Commercial supersonic planes could come back to the skies
The speed of flying faster than that of sound can still be considered a futuristic concept for ordinary people; over 15 years have passed since commercial supersonic flight was completed. The planes involved in these flights, the 14 jets that collectively are known by the name of “the” Concorde, were in operation from 1976 until 2003. It flew three times more quickly than normal passenger planes, and the airlines that operated it could not make a profit from its flights.
The reason why the Concorde wasn’t profitable was, in reality, a consequence of its velocity. When the plane was speeding over its sound velocity – around 780 mph – it caused high-frequency shockwaves in the atmosphere, which were able to land on the earth with an incredibly loud and abrupt crash that was a sonic “boom.” It is such a frightening sound for those on land that U.S. Federal regulations prohibit all commercial aircraft from flying at speeds greater than sound speed on the ground.
The rules, as well as the quantity of fuel the plane could carry, restricted the Concorde to transatlantic flights. The plane’s operation was so costly that the cost of a one-way flight between London and New York could cost more than $5,000. Also, the Concorde often flew with only half its seats empty.
The most significant benefit of traveling supersonic is the reduced time of flight. A flight that takes three hours across the Atlantic can make an entire full-day journey possible to travel from the U.S. to London or Paris, which would save one whole work day. Being an aerospace engineer who studies advanced air vehicle technology, I am convinced that the latest advancements in technology, as well as new developments in commercial aviation, could allow supersonic flights to be economically viable. But the regulations need to be changed before people can fly across the sky quicker than the sound.
When a plane speeds up and reaches its maximum speed, it creates an air pressure front by pushing air forward of it. Once it has reached its speed, it releases pressure that traces behind the plane like a boat’s wake and creates a sonic sound wave. Chabacano/Wikimedia Commons, CC BY-SA
The boom is not over yet.
As an aircraft travels in the air, it produces pressure disturbance waves, which are able to travel the distance of sound. If the helicopter itself is traveling more quickly than the sound of it, these disturbances are compressed to create a more powerful disorder known as the shock wave. Shock wave patterns that surround supersonic aircraft were recently captured in NASA tests. When a supersonic airplane is flying overhead, a portion of the shock wave could hit the ground. This is referred to as a sonic boom that is felt by a thumping sound that is quite shocking.
Sound booms are very intense.
Commercial flights are controlled within the U.S. by the Federal Aviation Administration. To safeguard the public from the sonic booms that can occur, current FAA regulations prohibit flying on land commercial aircraft flying at speeds exceeding supersonic.
But, NASA is working to drastically reduce the sound boom of the “X-59” program. By ensuring the proper shape of the plane, the aim is to lessen the impact of shock waves and keep them from hitting the ground.
Flight demonstrations are scheduled to begin in 2021. The success of NASA’s plan could be the key to removing one obstacle to flying supersonic.