D-21 - is the result of "Lockheed" development company based on supersonic aircraft A-12. This idea arose when 1 May 60-year was hit by an American reconnaissance U-2B Soviet missile near Sverdlovsk region. Then the US government banned flights by manned reconnaissance over the territory of the USSR. The Central Intelligence Agency had to ignore in these innovations and adopt new measures for the establishment of a long-range unmanned.

Thus, the company "Lockheed" began designing experimental apparatus X-7A 1, X-7A-2 and X-7A-3. Studies have shown that the best motor for driving the UAV will ramjet RJ43-MA-11, developed by "Marquardt". As the power plant was originally developed for the cruise missile "Bomark" in terms of its use of drones to the designers had to make some improvements.

In the first place it completely changed the device, stabilizing the flame, and mounted a new system and re-start the cooling nozzle. Thus, increased time on the half hour. Upgraded engine renamed XRJ43-MA20S-4. First, the new device was planned for a single use, which held a series of works on reducing the weight and cost. But there was a question about the loss of expensive navigation systems and photographic equipment. For this construction set parachute glider container.

The first life-size mock-up was prepared in December 62-year. At the same time, the development company specialists conducted radar tests, which demonstrated low visibility drone. Optimal performance revealed in tests in the wind tunnel. But the CIA leadership is not particularly complain about the results of this work. The new car was designated as Q-12.

But the new UAV strongly interested in the Air Force, which has already started to consider it as a cruise missile or reconnaissance. A little later, the representatives of the CIA and the Air Force signed a contract for co-financing of the UAV. And in March 1963, the company "Lockheed" leadership received an official letter from the Central Intelligence Agency to conclude a contract for the production of UAVs already renamed D-21.

At the same time before designers created a new problem with the separation of D-21 from its carrier A-12. In October 63-year project D-21A was completed with a new carrier M-21. New bundle was given a new designation -Tagboard.

The developed design was made of steel and titanium, and only a small part - from composite radio-absorbing materials. The container, in which the reconnaissance equipment was contained, and the guidance system were located in a compartment with a length of 1,9 m. An inertial navigation system INS, an automatic control system AFCS, an air parameters calculator ADC were placed in it. Normal operation in the container was provided by the air-cooling unit of the avionics. Before the flight, the number of autonomous flight was entered in the calculator. The initial concept of the project included disconnecting the device from the carrier and further flying in an autonomous mode according to a pre-programmed program. The flight ended over the ocean, where a container with intelligence was dropped. The UAV itself detonated at the request of a barometric sensor. The container descended from an altitude of 4,5 km on a parachute, hanging on an 20-meter cable with a "cat's mustache", which ensured reliable engagement of the MARS system. This system was equipped with a rescue and search aircraft JC-130B. If the container fell into the water, its recovery was carried out on a specially equipped vessel.

Pilon UAV equipped with a pneumatic and mechanical locks and a device for supplying fuel, which consisted of two pipelines. One provided a cooling circulation system, skin, and the other ran the scout fuel tanks.

The UAV control operator was in the second cockpit of the carrier aircraft. His place was equipped with a periscope, with which he observed the UAV. 7 D-21A units were prepared for the first flight tests. The tests did not particularly satisfy the representatives of the Air Force and the CIA, so the designers developed an additional Senior Bowl program, which was based on the concept of hanging two UAVs on a B-52H aircraft. The drones have also been modified and renamed D-21V. The D-21B was first launched from a bomber at the end of September 1967. But the first test ended negatively, because when disconnecting the BA touched the pylon and fell. In addition, several more exercises were carried out, but none of them ended in success.

The tests continued for a long time, so in 1971, the last UAV launch took place to gather intelligence on China. In general, the test in combat conditions was successful, but on the way back, the drone was lost. The military suggested that he was hit by air defense weapons. In July, the program ceased to exist due to the restoration of diplomatic relations between the United States and China. The need for such a device has disappeared. Attempts were made to restore the operation of the UAV for the purpose of NASA, but with careful study, the management abandoned this undertaking. 

D-21. Characteristics:

Modification   D-21
Wingspan, m   5.87
Aircraft Length m   12.33
Height, m   2.19
Weight, kg   4990
engine's type   1 ramjet Marquardt RJ43-MA-11
Thrust, kgf   X 1 680
The maximum speed M   3.30
Practical range, km   4830
Practical ceiling, m   29000


Other UAVs