In February 1986, D-21B Article 517 finally came home. After the guidance system malfunctioned on the first overflight, it had kept going and reached Siberia before self-destructing. The shattered debris rained down from the sky. One of the pieces, a panel from the engine mount, was found by a shepherd, who turned it over to Soviet authorities. Seventeen years after the November morning it was launched, a CIA official walked into Ben Rich's office with the panel. Rich, now head of the Skunk Works after Kelly Johnson's retirement, asked where he had gotten it. The CIA official laughed and said, "Believe it or not, I got it as a Christmas gift from a Soviet KGB agent." The panel, composed of radar-absorbing material, looked as if it had just been made.[338]
As they talked, another Dark Eagle was being built in the same hangar that had seen production of the D-21s. It did not have the thundering speed of the D-21; in fact, this new plane was a subsonic attack aircraft. Unlike the sleek, manta ray shape of the D-21, the new Dark Eagle was angular. It had a form that was a violation of every aerodynamic principle built into airplanes since the Wright Brothers. This strange shape, crafted with the utmost care, had only one virtue.
It was invisible.
CHAPTER 7
The Dark Eagles of Dreamland
The Have Blue Stealth Aircraft
I conceal my tracks so that none can discern them; I keep silence so that none can hear me.
A common thread running through the history of the postwar Black airplanes was the quest for a reduced radar cross section. It was hoped that the U-2 would fly so high it would be difficult to pick up on radar. Tests over the United States seemed to justify this hope, but once overflights began, the Soviets had no major difficulties tracking it. Attempts were made to reduce the U-2s' detectability, but these proved ineffective.
Based on this experience, Kelly Johnson realized the A-12 would have to be designed from the start for a reduced radar cross section. The important word was reduced—the North Vietnamese and Chinese were able to detect the A-12s. Taken together, the A-12s' speed, height, and reduced radar return made them unstoppable.
With the Ryan drones, both approaches were taken. The Model 147 Lightning Bug drones were modified with radar-absorbing blankets. This made the former target drones difficult to shoot down, as the Chinese and North Vietnamese soon learned. With the advanced Model 154, a reduced radar cross section was built in.
In all these cases, however, the reduced radar cross section was only one of the design considerations. The maximum possible altitude was the driving requirement in the design of the Black reconnaissance airplanes.
But by the early 1970s, a reduced radar cross section became the dominant consideration in the design of new aircraft. This became known as "stealth."
The first attempt to build an "invisible" airplane was made in 1912.
Petrocz von Petroczy, an officer with the Austro-Hungarian air service, covered a Taube with clear sheets of a celluloid material called Emaillit.
The theory was that a transparent covering would make the plane harder to see and hit with ground fire compared to a fabric-covered plane silhouetted against the sky. The Taube was test flown in May and June 1912.
Flight magazine reported that the plane was "unable to be located by those present on the ground when flying at an altitude of between 900 and 1,200 feet… [At 700 feet] only the framework is dimly visible and this and the outline of the motor and pilot and passenger present so small an area for rifle or gun fire, that… accurate aiming at such surfaces becomes nearly impossible."
It was the Germans who soon took the lead. An engineer named Anton Knubel built two monoplanes with clear coverings in 1913-14. The second of the planes had its framework painted a blue gray color to make it even harder to see against the sky. In August 1914, World War I started. In 1915, Knubel built a biplane to test its military applications. Unfortunately, Knubel was killed in a crash of the plane on September 8, 1915.
The idea was seen as having promise, and three Fokker E III fighters were delivered in the summer of 1916, covered with Cellon. Unlike celluloid, it did not burn or shatter. Cellon had found wide use in the automotive industry as a glass substitute. Cellon was soaked in water to expand the sheets. It was then attached to the plane's framework and allowed to dry to a taut finish. The material was called D-Bespannung (Durchsichtige Bespannung or "transparent material under tension").
The trio of E III fighters appear to have seen limited combat. On July 9, 1916, the No. 16 Squadron of the British Royal Flying Corps reported that "a transparent German aeroplane marked with red crosses was pursued by French machines in the Somme area." Several more German aircraft were tested with the Cellon coating. These included four observation-light bombers: an Albatros B II, an Aviatik B, an Aviatik C I, and a Rumpler C I. Two heavy bombers, a VGO I and R I, had their tails and rear fuselages covered with the material.
Very soon, however, it was apparent this first attempt at a stealth airplane was a failure. A report dated July 11, 1916, states: "In clear weather, the aircraft is more difficult to spot, but in cloudy weather, it appears just as dark as other aircraft. In sunshine, the pilot and observer are unpleasantly blinded by the reflections." The major problem was the Cellon itself: "During longer periods of rain or damp weather… the covering becomes so loose that it would be better not to fly such aircraft… The covering itself is strong, but should a shrapnel go through the wing, the whole sheet would tear to pieces."
It was far more effective simply to paint the aircraft in camouflage colors. This could not make the plane invisible, as the German planes attempted to be, but would make the plane less visible.[339]
With the invention of radar in the mid-1930s, a new approach was needed. A variety of countermeasures emerged during World War II. The simplest means was strips of aluminum. Called "chaff" in the United States or "window" in England, the strips would be released from a plane. They would reflect the radar signals and produce false echoes, which would hide the plane. A more active method was to interfere with the radar. Called "noise jamming," the target plane transmitted signals on the same frequency as the radar. As the echo from a plane was a tiny fraction of the radar's original signal strength, it was possible for the plane to drown out the echo, making it impossible to detect the target plane.
With development of jet bombers like the B-47 in the late 1940s, it was thought that they would fly too high and too fast to be detected. This soon proved false, and development of electronic countermeasures (ECM) continued.[340]
During the Cold War, both the ECM and the tactics of its use grew more sophisticated. The first step was to avoid the radar entirely. The Soviet Union was vast, and many areas had little or no radar coverage. The bomber's route would take it through these gaps in the radar. The plane would not transmit any jamming signals, as this would only advertise the plane's presence. As the bomber neared the target, the number of radars would increase, and it would no longer be possible to avoid them. The bomber would then start to drop chaff and jam the radars. A more subtle approach was to transmit carefully timed signals, which made the plane appear farther from the radars, or at a different bearing. This is referred to as "deception jamming." As a last resort, the air defense centers, radars, and SAM sites would be bombed.
338
Rich and Janos,
The 123 DBR first entered service in the late 1960s and was phased out in the late 1970s/early 1980s. As with the D-21, it would remain Black for a decade. It was not until early 1994 that photos of the 123 DBR were released by the Russians.
339
Peter M. Grosz, "So, What's New about
340
Alfred Price,