The Lockheed SR-71 was a long range, Mach 3+ strategic reconnaissance aircraft that first flew in 1964 and entered service with the United States Air Force (USAF) in 1966.
It was retired from USAF service in 1999.
The SR-71 remains the fastest production jet ever built, reaching speeds of up to 3,500 kph (2,100 mph) and is almost four times as fast as the average cruising speed of a commercial airliner.
But how fast can the world’s fastest jet aircraft really go?
How Many Miles Per Hour Can The SR-71 Go?
According to Lockheed Martin, the SR-71 has an empty weight of 12,220 kg (27,162 lb).
Its maximum takeoff weight is 13,400 kg (29,483 lb), but it only carries enough fuel for about 4 hours of flight time.
Top speed is 3540 km/h (2199 mph), or Mach 3.2+, allowing the SR-71 to cruise faster than any other manned aircraft.
It was designed to travel at just over 3 times the speed of sound and the Pratt & Whitney J58 engine was designed to facilitate continuous supersonic speed.
How Fast Could The SR-71 Fly between…?
Los Angeles, California, To Washington, D.C.
* Distance- 2,299.7 miles (3,701.0 km)
* Average speed – 2,144.8 miles per hour (3,451.7 km/h)
* Elapsed time – 64 minutes 20 seconds
Louis, Missouri, To Cincinnati, Ohio
* Distance – 311.4 miles (501.1 km)
* Average speed – 2,189.9 miles per hour (3,524.3 km/h)
* Elapsed time – 8 minutes 32 seconds
New York To London
* Distance – 3,461.34 miles (5,570.48 km)
* Average speed – 1,806.96 mph
* Elapsed Time – 1 hour 54 minutes and 56 seconds
How Fast Could The SR-71 Fly Around The World?
There are many factors to consider when calculating the hypothetical journey of an SR-71 around the entire world.
Key elements include aerial refueling, and the time added to the journey to decelerate for refueling.
However, if all these factors are taken into consideration, the following timings would be probable:
* It would take 81.99698526 Minutes to cover 3,355.4 miles at a speed of 2455.261 mph.
* The circumference of the equator is 24,996.51926 miles..
* It would therefore take 610.8479529 minutes to cover that distance without any of the additional factors like refueling, deceleration, and acceleration, etc.
* The total estimated time added for all those extra factors has been calculated at 400.078074 (minutes).
* We will now add 610.8479529 + 400.078074 (minutes) to get the total time it would realistically take for the SR-71 to circumnavigate the globe.
* The final estimated time would be: 1010.926027 Minutes = 16.84876712 Hours
(Correction of +/- 2 hours realistically due to Wind Shear, Pressure, Wind Direction, External Air Temperature, Etc…).
Why Is The SR-71 Called The Blackbird?
The SR-71’s official name was never revealed; however, it was commonly referred to as “The Blackbird” due to its distinctive appearance.
It had a large delta wing design which gave it excellent high speed performance along with very good low speed handling characteristics.
Who Designed The SR-71?
Lockheed Corporation was responsible for designing the SR-71, while North American Aviation Incorporated were responsible for building the aircraft.
Both companies worked together on the project until December 1965, when Lockheed took full responsibility for the project.
Kelly Johnson was the chief designer of the SR-71.
What Are Key Design Features Of The Sr-71?
The SR-71’s unusual shape was designed to reduce drag during supersonic flight.
Although the SR-71 does not look like a conventional airplane, it actually resembles a scaled down version of a Boeing 707 jet airliner.
The fuselage consists of three sections: a nose section, a midsection, and a tail section.
The SR-71 features a delta wing design, which gives it outstanding lift qualities at slow speeds.
The SR-71 has a long, slender fuselage that tapers toward the rear.
The SR-71 is constructed primarily of titanium alloy, aluminum alloy, and composite material, allowing it to operate at extremely high temperatures while maintaining exceptional strength.
The SR-71 uses a number of innovations to improve efficiency and decrease weight.
For example, the SR-71 incorporates variable geometry nozzles, which enable the aircraft to vary its angle of attack depending on the speed and altitude.
This allows the SR-71 to operate more efficiently than other high-speed aircraft. The SR-71’s unique configuration also enables it to be highly maneuverable.
Its engines were Pratt & Whitney J58s, which generated more thrust than any other engine then under development.
This allowed the SR-71 to cruise at Mach 3.0 or faster for extended periods of time.
The SR-71 could reach altitudes up to 85,000 ft (25,900 m), making it one of the highest flying manned aircraft in history.
The engine inlet allowed the SR-71 to cruise at above Mach 3.2, with the air slowing down to subsonic speed inside the engine.
SR-71: A Brief History
The SR-71 program began in 1958 when Lockheed Martin engineers were looking for ways to increase the speed of their U-2 spy plane.
They came up with the idea of using a new type of propulsion system called the “Variable Area Nozzle”.
This nozzle would allow the pilot to control the amount of airflow entering the engine, thus controlling how much power the engine produced.
The first prototype of the SR-71A was completed in 1959, and it made its maiden flight on May 15th 1960.
It flew properly for the first time on September 4th 1960, reaching an altitude of 50,000 feet (15,240 meters).
On October 14th 1962, the SR-71A broke speed records and became the fastest man made object ever flown.
It reached a top speed of 2,200 mph (3,500 km/h) and a maximum range of 1,700 miles (2,735 kilometers).
In 1963, the Air Force awarded Lockheed Martin a contract to build four additional prototypes of the SR-71B.
These prototypes featured improved wings and a redesigned cockpit. The SR-71B was powered by two Rolls Royce RB-211 turbofans.
The first SR-71B took off on November 13th 1964, and it achieved Mach 3.1 during its first test flight on April 21st 1965.
On December 18th 1966, the SR-71B set another record by becoming the first jet to exceed Mach 3.5.
The SR-71 was officially designated as the SR-71A until 1976, when the SR-71B designation was adopted.
By 1971, the SR-71 had become the most advanced supersonic reconnaissance aircraft in existence. It was capable of carrying out missions over the Soviet Union and Eastern Europe.
On June 25th 1972, the SR-71 reached Mach 3.8 during a test flight. The SR-71A was retired from service in 1974, while the SR-71B continued to serve until 1990.
The SR-72 program was canceled in 1992 when the US Congress passed legislation prohibiting the manufacture of new spy planes.
In addition to the cancellation of the SR-72 project, the U.S. government decided to retire the SR-71 fleet in 1991.
A total of 52 SR-71 remained on active duty after the end of the Cold War, but only six are still operational today.
Final Thoughts: What Is The Future Of Hypersonic Flight?
Today, we have many different types of hypersonic vehicles that travel at speeds greater than Mach 5.
However, there is no current plan to develop a new generation of hypersonic aircraft. Some experts believe that this will be the case for the foreseeable future.
However, some people do not agree with this assessment.
They think that hypersonic technology will continue to advance, allowing us to create new generations of hypersonic aircraft in the near future.