technology as a whole. In the decade which followed, and the first combat use of stealth, this changed.
At the end of the 1990s, as this is written, stealth is no longer the first and only design consideration. Rather, it must be balanced with the more traditional requirements of speed, range, payload, weight, maneuverability, and cost. More important, stealth was no longer hidden behind a wall of secrecy. The concept was now integrated into the mainstream of aircraft design, rather than being a separate 'Black' aspect. The F-l 17A, B-2 and the F-22 are all openly on display at the annual Edwards AFB air show, as are the stealth UAVs, the GNAT 750, Darkstar, and Global Hawk.
An example of the changing view of stealth is the F-22 fighter. In today's air combat, the preferred method is a first-shot kill with long-range air-to-air missiles.
Historically, most pilots lost in air combat were shot down by planes they never saw. The F-22's stealth features are an extension of this, giving it the ability to destroy an enemy plane, without warning, with a missile fired from miles away. If the ability to make a long-range kill was the only consideration, then a pure stealth design would serve.
In a close-in dogfight, however, a pure stealth-centered design would be at a disadvantage, as it could be slower, underpowered, and much less maneuverable than its conventional opponents. In the case of the F-22, the designers were unwilling to totally compromise its performance in the name of stealth. Several features of the F-22 increase its radar cross section, but that was the price for better maneuverability.
Although the basic shape of the aircraft may be the primary driver of stealth, the design considerations now include existing airframes. An aircraft's RCS can come from relatively small features, such as a gap in an access door. It therefore makes sense that a 'clean-up' program, involving discovery and fixing of such reflection sources, as well as addition of Radar Absorbing Material to areas such as intakes, could result in a militarily significant reduction in a plane's RCS. The prime example is the B-IB. This was a redesign of the original B-1A to incorporate a reduced RCS. Subsequently the 'Have Glass' program was undertaken in the late 1990s to add stealth features to F-16 fighters. Although this cannot give an F-16 the tiny RCS of a true stealth aircraft such as an F-l 17A or a B-2, Have Glass has made F-16s much more difficult to spot in air-to-air engagements.
The effect of both the more balanced design philosophy and the addition of stealth to existing airframes is to blur the boundaries. In the 1970s and 1980s, there were stealth airplanes, and there were conventional airplanes. The boundaries between them were fixed and rigid ones of secrecy and technology. Today the lines are not hard and fast. Is the F-22 a stealth aircraft? Yes, without question, but not in the same ways as the F-l 17A or B-2. Are the B-lBs and Have Glass F-16s stealth aircraft? No, but they are stealthier now than when the prototypes made their first flights.
A different factor influencing the future of both stealth and military aviation is the increasing importance of cruise missiles and UAVs. Like stealth, the cruise missile concept dates to World War I. The first was the 'Kettering Bug,' a small pilotless biplane built by the U.S. Air Service for attacks on Germany. It entered production in the final months of the war, but did not see action before the Armistice.
World War II saw wide-scale use of V-l missiles by Nazi Germany. During the 1950s and 1960s, the air force operated Mace and Matador cruise missiles, while the navy Regulus cruise missiles were based aboard ships and submarines. The problem with all these weapons was a lack of accuracy. They could only strike area targets, such as cities or airfields with nuclear weapons.
In the late 1970s, at the same time as the stealth breakthrough was made, the development of scene- matching guidance systems changed this. The missile could now find its way to a target by matching specific landmarks, in order to correct its flight-path. A navy Tomahawk or air force Air Launched Cruise Missile (ALCM) could navigate hundreds of miles, taking an evasive course to avoid air defenses, and then hit a specific building in the heart of a city.
They were seen as strategic systems, designed to attack targets inside the USSR with nuclear weapons. The threat facing them was the massive Soviet air defense system. The Tomahawk and ALCM could both be spotted on radar. Even their small size and low-altitude flight could not guarantee their survival in the face of hundreds of S AMs. The need was to make the cruise missiles harder to detect, enabling them to strike even the most heavily defended Soviet targets. The technology to do this had already been developed for the Have Blue.
The initial stealth cruise missile tested was Lockheed's Senior Prom. Although this program is still Black, it is reported that the Senior Prom missile was a smaller version of the Have Blue. It was designed for carriage by B-52s. It is further understood that the 'Hangar 18' building on the Groom Lake flight line was actually built to support this program. With the B-52 inside the hangar, the test missiles could be loaded aboard without being seen. The Senior Prom program was subsequently canceled, however.[853] Its replacement was the Advanced Cruise Missile (ACM). The ACM resembles a larger Tomahawk, but with a faceted nose, a flush air intake, and forward swept wings and small tail surfaces to reduce its RCS. [854]
Subsequently, another stealth cruise missile entered development, Northrop's Tri-Service Stand-Off Attack Missile (TSSAM). Just as Senior Prom used the Have Blue shape, TSSAM had the same shape as the Tacit Blue, only turned upside down.
While the Tacit Blue was called 'The Whale,' the TSSAM became know as the
'Killer Whale.' According to one story, persons joining the program were given an initial briefing using a 'model' of the TSSAM to illustrate its odd shape. This model was a Twinkie with cardboard wings and tailfins. (This same Twinkie was used throughout the several years the TSSAM program continued, saying something presumably about preservatives.) The TSSAM carried a conventional warhead, had a highly advanced terminal guidance system, and was designed for use by a number of aircraft, including the B-52, B-2, F-16, and FA-18. However, like the Senor Prom, TSSAM was canceled.[855]
While the various attempts to build stealth cruise missiles have met with mixed results, with Senior Prom and TSSAM never entering production, and the number of ACMs built were limited, the role of the cruise missile has grown. The scene matching guidance system was originally designed to allow a much more accurate strike with a nuclear weapon, increasing the probability of destruction. This guidance system also allowed tactical strikes using conventionally-armed cruise missiles. This increase in accuracy was essential for the missile to have any utility, due to the small warhead size.
Tomahawks and ALCMs were used in Desert Storm, and they have been the weapon of choice for reprisal raids, including Desert Fox. They have the advantage of accuracy, to minimize civilian casualties, while being unmanned, their use does not pose the risk of U.S. pilots being captured or killed. At the same time, stealthy UAVs were under development for reconnaissance missions. Unlike the one-way missions of the cruise missiles, the UAVs would conduct their overflights, then return to a base for a landing.
In the past several years there has been considerable debate about combining the two roles to create an Unmanned
One of the biggest leaps of faith requirements for a UCAV is not technological but conceptual. There is a tendency to think of a UCAV as an unmanned F-16 or B-2. It is not. A UCAV is a unique concept, with its own specific, abilities. Some designs can fly at high altitudes and remain on station for a day or more over enemy territory, all without being detected by an enemy's air defenses. Any military role for a UCAV should capitalize on such capabilities, rather than trying to simply duplicate what manned aircraft can already do.
One operating concept for a UCAV could be 'air occupation.' A high-altitude, long-endurance stealthy UCAV could be fitted with long-range air-to-air missiles.
It would then patrol an area that would allow its missiles to cover a number of enemy airfields. A single UCAV could 'occupy' an area of several thousand square miles. Any enemy aircraft attempting to take off within this occupied zone could be destroyed by the UCAV's missiles as soon as the planes left the ground. Other possible air occupation missions include suppression of air defenses, destruction of ballistic missiles as they are launched,
