Code One Magazine: Desert Improvements

"The place was utterly primitive, nothing but bare bones, bleached tarpaulins, and corrugated tin rippling in the heat with caloric waves." — Tom Wolfe, The Right Stuff

Desert Improvements photo Some things haven't changed much over the years at Edwards AFB. The summer heat still sends caloric waves rippling. The wind blows constantly. The dry lakebeds extend as far and as flat as ever. Tumbleweeds still bump their way aimlessly across the Mojave. And silhouettes of Joshua trees sprout with the setting sun.

But other things have changed. Edwards is no longer the "Low Rent Septic Tank Perfection" described in the opening chapters of Tom Wolfe's best-seller. The bleached tarpaulins have disappeared. The corrugated tin has been replaced by air-conditioned convenience. Lush lawns and tall trees surround base housing. A bowling alley, an eighteen-hole golf course, and a Burger King soften the desolation. And more experimental aircraft rest permanently on pedestals than zoom through the air.

The test pilots have changed, too. They're more cerebral than cocky. Many (or most) are engineers of some sort. They're sober. They drive the speed limit. They bowl and play golf. They eat Whoppers. And when they fly, they play it safe.

Flight testing is no longer seat-of-the-pants. It is run like a business. And a prime example is the F-16 Combined Test Force, where a healthy portion of today's flight testing at Edwards takes place. The F-16 CTF, a combination of General Dynamics and Air Force personnel, develops and tests systems that improve the capability of the airplane.

"Certainly there is still risk in any test flight," admits Lt. Col. Dave Martin, who is in charge of the F-16 CTF. "But today, risk is managed. We manage it by taking a systematic approach to hazardous flights. We take incremental steps toward what we know will be difficult test points. We'll stop the test before we reach the limits of safety. We don't take unnecessary risks. We do have our problems, but most of them have not been connected with hazardous missions. They have been the types of incidents that happen in any flying organization throughout the Air Force."

Early test pilots needed more guts than understanding. The speed of sound, after all, was a barrier constructed in the minds of academics and broken by a bold pilot with no college degree. The risks were bigger, in part, because the territory was unexplored. Those early flight tests demanded brave volunteers as much as they demanded innovative engineers.

Today's test pilots must be familiar with the territory mapped by those pioneers. They are smarter. They function as interpreters between the engineers and the operational pilots. They know what to expect on a given flight. They also know how to handle the unexpected.

"A lot of engineering is used where it wasn't available before," explains John Fergione, the General Dynamics site manager at the F-16 CTF. "Ideas are tried out in a flight simulator first. While the simulator doesn't give you the whole perspective on how a particular system will work in the air, it does tell you where the hard parts are. We compare what we're getting in the air with what we encountered in the simulator. When they don't agree, we stop the test and find out why.

"Technology has done a lot for us," Fergione continues. "But there still comes a point where we don't have all the answers. If we ever got to a point where technology told us everything beforehand, I'd be out of work. Engineering still learns something when we perform flight tests. And we still encounter some surprises.

Fergione, one of two General Dynamics test pilots at the F-16 CTF, can speak first-hand of such surprises. He encountered one in 1988 while performing high-angle-of-attack tests on an F-16 equipped with a larger intake (designed to accommodate a more powerful engine).

"The change affected the shape of the front of the airplane a little," Fergione explains. "We knew it was a little more destabilizing, but the simulator indicated that everything would be okay.

Everything was not okay. Fergione went into a deep stall on his second maneuver. The spin chute failed and the airplane dropped from 41,000 feet to 16,000 before he regained control.

"That's a graphic example of taking one of those incremental steps and finding out that we were close to a cliff," Fergione says. "I had no reason to believe that I was going to get the airplane out of the stall. We theorized that as I dropped, the altitude effects helped my recovery."

The problem was fixed by some simple software adjustments to the flight control computer. The nature of that fix - software, not hardware, changes - reveals another huge difference between early and modern flight testing.

"The electronic nature of the F-16 has enabled many of the improvements," explains Mike Garland, the deputy director of the F-16 CTF. "It is easier and much less expensive to tweak electrons, diodes, and resistors and to swap out black boxes and computers than it is to make major airframe changes."

The F-16 CTF is not the only combined test force at Edwards AFB. There are CTFs connected with the F-22, the B-2, and the C-17. The F-16 CTF is, however, different from these other three CTFs in that it is connected to a mature aircraft. "The earliest objective for a CTF," Martin explains, "is to test an aircraft to provide information for making a production decision. A test force first determines if an aircraft meets its requirements."

After an aircraft goes into production, the goals shift. "We then start looking at particular systems," Martin continues. "We develop and evaluate new systems to integrate into the next block of aircraft."

Block is an important term in understanding how the F-16 has evolved. A block is a milestone in the F-16's evolution. When the airplane is upgraded in some substantial way, the block number increases. The first production F-16s, for example, were Blocks 1, 5, and 10. (All of which were later upgraded with Block 15 avionics; and most of which were upgraded with the larger tail associated with Block 15 and subsequent models).

The most modern version of the F-16 is the Block 50. Between Blocks 15 and 50 are three other general configurations - Blocks 25, 30, and 40. (There are also some variations within a block, like the Air Defense Fighter, which is a Block 15 modified with a special radar, radios, a powerful spotlight, and other devices for the air defense role.) The change from Block 15 to Block 25 involved major upgrades to the airplane's avionics. From Block 25 to Block 30, the airplane's inlet grew. A big, but less outwardly noticeable change came with Block 40 when the F-16 traded its analog flight controls for a digital system and gained a LANTIRN capability. These are just a few examples of changes that occurred from block to block.

To complicate matters, F-16s within a given block evolve as well. These block subsets (called miniblocks) are denoted by capital letters following the block number (Block 30B, for example).

Most of these improvements originate from operational and test pilots. A review board, the Multinational Staged Improvement Program's Cockpit Review Team to be exact, sorts through the ideas and determines the best ones to pursue. Military need, available space (both volume and computer capacity), and budget influence the selections. Once the selections are made, the engineers take over and turn the ideas into testable hardware and software, which then go back to the pilots for evaluation. Some advancements eventually make it into operational aircraft. Many do not. The entire process, from the submission of an idea to its operational implementation, can take up to two years. The process is accelerated for urgently needed changes.

Martin has played several roles in this process. He was a test pilot at the F-16 CTF during LANTIRN testing for Block 40. Before taking charge of the F-16 CTF, he was the chairman of the Cockpit Review Team. Somewhere between these jobs, he was an operational pilot in Kunsan, South Korea. This operational experience refined his approach to flight testing.

"Evaluating one system at a time can limit your perspective," explains Martin. "We're trying to make flight test programs more operationally significant. We do this by putting the airplane through an operational scenario as a final step to see if all the systems work well together. Because of this final step, test pilots are probably more aware of tactical operations than they were in the early days of the F-16's development."

The F-16 CTF, as mentioned earlier, is composed of General Dynamics and Air Force personnel. Some aircraft are maintained by General Dynamics. The company is involved with flight operations, flight scheduling, flight manuals, flight test, and flight control engineering. It also provides all the instrumentation engineering on the airplanes it maintains as well as providing technical representatives for all the aircraft.

"The Air Force and the contractor have both common and distinct goals," Garland explains. As deputy director, Garland is a government employee who works on the Air Force side. "General Dynamics is trying to meet its contractual requirements to the Air Force in terms of delivering certain upgrades by a certain time. We do as much as we can to help them meet that schedule. At the same time, we're here to provide the Air Force with an independent evaluation of the airplane. We have to strike a balance between meeting schedules and delivering a mature system.

"We work well together," Garland continues. "We recognize each other's requirements, and we respect each other's responsibilities. We are one of the first CTFs. We've been so successful that our organization is used as an example of how to do combined testing right."

Most of the twenty or so Air Force pilots at the F-16 CTF come from the test pilot school at Edwards after a brief tour at the 6512th Test Operations Squadron (also at Edwards) where they fly chase aircraft. These pilots are assigned to one of three branches: flying qualities and performance, current avionics, and special projects and foreign military sales. They typically stay in their assigned branch for their entire eighteen-month tour. The two contractor pilots apply their years of F-16 flight test experience to all three branches.

"In the early years, most of the Air Force test pilots had F-4 operational experience," Garland says. "Now most of them have a significant amount of F-16 operational experience. That shows how far we've come in the life cycle of the airplane."

One primary difference between the F-16 CTF and an ordinary F-16 squadron is that the CTF employs an abundance of technicians and engineers, from both the Air Force and General Dynamics.

"The General Dynamics maintainers provide a continuity that comes from their years of experience with the program," Garland says. "The blue-suit maintainers give us an operational perspective."

Garland believes that the combination explains the F-16's excellent readiness rate. "To this day, the F-16 has one of the most outstanding readiness rates of any airplane that has ever been in the Tactical Air Force," says Garland. "Early in the program, Air Force maintenance personnel would work with the GD maintainers. From their observations, they recommended changes to make the airplane more maintainable and changes to decrease turnaround time. They were often simple suggestions, like reversing a hinge point on a certain panel to make it easier to reach in and pull out a box.

"These suggestions made a big difference," Garland continues. "During Desert Storm, the pilot - not the airplane - was the limiting factor on sortie generation. Some pilots flew two or three missions a day and were exhausted, but the F-16s were ready to fly again. This was not true for other aircraft. Right now, F-16Cs and Ds are exceeding Air Force goals in terms of readiness."

Because the CTF leads the F-16 fleet when it develops something, it must take an earlier version of the aircraft and modify it for testing. The practice leads to some very unusual aircraft.

"Every one of our airplanes is highly modified," Garland explains. "Although you can't tell unless you know where to look, every airplane we have is unique. Every one has its own flight manual and checklist. We have a Block 15 airplane with Block 30 avionics and a Block 50 engine. We're doing Block 50D testing on Block 40 airplanes modified with Block 50D avionics. Our Block 40 avionics test airplanes are Block 25 airframes modified with Block 40 avionics.

By Garland's estimate, the F-16 CTF has flown over seventy permutations of the airplane. "If we run into problems on these extremely modified airplanes," Garland continues, "we lean heavily on the General Dynamics tech reps, who are connected directly with the factory."

Besides being heavily modified, the test aircraft are also heavily loaded with strain gauges and other sensors. This special instrumentation, as it is called, transmits critical information to monitoring facilities on the ground during every flight test.

Because of their unique and extreme modifications, the CTF's F-16s are dedicated to the flight test center and are rarely sent back to the operational fleet, even though the airframes tend to be relatively young in terms of flight hours when they are retired. Very few of the airframes have 2,000 hours. The oldest airframe has less than 3,000 hours.

"At most, we will fly two sorties in one day on an airframe," Fergione explains. "Sometimes, we'll fly it once a day and take the next day off to review the data. The operational Air Force will fly an airframe three and four times a day. A good rate for us is three to five flights per week. But they are hard hours. We're often taking the airplanes out and flying them to their limits."

The F-16 CTF has been successfully bending F-16 airframes for a long time. The organization can trace its history to January 1974 when the YF-16 first lifted into the air above the runway at Edwards. While some people may think the airplane has reached its prime, you're not likely to find any of those people at the F-16 CTF.

"I tend to think the F-16 will be around a long time," says Fergione, who has been with the F-16 at Edwards since 1982. "I guess there comes a point where you say, 'That's it. We're not doing any more.' But I don't see that coming yet. The Air Force may be forced to that point before it is ready. Your guess is as good as mine on how defense money will be spent in the next few years."

But tighter funding may be the airplane's saving grace. "The Air Force is getting one hell of a machine for the money," says Garland. "The F-16 is a classic example of getting more bang for your buck. And the logistics tail, a very costly item, is in place. Creating a new logistics system is very expensive.

"I think that there is still growth in the airplane," continues Garland, "especially given our current funding crisis. Of course, there are other considerations beyond the black-and-white logic of the cost, quality, and capability of a given system. "

Lt. Col. Martin echoes these opinions. "Right now the Block 50 has a tremendous capability," says Martin. "The initial design of an airplane is critical. The F-4, for example, went many years before technology surpassed the airframe. We haven't reached that point with the F-16. Advancements in aerodynamics, aeronautics, and aero-elasticity have not passed the airplane.

"Because it is a small airplane," Martin continues, "we have limited space for computers. But as computers advance, they get smaller and we can fit a much larger capability into the same space. We haven't reached the limit on avionics and weapons incorporation. And engine advancements are keeping the thrust-to-weight ratio right where we like it, so the airplane has maintained its maneuverability. Even with this increase in weight and power, we have not exceeded the structural limits of the airframe. We built a strong jet from day one - a jet that you could turn nine g's without overstressing. We have an airplane that we can take into the future as long as there is support from those who make the decisions."