D-21 unmanned reconnaissance drone is a high-altitude, high-speed drone developed by Lockheed in the 1960s based on A-12/SR-71 technology. It has been kept in a state of high security for a long time, and the details were only revealed after the Cold War. Make it public. The aircraft first flew in 1964, entered service in 1969, and retired in 1971. It was the most mysterious reconnaissance aircraft during the Cold War, and even more mysterious than the A-12/SR-71 Blackbird high-altitude high-speed reconnaissance aircraft. The
D-21 high-altitude, high-speed UAV withdrew from the stage of history after only four actual combat attacks. Moreover, these four attacks were all directed at the Lop Nur nuclear test site in China. From November 1969 to March 1971, the D-21 UAV carried out four actual combat attacks, all directed at the Lop Nur test site in China, but all four strikes Was defeated. In the first three times, intelligence photos were successfully taken, but all recovered failed. In the fourth time, they disappeared after entering Chinese airspace.
During China's air defense operations in the 1960s and 1970s, the People's Liberation Army shot down U-2 high-altitude reconnaissance aircraft and Huobee unmanned reconnaissance aircraft. But another more advanced and mysterious US military hypersonic reconnaissance plane also secretly entered China, but there are few records in general historical materials.
On March 20, 1971, a mysterious aircraft crashed in the forest of Xishuangbanna, Yunnan Province, China. Based on the flight performance, Chinese searchers thought it was a US military SR-71 high-speed reconnaissance aircraft. At the same time, the United States is also very concerned about the fate of this aircraft, but has never figured out how it disappeared, thinking it was shot down by our country’s new air defense weapons. After finding the wreckage of the aircraft, relevant scientific and technical personnel of our country have basically understood the characteristics and performance of this new aircraft. It turned out that the United States used a B-52 aircraft to fly from the mainland to the South China Sea and dropped a new high altitude three. The top-secret unmanned reconnaissance aircraft at the speed of doublesonic invaded my country's airspace. The aircraft landed on the Leizhou Peninsula and crashed due to malfunction after making a large circle around the border of China. After
found the wreckage of the aircraft, my country has never released any official news. The United States did not recognize this type of D-21 in its publications until after 1977, and published a lot of relevant information in subsequent years. In August 2010, 39 years later, my country exhibited the remains of the D-21 drone to the public for the first time at the Xiaotangshan Aviation Museum in Beijing. This was the last D-21 drone that disappeared in 1971. The
D-21 high-altitude, high-speed UAV first adopted the world's leading ramjet at the time, with a speed of 3560 km/h and a ceiling of 29,000 meters. In the early 1970s, including the United States itself, no anti-aircraft weapon could theoretically shoot down the aircraft. The
D-21 drone has a total length of about 12.8 meters, a wingspan of 5.79 meters, a height of 2.14 meters, and a take-off weight of 5 tons. It uses a RJ43-MA-20S4 ramjet engine with a maximum speed of Mach 3.35, a maximum flight height of 29,000 meters, and a maximum range. 5550 kilometers.
