Lt. Gen. Mike Loh, Commander of the Air Force Systems Command's
Aeronautical Systems Division, attributes that significance to the Advanced
Tactical Fighter, a futuristic craft that ASD is set to begin flying in
prototype form next year.
General Loh means that the innumerable revolutionary
aerospace technologies now being stimulated and perfected by the high-profile
ATF effort will feed the Air Force's appetite for developing new fighters on a
For example, standard F-1 6s and F-15s, destined for heavy
duty into the next century, may receive ATF-type engines and avionics. Even
"low-observable" technologies that provide "stealthiness"
for ATF might well be infused into either or both of these aircraft.
"Absolutely," claims General Loh.
"Applications of low-observable technology to those aircraft can happen.
. . . We're studying all of that now. We see lots of mileage in F-15s and F-16s
as we bring ATF along."
Further in the future, say officers, more ATF technologies
may work their way into a proposed Agile Falcon makeover of F-16, the Air Force
version of the Navy A-12 Advanced Tactical Aircraft, future ATF clones, and
other airplanes not yet in public view.
"The ATF is far more than just a single aircraft
development program," claims General Loh. "The ATF is bringing along
with it the whole technological base—avionics, structures, materials, flight
controls, engines, cockpits, microprocessors—for future fighters."
Fueling the revolution are ATF's awesome goals. Plans call
for ATF not only to be able to elude detection, cruise at supersonic speeds without
afterburner, take off over short distances, and handle better than any other
fighter. It will also have to be reliable and easy to service, with its
avionics blended in ways once thought impossible.
Whatever the precise makeup of the final, production-line
aircraft, however, this much is certain: The air-superiority ATF shapes up as a
technological progenitor in the same way that its predecessor, the original
F-is Eagle, was father to many technologies that have found their way into the
F-16, F- ill, and F-15E.
In light of ATF's development cost of $9.9 billion (measured
in 1985 dollars), Air Force officers are promoting the airplane's broader
legacy as a distinct political plus. "This is a point people often overlook,"
General Loh says. "Development of ATF is expensive. There is no doubt
about it. But the payoff goes well beyond ATF itself."
Helping to make the payoff possible, for ATF as well as its
aeronautic friends, has been the pioneering work by ASD technologists at
Wright-Patterson AFB, Ohio, and its many aerospace contractors.
Picking Up Momentum
The ATF project itself is picking up momentum. Prime
contractors Lockheed (teamed with General Dynamics and Boeing) and Northrop
(teamed with McDonnell Douglas) are far along in competition for a $7 billion
full-scale development contract that will be awarded in January 1991.
They are nearing the moment of truth in a fifty-month
demonstration and validation phase aimed at reducing ATF's development risk.
Each is fabricating two prototype airframes—Lockheed's YF-22A and Northrop's
YF-23A—that must be ready to go no later than early 1990 for a year of flying.
The primes also must complete ground-based prototypes of ATF's avionics in time
for critical demonstrations starting late this year.
Similarly, ATF prototype engines are nearing completion at
power-plant builders Pratt & Whitney and General Electric. Three models of
their respective engines, the P&W YF1 19 and the GE YF12O, are being
hammered together for use in both ATF airframes.
For Col. James A. Fain, Jr., ASD's program director for the
ATF, progress to date leaves little doubt that the prototypes will be ready on
schedule. "We are definitely going to get an aircraft into the air in
early 1990," reports Colonel Fain. "No question about that."
Although the details of ATF's proposed flight
characteristics, signatures, and electronics are heavily classified, there can
be little question that it will be a fighter of unprecedented power.
The Air Force isn't budging from its position that the ATF
must possess a unique first-look, first-kill power—the ability to find and
kill a foe before being targeted in return—among other attributes.
That's for the future. What ASD will be looking for in its
prototypes, reports General Loh, will be a demonstration of "supersonic
cruise without afterburner in a low-observable-shaped planform that exhibits
fighter handling qualities and fighter maneuverability."
What gives ASD officials confidence that they can do what's
never been done before is the array of new technologies that the ATF effort is
both extending and bringing to life.
One obvious area of high-technology exploitation for
ATF—and for its aeronautic descendents—concerns development of advanced airframes.
The ATF's contractors and associated ASD laboratories now
are deeply engaged in a multifaceted exploration of structures, materials, and
flight controls. The goal: Use advanced technologies to reduce ATF weight,
drag, and signatures and in the process meet USAF's unyielding demand for a
resilient, hard-to-spot, extremely agile air vehicle.
Evidence is they are succeeding. "The airframes are
coming together," reports Colonel Fain. "We're comfortable with how
they're going to build the airframes, what kind of materials they'll use."
One result will be highly advanced flight controls. The ATF
contractors are pushing the state of the art in the technologies of fiber
optics, digital fly-by-wire electronic controls, and the like to improve aircraft
handling and stability. Explorations proceed into possible use of
"active" wing surfaces. Also among technologies being explored are
self-repairing flight-control systems that would permit an aircraft to
complete its mission even after being damaged in battle.
Development of advanced materials is also getting a boost.
For more efficient aerodynamic and structural design with reduced weight, plans
call for widespread use of composite materials—as much as fifty percent of the
total airframe. Areas of interest include graphite epoxy, thermoplastics, and
carbon structures—materials that will impart great strength and endurance
without adding much weight or cost.
The ATF's greatest contribution may come in the area of
advanced "low-observable" technologies needed to reduce the aircraft's
visual, electronic, and infrared signatures. Conformal sensors and internal
weapons carriage will help. Also under way is exploration of advanced coatings
and radar-absorbing materials. Some believe the ATF's radar cross section will
be a small fraction of the F-15's.
Colonel Fain ranks low observables among the most critical
technologies being developed in the ATF airframe during the demonstration
phase. He is confident that a significant degree of stealthiness can be
achieved without sacrificing ATF's performance.
"We're working on the last ten percent" of the
equation, he says. "I haven't found any major hiccups, major disasters,
major problems, working that last few percent. I think we know pretty much
where we are in the LO arena. . . . We are going to have a low-observable aircraft
that will be blended with the other attributes of the aircraft to give us a
very effective weapon system."
ATF's engine requirements also promise to bring about a
major boost in advanced propulsion technologies applicable to future fighters
no less than to ATF itself. In simplest terms, engine technologists are
finding ways to increase the thrust, stabilize the weight, enhance the
flexibility, and expand the reliability of a powerplant.
Research by ASD and its contractors is producing
high-strength, heat-resistant alloys and cooling techniques, plus new turbine
blade designs and combustion technologies. These are expected to enable ATF's
engines to develop thrust of 32,000 pounds or more.
At the same time, the weight of the engines is being kept
within bounds, possibly by use of new nonmetallic materials. The ATF engines
will have fewer parts, perhaps forty percent fewer, than engines of today.
Taken together, these factors are expected to enable the ATF's
power-plants to far outpace those of the F-15 and F-16 in terms of their
thrust-to-weight ratios at supersonic speed and at high altitudes. This will
permit the new fighter to cruise at supersonic speeds, somewhere between Mach
I and Mach 2, without using the afterburner. Specific fuel consumption thus
will decline. Such "dry" supersonic flight will give ATF a much
wider combat radius and fighting energy.
Both prototype engines, based initially on technologies
developed in the ASD Aero Propulsion Laboratory's Joint Advanced Fighter Engine
program, are in altitude testing. Colonel Fain is satisfied with their
progress. "They look good," he says. "I don't see any major problems."
Other new technologies are expanding the ability of an
aircraft to vector the direction of its engine thrust. A key to this feature of
ATF is development of advanced engine nozzles and control mechanisms.
The prototype nozzles to be installed on the twin-engine
aircraft will demonstrate an ability to vector thrust by twenty degrees, up or
down, in the same or opposite directions. Once perfected, this feature would
provide the ATF with short-takeoff capability and the power to make tight turns
at high speeds, among other maneuverability attributes.
The mating of engines and airframes shapes up as yet
another ATF technology. The problem: How to integrate the engine/nozzle complex
with the airframe in ways that will provide performance over a large flight
envelope—from subsonic to supercruise, high to low altitude—and also reduce
drag and signatures. The answer is anything but clear.
"We're concerned about engine/ airframe
compatibility," reports Colonel Fain. "We've got a lot of work to do
in that area."
The same could be said of the Advanced Tactical Fighter's
exotic, supersophisticated avionics suite, a system that will lie at the heart
not only of this fighter but also, in all likelihood, of future ones.
Much work remains in the incomparably tough task of
creating a totally "integrated" layout. The effort entails pulling
together all functions and support technologies in a coherent system of
thoroughly blended elements that will make today's disjointed systems obsolete.
The prize is great: a single central nervous system capable
of coordinating sensors, flight and propulsion controls, weapon controls,
cockpit displays, and countermeasures. The payoff would come in the form of
powers for detecting, identifying, and engaging foes beyond visual range,
enhanced situational awareness, expanded self-defense, reduced signatures,
higher reliability, lower pilot work load, and lower cost.
In pursuing that goal, ATF developers have turned the
airplane program into a huge "kicker"—financial and otherwise—for
technologies that hold the key to future avionics effectiveness.
Among the technologies being evaluated are next-generation,
very-high-speed integrated circuit (VHSIC) chips; advanced multi-mode,
active-element-array radars; shared apertures; shared antennas; laser ranging;
infrared search and track; "smart-skin" sensors; advanced cockpit
displays; voice-recognition systems; fiber optics; and systems of artificial
Awesome Amounts of
In a very real sense, the technology most critical to the
integrated avionics system is integration itself. The ATF's developers are
devising means for fusing awesome amounts of data from multiple sources to provide
reliable, instantaneous satisfaction of needs, from target classification and
weapon selection to optimum flight path.
Within the framework of Pave Pillar architecture developed
at ASD's Avionics Laboratory, ATF contractors are developing VHSIC common
signal processors to communicate with and tie together such avionics elements
as radar, infrared search and track, and collections of major offensive and defensive
The latter include Integrated Electronic Warfare Systems
(INEWS) and Integrated Communication Navigation Identification Avionics
(ICNIA), both under development for years at ASD and avionics houses.
Colonel Fain and his chief avionics deputy, Lt. Col. John
Borky, make it clear that no INEWS or ICNIA "black boxes" themselves
will make it into the system. They are viewed as technologies only,
technologies that will be incorporated, to a greater or lesser degree, in
common modules run by VHSIC processors and high-speed data buses.
This, in the words of one ATF officer, amounts to "a
massive change in the way we do business" in avionics. The benefits are
that modules selected from a limited variety of multipurpose units could be tailored
for specific requirements. They would eliminate many sources of avionics
failures by using fewer cables and connections. As small units with common
specifications, they could be built by a large number of contractors, thereby
ensuring competition and lower cost.
The entire approach is experimental. The principal risk is
that, in the new world of integration, one contractor working on one piece of
the avionics puzzle may be proceeding along an altogether different path from
those working on others.
Fears of this type were eased in recent months by some
startling successes. Example: When a piece of applications software written by
one ATF contractor was installed in a processor built by another, they played
together harmoniously on the first flip of a switch. That came as a mighty
relief to ATF officials.
"I didn't expect 'em to plug the software in and make
the thing turn on right away," says Colonel Fain. "That's very
positive. Very, very positive for my very, very cautious approach to
Even so, officers say all avionics elements may not be ready
for the first ATFs that become operational in 1995. More broadly, while the
basic goals for ATF remain unchanged, it will not possess each and every one
of the features laid out for it originally. As ATF officers have acquired more
hard data, trade-offs have been made.
"Our expectations for ATF have been lowered over the
past two years," explains General Loh. "With any 'paper' airplane,
expectations are always somewhat higher than the reality. That was true of the
Elimination of some features was in keeping with a
50,000-pound weight objective that the Air Force has set for the ATE
Elimination of others was associated with a limit of $35 million, in unit
flyaway cost, that USAF has set. The service wants to build 750 ATFs at that
price in 1985 dollars based on a production run of seventy-two fighters a
year. Because weight usually means cost, the two limits are obviously
Saving Weight and
Last fall, Air Force leaders undertook a major review of
the ATF's performance goals to determine where to save weight and money, making
a number of specific design decisions.
In earlier reviews, ATF transonic maneuvering capability had
been reduced by one-half G, and the fighter's internal weapons carriage was
lowered somewhat. While it still wants a short-landing capability, the Air
Force dropped its requirement for thrust reversers when it learned that they
would add significant cost and weight to the aircraft. Now, ATF will make short
landings by using mobile, ground-based arresting barriers that are scheduled
to be put in place for other aircraft.
Such technology trade-offs are painful. More are yet to
come. Says Colonel Fain: "We will continue the requirements refinement
process throughout dem/val. The requirements will be based on the threat, the
cost, and the weight. It is very important that we provide the senior
leadership with the best possible aircraft within the cost and weight goals
established for the program."
Some observers outside the Air Force, however, speculate
about whether the cost and weight figures are firm, unchangeable limits or
less-than-ironclad goals. They suggest that the Air Force can ill afford to
build a less-than-adequate airplane just to stay within those limits. Faced
with a choice, it is possible that USAF could ease cost and weight limitations
The ATF's basic performance characteristics will have
implications not only for ATF itself. They could affect the politically
difficult proposal for the Navy to make use of ATF's technologies.
Under pressure from Congress, the Navy is committed to take
a serious look at using a "wet" variant of ATF—a Naval ATF, or
NATF—to replace its F-14 Tomcat fleet defender at the turn of the century.
Few question the financial benefits. In taking this step,
claims the General Accounting Office, the Navy could avoid the $7 billion cost
of developing its own new fighter.
But the Navy has been keeping a close and skeptical eye on
the suitability of the Air Force's plane for Navy missions. Some Navy officers
had suspected—and some continue to believe—that ATF's capabilities are being
compromised in pursuit of arbitrary cost and weight goals.
Officially, the Navy is committed to trying to make NATF a
reality. The service last summer assigned a Navy team to Wright-Patterson to
oversee development of preliminary system specs. The Navy also has provided
funds to Northrop and Lockheed to begin a more detailed look at a possible Navy
design. It will participate in ATF source selection, with suitability of
design for NATF the uppermost consideration.
"We've just gotten the Navy ATF program started,"
notes Colonel Fain. "But while we've been looking at Navy compatibility
for a couple of years, it's been at very high levels. Based on that, we don't
see major show-stoppers."
He sees no significant problem with the Navy's use of ATF
avionics or engines. The NATF airframe is a different story. The Navy wants a
much larger wing that is capable of changing shape for carrier storage. The
plane will need heavier landing gear for carrier use, and this will require
heavier beams to be added to NATE This, he says, can be accommodated.
Colonel Fain refuses to speculate on whether the Navy will
make a "firm, in-blood commitment" to the NATF—a decision that could
reduce ATF procurement costs by as much as $2 billion due to economies of
scale and therefore ease the cost pressures on ATF designers.
Colonel Fain is taking nothing for granted in this respect.
"Let me put it to you this way," the Colonel says. "I have been
working up our program without the Navy in there. If the Navy does come in,
and all of this [cost reduction] comes to fruition, then we can come in and
take advantage of that. But I'm not counting on that right now. If I did, and
was wrong, then I've got a program that's not executable."
The fate of NATF aside, Air Force leaders are now
establishing formal technological links between their premier fighter program
and a number of other USAF projects. The moves are aimed at solidifying the
combat strength of future aircraft by ensuring that they benefit from ATF
The Case of the F-16
The key case in point is the F-16 multirole fighter.
Beginning with a directive from Deputy Defense Secretary William H. Taft IV
last year that instructed the Air Force to consider ATF technologies for
future variants, USAF officials have embraced the concept.
"We'll get a big payoff for the F-16," says
Maj. Gen. Robert Eaglet, director of ASD's F-16 program
office, puts it this way: "We need to examine mechanisms to provide for
the transfer of technology from ATF to F-16. We've looked at that very aggressively,
and we're excited about that."
The ATF technologies would benefit a planned variant of F-16
dubbed the Agile Falcon. Proposed for initial delivery in 1995, the Agile
Falcon would feature larger wings, more powerful engines, and newer avionics.
The program is intended to strengthen the F-16 against more
powerful Soviet fighters of the next decade. The US also is offering to develop
and produce the plane with the Netherlands, Belgium, Norway, and Denmark,
original partners in production of the F- 16. All four and the US have entered
into a two-year predevelopment study agreement ending in 1990. General Dynamics,
the F-16's maker, estimates research costs at $600 million.
General Eaglet says that ATF's engine or a derivative could
be fitted into Agile Falcon, or it could be used as a design basis for a new
ATF-type engine. Also in prospect could be installation of highly advanced
low-probability-of-intercept radars and enhanced ATF-type avionics. It is no
stretch of the imagination to see some of ATF's low-ob servable technologies
in later versions of the Agile Falcon.
Currently, the Air Force is pursuing modest versions of
Agile Falcon for its first phase. Later versions will make heavy use of such
ATF concepts as modular avionics architecture. Due to high cost, some of the
advanced ATF equipment or components may be unaffordable in the beginning. But
officials expect they can be put in later Agile Falcon models and the earliest
models can be retrofitted.
"There are lots of [ATF] technologies that already
have been flight-demonstrated and can be put into production at roughly the
same time as the Agile Falcon," says General Eaglet. "The highly
advanced technologies, ones that are being flight-tested and proven for the
first time in the ATF program, may be introduced later."
Agile Falcon design already has evolved considerably. First
proposed in 1987 by General Dynamics, the new craft was to increase the
original F-16's wing surface from 300 square feet to 375 square feet. Now, the
figure has grown to 400 square feet. Leading-edge sweep also has been changed.
Officers say the bigger planform, bringing higher agility, would be useful in
either air-to-air or air-to-ground combat. In fact, says General Eaglet, the
aircraft could turn out to be a strike fighter adept in both regimes.
"You'd probably call it an 'F/A- 16,' like the Navy
calls its plane the F/A18," he explains. "For the most part, the
aerodynamic and engine improvements we're considering for Agile Falcon appear
to help the air-to-ground capabilities just as much as they help the
That is fortuitous. The Air Force appears determined to use
some form of the F-16 as its replacement in the 1990s for the A-10 close air
support aircraft. A Close Air Support Aircraft Design Alternatives study,
performed by ASD and presented to Air Force and Pentagon leaders last fall,
reinforced the view that the "A-16" would meet Army CAS requirements.
The A-16 could be the Agile Falcon itself. The A-16 could also turn out to be a
"missionized" version of the standard F-16, optimized with
technologies that aid in the ground attack mission.
General Eaglet foresees a virtually endless parade of F-
16s coming into production over the next decades. The reason is simple: USAF
needs a low-cost, lightweight complement to the ATF for air superiority and
for ground attack. None other than the F-16 is in prospect.
In this circumstance, as in others, diffusion of
technologies made for the ATF itself shapes up as an increasingly critical
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