency band, the AN/APG-77 emits low energy pulses over a wide frequency band using a technique called spread spectrum transmission. When multiple echoes are returned, the radar's signal processor combines the signals. The amount of energy reflected back to the target is about the same as a conventional radar, but because each LPI pulse has considerably less amount of energy and may not fit normal modulation patterns, the target will have a difficult time detecting the F-22.

The F-22 and its APG-77 radar will also be able to employ better Non-Cooperative Target Recognition (NCTR). This is accomplished by forming fine beams and by generating a high resolution image of the target by using Inverse Synthetic Aperture radar (ISAR) processing. ISAR uses Doppler shifts caused by rotational changes in the targets position to create a 3D map of the target. The target provides the Doppler shift and not the aircraft illuminating the target. SAR is when the aircraft provides the Doppler shift. The pilot can compare the target with an actual picture radar image stored in the F-22's data base.

Communications/Navigation/Identification (CNI)

The F-22's Communications/Navigation/Identification (CNI) 'system' is a collection of communication, navigation, and identification functions, once again employing the CIP for signal and data processing resources. Each CNI function has its associated aperture installed throughout the aircraft.

Inter/Intra-Flight Data Link (IFDL)

Included in the Communications/Navigation/Identification (CNI) system is an Inter/Intra-Flight Data Link (IFDL) that allows all F-22s in a flight to share target and system data automatically and without radio calls. The Inter/Intra Flight Data Link is one of the powerful tools that make all F-22s more capable. One of the original objectives for the F-22 was to increase the percentage of fighter pilots who make 'kills'. With the IFDL, each pilot is free to operate more autonomously because, for example, the leader can tell at a glance what his wing man's fuel state is, his weapons remaining, and even the enemy aircraft has targeted. Targets can be automatically prioritized and set up in a shoot list with one button push. A 'shoot' cue in the head up display alerts the pilot to the selected weapon kill parameters and he fires the weapons. Both a pilot's and wing man's missile flight can be monitored on the cockpit displays. Classical tactics based on visual 'tally' (visual identification) and violent formation maneuvers that reduce the wing man to 'hanging on' may have to be rethought in light of such capabilities. This link also allows additional F-22 flights to be added to the net for multi-flight coordinated attack.

Electronic Warfare (EW)

The Electronic Warfare 'system' is also a collection of apertures, electronics, and processors (again using the CIP) that detect and locate signals from other aircraft and controls the F-22's expendable countermeasures (chaff and flares). The EW aperture locations provide all-aspect coverage, and the system includes a missile launch detection capability.

The F-22's electronic warfare system includes a radar warning receiver and a Lockheed Martin Sanders missile launch detector.

Stores Management System (SMS)

The Stores Management System (SMS) controls weapons launch sequences, including door control (for the internal weapons carriage) and emergency weapons jettison.

Power Supplies

Boeing manufactures the power supplies for most of the F-22's electronic systems. The power supply modules designed for the F-22's avionics are cooled with polyalphaolefin (PAO) liquid coolant to carry away heat generated by the supplies' power-conversion process. The reduced temperature allows the component's power output to increase from 250 watts to 400 watts. Each module measure 6.41 inches by 5.99 inches by 0.58 inches and weighs 1.8 pounds.

Liquid Flow-Through Cooling

The PAO cooling concept also applies to all types of Line-Replaceable Modules (LRMs) in the CIP. Liquid flow-through cooling improves reliability, lending to an mean time between failures (MTBF) of 25,000 hours. The coolant, which is routed through the module, comes from the F-22's environmental control system (ECS). The LRM concept is the baseline for all of the power supply modules built for the F-22 to minimize maintenance time. Built-in diagnostic routines will pinpoint a failed power supply on an F-22 and allow maintenance personnel to remove it, replace it and verify proper operation within 15 minutes.

Avionics Racks

The avionics racks, located in the forward fuselage, contain the processing, not only for the mission avionics, but also for the Vehicle Management System (VMS) and Integrated Vehicle System Controller (IVSC). The flight worthy racks, including the liquid-flowthrough racks required for the CIP, are now in production.

Inertial Reference System (IRS)

Two Litton LN-100F ring laser gyroscopes in the forward fuselage provide the aircraft a self-contained method of knowing where it is. These inertial measurement units, placed nose to nose behind the radar on the aircraft's centerline, are operated off separate data buses to provide independent measurement data. In normal flight, IRS data is fused with Global Positioning System (GPS) data to provide an extremely reliable navigational capability. The IMUs are the only completely reliable source of data for the aircraft at attitudes above 30 degrees angle of attack (AOA). One of the IRS units feeds data directly into the CIP for gun control steering.

Software

The software that provides the avionics system's full functionality is composed of approximately 1.7 million lines of code. Ninety percent of the software is written in Ada, the Department of Defense's common computer language. Exceptions to the Ada requirement are granted only for special processing or maintenance requirements. The software development plan, though stretched as a result of past funding constraints, has remained essentially unchanged since the start of Engineering and Manufacturing Development.

The avionics software is integrated in three blocks, each building on the capability of the previous block. Each block cycle is a sequence of subsystem deliveries, integration testing at the Avionics Integration Lab (AIL) at Boeing (see AIL in the Test Facilities section), and then delivery to Lockheed Martin in Marietta, Ga., for final integration into the aircraft and check out, as well as support to the aircraft.

Block 1 is primarily radar capability, but Block 1 does contain more than 50 percent of the avionics suite's full functionality source lines of code (SLOC) and provides end-to-end capability for the sensor-to-pilot data flow. The fourth EMD F-22 was the first to have a full avionics suite, and it flew in mid 1999.

Block 2 is the start of sensor fusion. It adds radio frequency coordination, reconfiguration, and some electronic warfare functions. Block 2 was integrated into the aircraft in late 1999.

Block 3 encompasses full sensor fusion built on enhanced electronic warfare and CNI functions. It has an embedded training capability and provides for electronic counter-counter measures (ECCM). It was integrated into the aircraft in the spring of 2000. Block 3.1, which adds full GBU-32 Joint Direct Attack Munition (JDAM) launch capability and Joint Tactical Information Distribution System (JTIDS) receive-only capability, was integrated in April 2000.

The proposed Block 4 software will be post-Engineering and Manufacturing Development. It is scheduled to be integrated on the Initial Operational Capability F-22s and will likely include helmet-mounted cueing, AIM-9X integration, and Joint Tactical Information Distribution System send capability.

CIP hardware was available well before the subsystem application software code and unit test phases began for the Block 1 software. For some of the higher risk software, such as sensor data fusion, specific algorithm testbeds have been constructed, and prototype software, which is instrumented to measure performance (correlation times, accuracy, etc.). has been operational since the start of EMD.

Flying Test Bed (FTB)

The Flying Test Bed (FTB) represents an interim test environment between the controlled, but static environment of the ground labs, and the dynamic flight testing of the F-22. Sensor systems installed in the aircraft, CIPs, as well as operator consoles and instrumentation will be used to test avionics capabilities prior to release to the F-22.

Summary

In summary, the F-22 provides a revolution in avionics capability, suited to the mission and the airframe of the F-22. The avionics system design is nearing completion and key components already operational and delivered.