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Computer Technology and the F-22 Fighter
By Robert F. Dorr

Those who come face-to-face with the Air Force's F-22 fighter are struck by its size and shape. The F-22 is big for a single-seat jet. It looks fast - "like it's flying at Mach 2 just sitting on the ground," one reporter wrote, stretching a hackneyed cliché. Thanks in large measure to computer technology, the Lockheed Martin/Boeing F-22 Raptor looks like, and is, a marvel of modern science. Yet when the fighting begins, this plane is meant to do a job as old as war itself.

"The fighter pilots have to rove in the area allotted to them in any way they like, and when they spot an enemy they attack and shoot him down; anything else is rubbish." So said Baron Manfred von Richthofen, the legendary World War I flying ace, who went into battle in a rickety, sputtering airplane with no radar, no avionics and no computer.

In the digital age, the fighter pilot still wants to win in battle. Moreover, Air Force doctrine seeks not just air superiority, but air dominance. "We want the other guy to quit in the bottom of the first inning and go home," says Jeff Rhodes of Lockheed Martin, the company that assembles the F-22 in Marietta, Ga.

Rhodes points out that three goals formed the bedrock of the F-22 program when it was launched in the mid-1980s, and that not one of them could have been achieved without giant strides in computer technology. The guidelines: "(1) exploit information; (2) deny information to the enemy; and (3) achieve overwhelming lethality."

The F-22 Described
The F-22 Raptor - the nickname was chosen after Lightning II and SuperStar were rejected - is 62 feet, 1 inch in length, just two feet shorter than a DC-3 transport. Air Force leaders hope the F-22 will destroy its adversaries beyond visual range (BVR) by "painting" them on radar and killing them with long-range missiles. In the past, fighters carried a second crew member to operate the all-important radar, but because system integration permits simplicity, the pilot can be his own radar operator without suffering "task saturation." The Northrop Grumman/Texas Instruments (formerly Westinghouse) AN/APG-77 radar introduces a whole new technology - the first active-element, electronically scanned system to be used on a U.S. fighter.

The F-22 is pushed through the sky by two Pratt & Whitney F119-PW-200 turbofan engines with afterburners and two-dimensional thrust vectoring nozzles. Each engine creates 35,000 pounds of thrust, equivalent to the power of a railroad locomotive. When the Raptor made its official debut at a "roll out" ceremony in Marietta on April 9, 1997, bigwigs deemed the engines important enough to warrant an entire chapter in the briefing book handed out to reporters. The engine was developed in a design process that used a team approach and is called Integrated Product Development (IPD), a close cousin of the computer-based process that produced the fighter itself (of which, more momentarily).

With F119 engines, the F-22 Raptor is the first fighter capable of "supercruise" - that is, the ability to maintain a speed faster than sound while proceeding to and from a target. As for those nozzles at the tailpipe, they divert engine thrust as needed to make the F-22 extremely maneuverable. Never previously installed on a production aircraft, the nozzles can vector thrust 20 degrees up or down, thanks to precision digital controls. They enable the F-22 to turn or roll 50 percent faster than current fighters. In an ideal world - fighting beyond visual range, remember - the enemy will never see the F-22 at all. But in a close-quarters brawl the F-22 can out-turn, out-roll and outmaneuver any other fighter in the world. After traveling faster to get into the fight, the F-22 uses modernized versions of proven weapons to win it.

The internal weapons bay accommodates six radar-guided AMRAAM (Advanced Medium-Range Air-to-Air Missiles), side bays hold two more AIM-9 Sidewinder heat-seeking missiles, and - just in case it does have to fight close-in - the F-22 has an M61A2 20-mm. cannon.

Fighter Mentality
Even in the digital age, the most important component of a warplane is its pilot. Fighter pilots wear bright-colored scarves, kick the tires, and "light the fires" - that is, start up and take off. In the past the "fighter mentality" required a rough edge, and many bragged, caroused and drank. No one would have ever confused a hard-charging fighter jock with a computer nerd. But in today's cleaner, spiffier Air Force, fighter pilots are information warriors, and the F-22 Raptor is the first combat plane designed to exploit information. The F-22 gathers information from many sources and weaves it into an intuitive picture of the tactical situation that the pilot can quickly grasp.

The traditional stick, rudder pedals and throttle on the F-22 may be little different from those on von Richthofen's wood-and-fabric biplane. However the F-22's avionics architecture was designed from day one to provide information-handling capability - without locking the design into any particular use of equipment or capabilities available when the program began in 1985, when the plane flew in 1997, or when it enters service in 2004. "If I had to pick one Œsilver bullet' that makes the F-22 different, I would pick the way we've used computer technology to build in flexibility," says Tom Burbage, Lockheed Martin program director. "I just can't place enough stress on the open architecture which makes it possible to continually update the aircraft without replacing hardware."

The F-22 was designed at a level of technology that moved beyond traditional design approaches. The common thread to making an aircraft 25 years more advanced than its predecessor - solving technical and organizational challenges of running the program and implementing the three points of the F-22 design approach - lies in the extensive use of computers. To put F-22 technology into perspective, the computer used in the Lunar Module operated at 100,000 operations per second and had 37 kilobytes of memory. Today, the F-22's main mission computers, which are called Common Integrated Processors, or CIPs, operate at 10.5 billion operations per second and have 300 megabytes of memory. Just imagine: That's 8,000 times the memory and 100,000 times the computing speed of the Apollo 11 moon lander.

The Hughes-built CIP is the "brain" of the Raptor's avionics system. Rather than radar, the electronic warfare system and the avionics system having individual processors, the CIP - the size of an oversized bread box - supports all signal and data processing for all sensors and mission avionics.

Not a 286 Model
Work on the F-22 began seriously in 1986. That is when the CIP began to evolve. That year, the IBM 286 computer was just coming into service with the general public. Thinking not about what was possible but about what might only be dreamed of, engineers sketched out the future F-22 to meet computing goals that seemed unattainable. One of them paraphrased a famous truism by science fiction giant Arthur C. Clarke: "If a distinguished scientist tells you it can't be done, he is probably wrong. If a techno-nerd at Lockheed says it can be achieved, he is probably right."

For instance, a fiber optic transmitter and receiver (FOTR), a part of the display avionics, was roughly the size of half a sheet of paper in 1986. By 1990, that same computational power had been shrunk to the approximate size of today's floppy disk. The engineers working on the future Raptor began to feel confident they might achieve their ambitious goals.

Today, that same computing power has been packaged into a small device only slightly bigger than a postage stamp (66 of these modules make up the CIP's "breadbox"). The size, weight and power requirements for these types of modules continue to drop.

There are two CIPs in each F-22 - again, with 66 module slots per CIP. They have identical backplanes, and all of the F-22's processing requirements can be handled by only seven different types of processors. Currently, 19 of 66 slots on CIP 1 and 22 of 66 slots in CIP 2 are not populated and are available for processing.

This quantum leap in computer technology is not limited to the F-22 aircraft itself. Computational power has greatly changed the use of computers in all aspects of the F-22 program from design through manufacturing, and even the testing of the airplane.

More on the CIPs
Of all the advanced engineering that went into the F-22, the integrated avionics system is perhaps the most impressive. At its heart are CIPs that do all the signal and data processing for the sensors and mission avionics. The F-22 will have two CIPs, as well as space, power and cooling for a third to handle future growth. Each of the immensely powerful CIPs has nearly the throughput capacity of two Cray supercomputers.

All information from inside the aircraft - such as the functioning of systems, weapons availability and engine situation - is combined with data from outside the aircraft (radar returns, for example) and is presented to the pilot in an easily-read display.

The F-22 is equipped with what program director Burbage calls an "intranet system," which will allow all F-22s in a fight to share data with the other aircraft electronically. This capability enables one F-22 to turn on all its sensors and provide data to other F-22s, which need not radiate and thus risk detection.

Engineers conceived the F-22 cockpit as a workstation enabling the pilot to devote full attention to the information from the integrated avionics system. Most of the avionics system uses common components and modules and standard buses. A modular approach enhances fault tolerance and eases requirements for expansion and reconfiguration in the future.

Manufacturing the F-22
The F-22 is more than an airplane. It is a program - potentially, one of the costliest military programs of all time. There are plenty of critics of the Air Force's plan to order 339 Raptors to replace the McDonnell Douglas F-15 Eagle and make them operational beginning in 2005 - at a staggering cost of $138 million per airplane (vis-a-vis $215,000 for a P-51 Mustang fighter in World War II). Proponents say costs are being held in check - and all indications are that the program is, indeed, being run responsibly.

Moreover, proponents argue, costs are less than they might be otherwise, in part because the F-22 effort uses a basket of configuration management (CM) tools. Using integrated digital technology to manage a program is not new, but with the F-22 CM has been taken a step farther. From its first moment on the drawing board (not really a board at all, but a computer), the F-22 program has been controlled by a refined version of CM known as process configuration management (PCM).

The need for management is obvious: More than 40 software suppliers are developing software for the F-22 effort. Just to cite one statistic, the instructions for the F-22 flight operations and weapons program will require about 1.6 million separate lines of computer code. It would have been impossible to conceive, design, develop, build and test this Air Force fighter without process configuration management software (PCMS). The F-22 program acquired PCMS from SQL Software of Vienna, Va., picked by Washingtonian magazine as one of 20 companies to watch, and headed by software expert Tani Haque.

A New Process
As a revolutionary step forward, Haque likens PCM to the factory mass-production technique introduced by the automotive world's Henry Ford. "Ford had to innovate to meet huge demand. He created a process. He asked, ŒHow do I build cars?' Instead of moving people around, he invented the production line."

PCM is every bit as innovative, says Haque."PCM is a closed loop configuration management system, which enables organizations to organize and manage the changes affecting their software, hardware and documentation assets more efficiently." Previously - even as recently as the F-15 program - one department did not always know what another was doing, design changes did not reach all workers simultaneously, and thousands of hours were wasted on meetings just so people could talk about work that was already finished.

PCMS has eliminated nearly all review board meetings by the F-22 team. "This can save days, weeks, even months," says Haque. Review-based meeting announcements and minutes have been eliminated because the meeting announcements are automatically generated by PCMS and the minutes are captured by PCMS. Paper flow has been all but eliminated. Haque regrets that, elsewhere in industry, not everybody is paying enough attention to the need for such measures. "A company will put a first-rate financial system in but short-change itself by not having a good system for controlling software. It happens all the time."

According to Tom Burton of Inroads Technology, Inc. of Santa Barbara, Calif., manufacturers will often buy a software tool from a supplier, install it, and then announce to the world that they have configuration management in place. It is not that simple, insists Haque, who sees a four-step implementation approach:

First comes analysis. "That's a detailed series of steps to make sure people understand what their requirements are," says Burton. "They have to know where problem areas are and look at the application they are developing to understand the software environment."

Second is process design. Based on a manufacturer's requirements, experts create a software change workflow and a detailed configuration process audit and tracking procedure. "We nail down a step by step process," explains Burton.

Third comes CM tool implementation. "The first time we touch the tool, we determine which part of the process can be automated. We make sure the tool is set up correctly, pointed toward the right software environment."

Fourth, and only then, is what Burton calls "Roll Out": "We make sure the company is prepared for this new way of doing business. Roll Out includes training, education [and] making [employees] aware of what we're trying to accomplish." Burton believes the F-22 effort is successful because the plan in effect includes Step 4.

When an F-22 flies over - we shall have to wait until about 2003 to see this dramatic new fighter at an air show - the role of computer technology in the Raptor will be invisible to the human eye. Like those motherboards in your home computer that, perhaps, you never even glance at, the beauty of the F-22 lies beneath the skin. The Lockheed Martin F-22 Raptor is a formidable flying machine and would be nothing without the digital miracles that design it, build it and fly it.