Supersonic Flight

This week we talk about Mach 1, the Bell X-1, and the Concorde.

We also discuss the X-59, the Tu-144, and Boom Supersonic.

Recommended Book: Red Team Blues by Cory Doctorow

Transcript

The term “supersonic,” when applied to speed, refers to something moving faster than the speed of sound—a speed that is shorthanded as Mach 1.

The precise Mach 1 speed of sound will be different depending on the nature of the medium through which an object is traveling. So if you’re moving at sea level versus up high in the air, in the stratosphere, the speed of sound will be different. Likewise if you’re moving through moist air versus dry air, or moving through water versus moving through syrup, different speed of sound, different Mach 1.

In general, though, to give a basic sense of how fast we’re talking here, if an object is moving at sea level through dry air at a temperature of 20 degrees celsius, which is 68 degrees fahrenheit, Mach 1 is about 768 miles per hour, which is about 1,126 feet per second, and 343.2 meters per second.

It’s fast! It’s very fast. Again, this is the speed at which sound moves. So if you surpass the speed of sound, if you go supersonic, you will arrive faster than the sound you make while moving.

Back in 1947, an experimental American plane called the Bell X-1 broke the sound barrier, surpassed Mach 1, reaching a speed of almost 1,000 miles per hour using a 6,000 pound thrust rocket propulsion system. A later version of the same rocket-powered plane, the Bell X-1A, which was basically the same vehicle, it just had more fuel capacity, allowing the rocket to burn longer, achieved 1,600 miles per hour in 1956.

Prior to that, in 1943, British began working on a secret experimental aircraft called the Miles M.52, intending to build a plane capable of traveling 1,000 mph. Interestingly, this project was apparently the result of the British wanting to keep up with a supposed already existing German aircraft capable of achieving that speed, though it’s now believed the intelligence that led the British to believe the Germans had a supersonic-capable plane was the result of a mistranslation—the Germans hit 1,000 km per hour, which is about 621 mph, and still subsonic.

Though apparently a success in terms of research and innovation, the Miles M.52 project was cancelled in 1946, due partly to budgetary concerns, and partly because the new government didn’t believe supersonic aircraft were practical, or maybe even feasible.

After the existence of this project was revealed to the public, however, criticism for the cancellation mounted, and the design was translated into new, unmanned scale-model experimental versions of the plane which achieved controlled Mach 1.38 supersonic speeds, and both the design and research from this program was shared with the American company, Bell, and all that knowledge informed the development of the aforementioned Bell X-1 supersonic plane.

Again, that successful Bell mission was flown in 1947, and in 1961, a Douglas jetliner, a commercial jet, broke the sound barrier during a controlled test dive, and that fed the development of an intended supersonic airliner in the US, though similar research being conducted elsewhere would bear more direct and immediate fruit.

In the Soviet Union, a supersonic jetliner called the Tupolev Tu-144 entered service in 1968, and a jetliner co-developed by the British and French, the Concorde, began construction in 1965, and tallied its first flight in March of 1969.

The Tu-144 was thus the world’s first commercial supersonic airliner, by a few months, and it also became the first commercial transport to exceed Mach 2, twice the speed of sound, in 1970.

The Tu-144 was plagued by reliability issues from the get-go, however, and while performing maneuvers at an air show in Paris in 1973, it disintegrated in midair, which—combined with its high operating costs reduced its long-term market viability, especially internationally. By the mid-1970s, it was primarily operating within the Soviet Union, and after a new variant of the jet crashed in 1978, the Tu-144 program was cancelled in 1983. Existing models continued to be use for niche purposes, like training space program pilots, and for a supersonic research program undertaken by NASA in the late-1990s, but the final Tu-144 flight was in mid-1999, and all surviving aircraft are now on display or in storage.

The Concorde has a similar history. Original forecasts for the supersonic airliner market were optimistic, and while the craft seemed to be generally more reliable and less issue-prone than the Tu-144, and it enjoyed a period of fanfare and promotion, as a sort of luxury experience for folks crossing the Atlantic in particular, cutting travel times in half, a major crash in mid-2000, which killed all 109 o