It is the representative of flying height and speed.

It is the representative of flying height and speed.

SR-7 1 Blackbird was developed in February 1963, and the test flight of 1964 began in February. 1October 1966 was put into use, and all were retired in February 1990. SR-7 1 fuselage is 93% titanium alloy, aerodynamic shape is delta wing and double vertical tail, and the engine is arranged on the wing. SR-7 1 has three modifications: A type and strategic reconnaissance type, with a total of 25 aircraft produced; Type b, coach type, a total of 2 vehicles; Type c, a coach type modified from type a.

The captain is 32.74 meters, the aircraft height is 5.64 meters, the maximum takeoff weight is 77. 1 1 ton, the maximum flight speed is 3.2 times the speed of sound, the reconnaissance altitude is 24,000 meters, the operational radius is 1930 kilometers, and the range is 4,800 kilometers. Airborne equipment includes astronomical navigation equipment, laser ranging equipment, electronic countermeasures equipment, synthetic aperture radar, high-resolution camera, infrared and electronic detectors, etc.

There are two members on SR-7 1: the pilot and the system operator. The cockpit is connected in series. Because the flight altitude and speed of SR-7 1 are beyond the human body's tolerance, the two members must wear fully sealed flight suits and look like astronauts.

The fuselage of SR-7 1 is mostly titanium, which was obtained from the Soviet Union at the peak of the Cold War. Lockheed used various feasible camouflage methods to prevent the Soviet government from knowing the purpose of this titanium. In order to reduce the cost, they used titanium alloy which can be softened at lower temperature and processed more easily. The finished aircraft will be painted dark blue (close to black) to enhance the cooling and camouflage effect of high-altitude thermal radiation.

In order to withstand the high temperature caused by air friction during sustained supersonic flight, Blackbird needs to adopt a series of specially developed new materials, including high-temperature resistant fuel, sealant, lubricating oil and other components. The study of titanium skin shows that this material will gradually strengthen in continuous intense heating like annealing.

The main part of the skin inside the main wing is actually wrinkled. Thermal expansion will tear or curl the smooth skin, wrinkle the skin, and make it stretch in the vertical direction to avoid excessive stress and enhance the longitudinal strength. However, aerodynamic experts accused engineers of trying to fly a 1920s Ford three-engine plane (famous for its wrinkled aluminum skin) to Mach 3. Some SR-7 1 have a red warning strip near the center of the fuselage to prevent maintenance personnel from accidentally damaging the skin, because the skin here is very thin and fragile, and there is no structural beam under a large area to provide additional support.

SR-7 1 is designed to have a very small radar reflection cross section, which is an early stealth design. However, this does not include high-temperature engine exhaust. So ironically, SR-7 1 is one of the biggest targets on the long-range radar of the Federal Aviation Administration, which can be tracked from hundreds of miles away. Even though a lot of stealth technology is used, it actually has no stealth function because of its huge infrared characteristics during high-speed flight. However, depending on its high speed, SR-7 1 successfully got rid of thousands of attacks against her, most of which came from aircraft and air-to-air missiles of the former Soviet Union.

The main mission loads of SR-7 1 include advanced electronic and optical reconnaissance equipment such as reconnaissance camera, infrared and electronic detector, AN/APQ-73 synthetic aperture side-looking radar, but they are all in absolute secrecy. Through the analysis of its flight speed and optical camera, it can complete the optical photography reconnaissance task with an area of 324,000 square kilometers in 1 hour. The performance of its optical lens is beyond ordinary imagination, but the resolution is highly confidential. In order to avoid the error caused by the forward flight of the aircraft, the reconnaissance cameras are all installed on the guide rails and move backwards when shooting, so that the cameras are stationary relative to the ground.

JP-7 was originally developed for A- 12 and has a very high flash point to avoid spontaneous combustion at high temperature. JP-7 contains fluorocarbon to increase lubricity, oxidant to make it easy to burn, and even cesium formula to disguise the radar signal of exhaust gas. This also makes JP-7 more expensive than scotch whisky, and the fuel cost for running SR-7 1 hour is 24,000 to 27,000 dollars. In contrast, U-2 only needs one third of it, but its flying speed is only about one quarter of that of SR-7 1, and it can carry much less reconnaissance equipment.

SR-7 1 is the first practical jet plane to successfully break through the "thermal barrier". "Thermal barrier" refers to the problem that when the aircraft speed reaches a certain level, friction with air will generate a lot of heat, thus threatening the structural safety of the aircraft. Therefore, titanium alloy with light weight and high strength is used as the structural material for the fuselage; The wing and other important parts are designed to adapt to thermal expansion, because when SR-7 1 flies at high speed, the fuselage length will be extended by more than 30 cm due to thermal expansion; The oil tank pipeline is ingeniously designed, adopting an elastic box, and using the oil flow belt to increase the heat at high temperature.

Although many measures have been taken, the oil tank will still leak to some extent after SR-7 1 landed, due to the thermal expansion and cold contraction of the engine block. In fact, SR-7 1 usually only needs a small amount of fuel when taking off, and refuels in the air after climbing to cruising altitude.

SR-7 1 is the fastest manned aircraft in the world, and it holds two records:1On July 28th, 976, a SR-7 1 set a speed record of 3,529.56 kilometers per hour and an altitude record of 25,929 meters (only the MIG -25 flying fox interceptor of the former Soviet Union was at 6,549 meters). It can scan the surface at a height of about 24 kilometers and a speed of about 72 kilometers per second.

When SR-7 1 retired in 1990, one of them flew from the 42nd factory of the US Air Force in Palm Valley, California to the National Air and Space Museum in Shantilly, Virginia, with an average speed of 3418km, and the whole journey took only 68 minutes. SR-7 1 still holds the record from new york to London set on September 1974: 1 hour 54 minutes 56.4 seconds. (Concorde takes 3 hours and 20 minutes to fly the same distance, while Boeing 747, the fastest subsonic passenger plane, takes 7 hours. )

The high operating cost of SR-7 1 is one of the main reasons for its retirement, although even some members of Congress think that it is still a strategic reconnaissance plane that cannot be replaced by other aircraft. In the mission preparation request report submitted by the US Air Force, it is proposed that two SR-7 1A will be re-commissioned for 30 days every month, at a monthly cost of $39 million.