The Speed Champion of the Skies: The NASA X-43

When it comes to identifying the fastest fighter jet, you can either limit the comparison to those currently in service or extend it to every jet that has ever graced the skies. We've opted for the broader perspective, considering all the jets that have ever made their mark in aviation history.

Fighter jets have always been at the cutting edge of aviation, constantly pushing the limits of altitude and performance. Unlike commercial airliners, they prioritize speed and agility, with many also equipped with stealth features, the capability to fire air-to-air missiles, and other remarkable attributes.

Given the advanced technology required for these military aircraft — with the safety of pilots often on the line — each one represents a significant milestone in engineering. They lay the foundation for the next generation of fighter jets, which will be even faster, more powerful, and better equipped. In honor of this spirit of innovation, here are seven of the fastest jets in aviation history.

1. NASA X-43

The X-43, an experimental marvel, holds the title of not just the fastest fighter jet but the fastest aircraft ever created, reaching an astonishing top speed of Mach 9.6.

As part of the $230 million Hyper-X initiative, the National Aeronautics and Space Administration (NASA) developed the X-43 to push the boundaries of hypersonic flight. In doing so, NASA broke speed records and advanced the frontiers of aerospace technology.

Technical Setbacks

Due to the X-43's unique design, NASA had to release it from a B-52 bomber to get it airborne. Once in the air, however, the flights were remarkably brief.

NASA lost the first X-43 in 2001 when it malfunctioned during testing. By 2004, the two remaining jets each flew for only 10 seconds, reaching Mach 6.8 and Mach 9.6 respectively, before crashing into the ocean after gliding for 10 minutes.

Is it Technically Disqualified?

Some critics argue that the X-43 shouldn't be considered a fighter jet, as it was an experimental, unmanned vehicle built for speed rather than for combat and dogfighting.

However, given the federal support behind the project and its military implications, others believe this supersonic aircraft deserves to be recognized as the fastest fighter jet ever.

2. North American X-15

The X-15, a collaborative effort between NASA and the United States Air Force (USAF), was a revolutionary aircraft that helped pave the way for the X-43. With the ability to reach speeds exceeding Mach 6, this rocket-powered jet was developed during the 1950s and 1960s.

The Fastest Flight in a Manned Aircraft

Similar to the X-43, the X-15 was carried into the sky by a B-52, but unlike its successor, it was a manned vehicle. In 1967, pilot Pete Knight made history by flying at Mach 6.72—6.72 times the speed of sound—marking the fastest recorded flight in a manned aircraft.

A Well-Deserved Retirement

The high-performance X-15 completed 199 test flights before being retired by NASA and the USAF in 1968. A famous USAF photograph from the 1960s shows an X-15 soaring over Edwards Air Force Base during one of its supersonic flights.

3. Lockheed SR-71 Blackbird

No conversation about fast fighter jets would be complete without the mention of the iconic SR-71 Blackbird.

Developed during the Cold War, this high-performance reconnaissance aircraft could reach a top speed of Mach 3.30, soaring more than 16 miles (85,000 feet or 25,908 meters) above the Earth. Due to the risks of rapid cabin pressure loss, the Blackbird's crew wore specialized pressure suits akin to those used by astronauts.

The U.S. military sought a fighter jet capable of evading interceptors and surface-to-air missile systems. The Blackbird delivered, providing the speed needed to stay ahead of threats.

With its sleek, all-black design and unparalleled speed, the SR-71 earned a reputation as the pinnacle of aerospace engineering and a symbol of America's air dominance.

4. Bell X-2 Starbuster

In the early era of supersonic flight, the Bell X-2 Starbuster emerged as a trailblazer, laying the groundwork for future aircraft such as the X-43 and X-15.

The X-2 was the result of a 1945 partnership between Bell Aircraft Corporation, the U.S. Air Force (USAF), and the National Advisory Committee for Aeronautics (NACA).

A Tale of Triumph and Tragedy

In 1956, Capt. Milburn G. "Mel" Apt made history by breaking the sound barrier and reaching Mach 3.20 in the X-2, becoming the first person to fly faster than Mach 3.

Tragically, after setting this remarkable speed record, the jet spiraled out of control. Although Apt ejected from the capsule he was piloting, he was unable to deploy his parachute before the capsule impacted the ground.

5. Lockheed YF-12

In the 1960s, the USAF initiated the development of the Lockheed YF-12 as a prototype interceptor, designed to fly at high altitudes while protecting military assets from enemy supersonic bombers.

Lockheed and the military built three YF-12 aircraft, with at least one achieving a maximum speed of Mach 3.20 during test flights.

Despite the impressive performance of the YF-12, the USAF eventually ran out of funding for the program, choosing to allocate resources elsewhere due to the ongoing Vietnam War. While it never entered full production, the YF-12's capabilities paved the way for the development of future high-speed military jets.

The last remaining aircraft is on exhibit at the National Museum of the United States Air Force, located in Ohio.

6. Mikoyan-Gurevich MiG-25 Foxbat

Developed during the Cold War by the Soviet Union, the MiG-25, or 'Foxbat' as it was known by NATO, became an iconic interceptor aircraft recognized for its astonishing speed. It could reach Mach 2.83 and entered service in 1970.

Intelligence Victory

In 1976, when Soviet pilot Victor Belenko defected to Japan, he flew a MiG-25, providing the U.S. military with a wealth of critical intelligence about the capabilities of the Foxbat.

The MiG-25 was developed by the Soviet Union as a countermeasure against high-altitude reconnaissance aircraft and bombers. Outfitted with sophisticated radar and four air-to-air missiles, the MiG-25 quickly became a major threat to Western air forces.

A Lasting Legacy

While the Soviet Union halted production of the MiG-25 years ago, its influence continued. Notably, Iraq used MiG-25s during both the Iran-Iraq War and the Persian Gulf War, showcasing the aircraft's enduring role in global conflicts.

7. Mikoyan-Gurevich MiG-31 Foxhound

Taking the legacy of the MiG-25 further, the MiG-31, or 'Foxhound,' was introduced as a more advanced interceptor capable of targeting high-speed threats. With a top speed of Mach 2.83, this fighter jet debuted in 1975 and remains in service with the Russian Air Force (VVS).

The MiG-31, with its iconic fighter jet design, stands as a powerful contender in aerial battles. While the pilot manages airspeed and altitude, the weapon system officer (WSO) is responsible for controlling the radar and launching weapons.

Compared to the MiG-25, the Foxhound boasts superior radar systems and advanced avionics, allowing it to achieve high speeds with remarkable stability at lower altitudes—something its predecessor struggled to achieve.