The 10 fastest aircraft ever made

North American X-15 - Mach 6.7+ (1959)

©USAF

The X-15 was built to research piloted hypersonic (speeds above Mach 1) flight within and outside the Earth’s atmosphere. Lessons from the X-15 contributed to the Mercury, Gemini, and Apollo piloted spaceflight programmes as well as the later Space Shuttle programme.

The X-15 did not take off from a runway but was instead launched from beneath the wing of a modified B-52 Stratofortress bomber NB-52. This saved fuel, something the rocket engine burnt at a prodigious rate. The X-15 was air-launched at about 45,000 and a speed of 500 mph. The rocket engine provided thrust for the 80 to 120 seconds. Three aircraft were built and flew a total of 199 flights. Flying above 80km altitude, the pilots met qualification as astronauts.

North American X-15 - Mach 6.7+ (1959)

©USAF

The record for the fastest speed for a crewed aircraft has stood for an astonishing 57 years. The North American X-15 was a research aircraft built to explore extremes of speed and altitude. The X-15 reached an astonishing 4,519mph

Heat resistance came from the use of heat-resistant nickel alloy (Inconel-X 750). Earlier flights used the XLR11 rocket engine which used ethyl alcohol and liquid oxygen. The majority of flights (175 of 199) used the XLR99 which employed anhydrous ammonia and liquid oxygen as propellant.

Lockheed A-12 ‘Cygnus’

©USAF

At 30 metres, the A-12 was very long for a single-seat aircraft. It was designed for prolonged flight at Mach 3, so required titanium in its construction to survive a skin temperature reaching between 300 and 400 degrees. Such high-speed flight was enough to lengthen the aircraft, and it would only contract again was cool.

Though its maximum speed is often stated as Mach 3.35, it is likely that the A-12 was capable of even faster speeds with Mach 3.6 very possible. It flew operational missions for a short time before being replaced by the twin-seat and considerably more capable SR-71 Blackbird.

Lockheed YF-12 - Mach 3.35 (1963)

©Alan Wilson

‘Project Oxcart’ was a highly classified project to develop a reconnaissance aircraft for the US, that thanks to high speed and altitude performance would be immune to enemy interception by either fighters or surface-to-air missiles. It would also pioneer the yet-to-be-named concept of radar stealth.

The two entries above are essentially the same aircraft, but the single-seat A-12 was the first family member. The A-12 was beyond state-of-the-art, with many technologies required to be invented to make it possible.

Lockheed YF-12 - Mach 3.35 (1963)

©USAF

Another issue was its use of special JP-7 fuel. This meant it could not be air refuelled by normal tanking aircraft and would have to rely on a special fleet of tankers of Boeing KC-135Qs. The SR-71 would require 56 KC-135Qs, a hugely expensive effort – a force of F-12s would have required far more.

It was clear that a slower more conventional aircraft with long-range missiles would be a far easier and more effective option and the exciting F-12 was cancelled. Though cancelled, much of the long-range missile and radar technology developed for the A-12 would go on to inform the later Grumman F-14 Tomcat.

Lockheed SR-71 Blackbird - Mach 3.3 (1964)

©USAF

Mach 3.3 is the traditional quoted top speed of the SR-71 but more recent articles have put it at Mach 3.5 (and in some cases Mach 3.75). We’ll stick to the quote given directly to us by a SR-71 pilot, which is that it was fully tested up to Mach 3.3 (though it is said to have been ground-tested to Mach 3.6)

The Lockheed SR-71 Blackbird supplied the US with vital intelligence for much of the Cold War, proving invulnerable to interception. It is the fastest crewed aircraft – and fastest jet – to ever see military service and retains a cult bewitched by the mystique of this charismatic futuristic aeroplane.

Mikoyan MiG-25 ‘Foxbat’ - Mach 3.2

©Alex Beltyukov

For most of its life, it was used in the interceptor and reconnaissance roles, and it was in the latter role that it was caught on Israeli radar flying at Mach 3.2. This was well above the recommended normal limits of Mach 2.83 and is said to have wrecked the engines.

In 1976 Soviet Air Force fighter pilot, Viktor Belenko, defected to Japan in a MiG-25. Before the aircraft was returned it was hurriedly assessed in detail by Western intelligence agencies. The MiG-25 had been much feared, but studying the aircraft revealed it had far lower tech than expected.

Bell X-2 Starbuster - Mach 3.196 (air-launched)

©NACA

To withstand the high skin temperatures the X-2 used stainless steel and K-monel (a copper-nickel alloy) in its construction. The X-2s were powered by a two-chamber Curtiss-Wright XLR25 throttleable liquid-fueled rocket engine. Once the rocket had used its fuel out the X-2 made an unpowered glide back to land.

Capt. Milburn G. “Mel” Apt became the first person fly faster than three times the speed of sound on Sept. 27 1956. He reached 2094 mph (Mach 3.196) in the Bell X-2, but tragedy soon followed. Apt performed a sharp turn, causing the aircraft to tumble uncontrollably. Though Apt escaped from the aircraft, he was killed as he hit the ground in the escape capsule.

North American XB-70 Valkyrie (1964) – Mach 3

©NASA

It was hoped that the bomber’s performance would render it invulnerable to manned interception, but it was soon clear that ever more potent surface-to-air missiles were a real threat. Intercontinental ballistic missiles were the future, but the XB-70 project had momentum.

It became a political ‘football’ kicked around by the most powerful men in America, including Richard Nixon, John F Kennedy and Robert McNamara, all adopting pro or anti positions as suited their needs. Kennedy was pro-B-70 in the 1960 election campaign but changed his mind. The aircraft was cancelled, but did perform some research work for NASA.

General Dynamics F-111 Aardvark – Mach 2.91+

©USAF

“What we had was a heat sensor on the windscreen. When the sensor got hot enough, it caused a caution light to illuminate…warning was that if the timer reached five minutes, the windscreen would melt. I think the fastest anyone ever claimed to have gotten was Mach 2.91 (3594 km/h). In any event, no one ever saw the jet stop accelerating—everyone decided to back off before testing the egg timer…”

Following this interview, other former F-111 aircrew came forward claiming even greater speeds achieved, some as high as Mach 3.2 (we’ll stick to Jim’s already high claim). The F-111 was capable of such speeds due to the extreme sweepback angle possible with its variable ‘swing-wings’, its jet air intake design, general slimness and the type of engine.

Mikoyan-Gurevich Ye-150 series – Mach 2.85

©Mike1979

The Ye-150 series were wildly-high-performance heavy interceptors. They could out-drag and out-climb any fighter in the world, and they also looked exceptionally mean. Despite taking its first flight as long ago as 1959, the Ye-150 could reach an astonishing Mach 2.65 (some sources claim even higher speeds of Mach 2.85, or 3030 km/h) and could ascend to altitudes above 69,000 feet (21,031m).

The series of four experimental fighter-prototypes was built in an effort to create a new, highly automated fighter to defend the Soviet Union against a proliferating Western threat (including supersonic bombers like the B-58, then in development). To catch and destroy these fast, high-flying intruders, the interceptor was to be automatically steered under the guidance of ground radars before engaging its own cutting-edge detection and weapons systems.

10: MiG-31 ‘Foxhound’ - 1900mph - Mach 2.83

The MiG-31 has two turbofan engines, which when deploying afterburner (fuel burnt towards the rear of the engine to increase thrust) have a combined thrust of 68,000 lb ft (equivalent to 304kN). The engine is the Soloviev D-30. The MiG-31 first flew in 1975 and entered service in 1981.

Other than the two ancient, and barely flyable, MiG-25s in Syria, the MiG-31 is the fastest (known) crewed aircraft flying anywhere in the world in 2024. Though capable of Mach 2.83, the MiG-31 is limited to Mach 1.5 in peacetime to preserve engine and airframe life