The Dream of Supersonic Passenger Plane

American startup Hermeus will build a passenger plane up to 5 times the speed of sound, which can fly from New York to London in 90 minutes. Since the Concorde retired nearly 20 years ago, people’s interest in supersonic travel has been accelerating, and several super-high-speed aircraft are under development. Airlines also seem to be very interested. United Airlines has promised to provide supersonic routes as early as 2029.

Hermeus is a start-up company headquartered in Atlanta, USA, whose goal is to develop a hypersonic aircraft, and already testing a new engine designed for the small unmanned hypersonic aircraft currently manufactured by Hermeus for the U.S. Air Force, but when the size is enlarged, it will be able to power passenger aircraft.

According to Hermeus CEO AJ Piplica said: "To help us determine the size of the aircraft, we established a basic business model for an airline. We focused on business class and first class passengers, and then considered some parameters, such as flight speed and the operating costs, the we are developng a passenger plane that can accommodate 20 people."

Furthermore, he also stated that, "This is not far from the capacity of a large business jet, which means there is only one type of space. We hope it will be profitable at today's business class price." but it should be noted that it is difficult to estimate how much people are willing to pay for a five-times increase in flight speed, because "you can't really answer this question until there is a product there, so you can have real data."

The aircraft has a range of approximately 4,000 nautical miles, which is sufficient for trans-Atlantic routes such as New York to Paris, but not suitable for trans-Pacific routes such as Los Angeles to Tokyo, which require a stopover. Due to noise regulations, a land route from New York to Los Angeles is also impossible breaking the sound barrier is accompanied by a loud roar, which usually occur on the water.

To understand how bold the idea of ​​a Mach 5 passenger plane is, it is useful to look at past flight speed records. The fastest flight speed of any aircraft equipped with an engine is Mach 9.6 (approximately 6,800 mph), which is a record set by NASA X-43A in 2004-this is an unmanned aircraft about 12 feet long .

Since that flight lasted only a few seconds, the record of the longest continuous flight exceeding Mach 5 belongs to the Boeing X-51, another unmanned experimental aircraft, which operated at Mach 5.1 (approximately 3,400 mph) in 2013. Flew at speed for more than 3 minutes. Both aircraft must be launched from a high altitude by a B-52 bomber and then accelerated by a rocket, which highlights the complexity of this type of high-speed flight.

For manned aircraft, the current absolute speed record is Mach 6.7 (4,520 mph), set by the X-15 in 1967. It is basically a rocket with a seat, designed to achieve records, and must also be launched from high altitude by the B-52.

For air-breathing aircraft capable of taking off and landing on their own, powered by jet engines rather than rockets, the speed record is "only" Mach 3.3 (approximately 2,200 mph), used by the SR-71 Blackbird military aircraft was realized in 1976.

The Concorde is one of only two commercial supersonic passenger aircraft with a top speed of Mach 2.04 (1,350 mph). Therefore, the proposed Hermeus passenger aircraft will greatly exceed the current record for the fastest aspirating aircraft, and by flying at a speed of Mach 5 for a longer period of time, it will surpass the current achievements in the field of unmanned experimental aircraft. Of course, other aircraft may break these records before Hermeus in the future).