The world's fastest plane SR-71 is about to be revived?

The legendary SR-71 reconnaissance aircraft in the US will be recreated in a new supersonic version of SR-72, expected to operate from 2030.

The world's fastest plane is about to be revived?

Born in the pinnacle of cold war espionage operations, America's iconic SR-71 "Blackbird" is still the fastest military aircraft the world has ever known. It can fly so high and so fast that the Russian air defense forces are almost helpless to stop. But eventually, satellite and radar technology surpassed the reconnaissance capabilities of SR-71. In 1998, the US Air Force retired "Black Crow" .

Now, with the increasing threat in the region and the evolution of air-to-air missile technology, US engineers once again set a goal of building the fastest military aircraft in action. new generation crystal.

Concept about SR-72.

Design goals

This time, the product is expected to have the shape of an unmanned reconnaissance aircraft that can fly at a speed of 4,000 miles per hour (about 6,500 km / hour) with combat capability. Named SR-72 , it has the ability to evade enemy aircraft, take spy photos, attack targets at speeds of up to Mach 6 (about 5,800 km / h) - twice as fast as its predecessor SR. -71.

Airline engineers of Lockheed Martin and Aerojet Rocketdyne began designing SR-72 at Skunk Works in California for years. In order for the aircraft to become a reality, it requires a combined propulsion system. In addition to a conventional turbojet (turbojet) jet engine to fly to Mach 3, it will need a linear jet engine (ramjet / scramjet) to reach the remaining maximum speed.

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In addition, the fuselage will have to withstand the extremely high temperatures of the supersonic flight, because the air friction itself can also melt the steel. Iron bird bombs must also target from 80,000 feet (over 24km). Lockheed expects the SR-72 to be put to use in 2030. At that time, the machine's ability and speed will take it to any point in the world in just 1 hour.

Engine challenge

With the ramjet engine, the traditional compressor part was discarded. Instead the air is brought straight in and compressed when they are cornered into a diffuser. The diffuser simultaneously slows the airflow (opposite to the aircraft) to the low speed for easier burning. After that, the air and fuel were mixed into the combustion chamber and burned. Finally, a discharge nozzle accelerates the flow of hot air, increasing the volume of air to create a large thrust.

Meanwhile, the turbojet engine is used to get the plane from the runway up to a speed of about Mach 3. From Mach 4 will have to use a ramjet engine. To bridge the gap between these two types of engines, engineers developed a hybrid engine that could operate in three modes. Accordingly, from Mach 3 or below, the aircraft will use turbo mode; to reach Mach 5, the aircraft uses ramjet mode and above Mach 5 is the scramjet (supersonic combusting ramjet) mode.

Model on the computer of SR-72.

Material challenges

Aerodynamic friction at speeds exceeding Mach 5 will make the plane's surface heat up to a thousand degrees. At this level, the usual metal airframe will melt. So engineers are looking for new composite materials - high heat-resistant materials combining carbon, ceramic and metal are used on intercontinental ballistic missiles and space shuttle. All separators on the fuselage must be carefully sealed. Because of any leakage at supersonic speed, the temperature due to internal friction will cause the aircraft to explode. Space shuttle Columbia exploded for that reason.

In addition, the change between operating speed levels (subsonic, supersonic, and supersonic) creates a significant pressure on the entire fuselage. For example, when an aircraft starts to accelerate at subsonic stage, the propulsion point of the entire structure is behind the plane. But when the iron bird reached the supersonic level, stretching the outermost points of the fuselage caused the upper point to move forward. But the danger is that if the setpoint of the force coincides with the focus of the plane, it will cause the entire structure to be unbalanced in terms of motivation (if the force vector passes through the center, there is no moment). The constant change in the set point of the force required the structure of the aircraft to have tremendous resistance to keep them from being torn into the sky.

Combat ability

SR-71 "Black Crow" legend.

Lockheed described the SR-72 as an intelligence plane, spy, reconnaissance and attack. But its payload is still a secret. Shooting spies or bombing at Mach 6 will require sophisticated techniques. Only one shot or "miss" , the iron bird will have to fly hundreds of kilometers to get back to its old position. It also requires accurate ballistic calculations when cutting bombs from a height of 24km at a speed of nearly 6,000km / hour (or 1.67km / sec). Not to mention, with friction when traveling at such a high speed, the opening of the bomb cutting chamber also poses great challenges for engineers.

With all these difficulties and challenges, we cannot be sure whether Lockheed can successfully develop SR-72 before the time of 2030. Or SR-71 will continue to hold the world's fastest jet legend . More information is that only 32 SR-71s were produced, but 12 were damaged in the accident, all of which were not caused by the enemy.