By Yechezkal Freundlich, Senior Science and Technology Editor
The date is October 24, 2003, and people are bustling through Heathrow airport. A commotion begins by one of the terminals. People gather by the glass windows, parents and children, young and old, all waiting excitedly as they watch the British Airway’s final Concorde, the G-BOAG, successfully land after having gone supersonic more than 5,600 times, marking the end of a 27 year aviation lifespan.
From 1976 to 2003, western aviation lived in the future. The Concorden – a plane commercialized for civilian travel in January of 1976 – cruised at over 1,300 mph and reached max speed of mach 2. The Anglo-French machine was a joint development project by Sud Aviation and British Aircraft Corporation. Initially only flying from London to Paris, in late May of that year, the Concorde began transatlantic flights from London and Paris to Washington D.C. and later New York. The futuristic technology, flying faster than the rotation of the earth, could onboard passengers at breakfast time in London and have them arrive in New York well before breakfast Eastern Standard Time that same day, essentially time traveling. The now 7-hour flight from London to New York was done in less than half the time. Due to flying faster than the Earth’s rotation, when flying west from London to New York in the evening, from the perspective of the passengers onboard, the sun would appear to begin rising again shortly after reaching cruising speed.
The Concorde would only reach frightening speeds and break the sound barrier over the ocean to avoid scaring people. My father, who lived in England during the Concordes lifespan, described the landing in Heathrow airport as “a thunderous roar, sounding like an army jet. Heathrow airport had a viewing platform where you could go specifically to watch the Concorde take off and land.” For years, growing up with tales of this supersonic aircraft, I always wondered how the past was living in the future. How did we regress technologically?
The lack of supersonic civilized transportation is due to multiple reasons. Firstly, the uniqueness and the danger of the Concorde. The supersonic machine, jointly developed by two aviation giants, stood alone. The plane had no competitors. The Concorde’s first accident was in late July of 2000, where Air France flight 4590 crashed shortly after take-off, which led to the deaths of all 109 passengers and staff on board and four people on ground. Everything proceeded to go down-hill from there.
After the initial crash, people were concerned with the safety of the plane, leading to a decrease in passenger populace. Shortly thereafter was September 11, 2001, which drastically decreased flight travel. In 2003, British Airways and Air France announced the retirement of the Concorde, accrediting it to high maintenance costs and low passenger numbers.
The Overture Boom Supersonic next-generation supersonic airliner, the successor of the xb-1, is designed to minimize the disruptive sonic boom by utilizing advanced aerodynamics and low-boom technology. Traditional supersonic aircraft generate sharp shockwaves that merge into an intense pressure front, causing the characteristic loud boom when reaching the ground. To mitigate this, Overture employs a carefully sculpted fuselage, delta wings, and an elongated nose to distribute shockwaves more gradually rather than allowing them to merge into a single intense wave. This approach, known as “boom shaping,” spreads pressure changes over a longer distance, reducing the abruptness of the boom and resulting in a quieter “thump” rather than an explosive sound. Additionally, Overture is optimized to cruise over water at Mach 1.7 and operate at higher altitudes to further dissipate sound energy before it reaches the ground. Advances in computational fluid dynamics (CFD) and wind tunnel testing have allowed engineers to refine this design, ensuring that the aircraft remains commercially viable while adhering to evolving supersonic noise regulations.
With the announcement of potential supersonic travel emerging, talks of the supersonic boom lingers. People have addressed concern regarding the disruptive roar of the Concorde and they are not comfortable integrating that into their daily lives. This doesn’t pose an issue for two reasons. Firstly, the Concorde, and any planes breaking the speed barrier, only do so over water, the reason why transatlantic flights were the predominant usage of the Concorde during its lifetime. This means that the thunderous blast will only be heard over the ocean. Furthermore, by the US law enacted in 1973, no civil aircraft may fly over U.S. land while maintaining a speed above Mach 1 (14 C.F.R. § 91.817). The law was enacted by the government in a response to the imminent launch of the Concorde. Secondly, the xb-1– the supersonic aircraft designed for civilized travel by Boom Supersonic – successfully demonstrated a “silent” boom after breaking the sound barrier. The xb-1, an American aircraft, has proven to fly up to speeds of Mach 1.3 without an audible bang.
When an aircraft approaches the speed of sound (Mach 1), air molecules in front of it compress faster than they can disperse, forming shock waves due to the inability of sound waves to propagate normally. At subsonic speeds, these waves spread out evenly, but as the aircraft nears Mach 1, air pressure builds up, creating turbulence and increased drag. Once the aircraft surpasses Mach 1, it outruns its own sound waves, generating a conical shockwave known as a Mach cone. This shockwave consists of rapid compression and rarefaction of air molecules – compressed molecules experience a sudden spike in pressure and temperature, while those behind the shock front expand, causing a sharp drop in density. This abrupt shift in air pressure propagates outward and, upon reaching the ground, is perceived as a sonic boom. Unlike a single explosive event, the boom persists along the aircraft’s entire supersonic flight path.
The primary issue with the Concorde wasn’t the noise complaints. The costs of flying the supersonic machine as well as the declining passenger population found the program too expensive to retain.
The Concorde, while an engineering marvel, ultimately failed due to its overwhelming operational costs, low passenger capacity, and lack of economic viability. Its supersonic flights consumed immense amounts of fuel, ticket prices were exorbitantly high, and restrictions on overland supersonic travel limited its routes, making profitability nearly impossible. Combined with the 2000 Air France Flight 4590 crash and declining passenger confidence, airlines saw little incentive to continue operating the aircraft, leading to its retirement in 2003. Now, as Boom Supersonic aims to reintroduce commercial supersonic travel with the Overture, the key challenge remains: How can it succeed where Concorde failed? By leveraging modern aerodynamics, sustainable aviation fuel (SAF), and more efficient engines, Boom promises lower operating costs, reduced noise, and a broader market appeal.
However, with the same historical obstacles – fuel consumption, regulatory constraints, and infrastructure limitations – can the Overture truly overcome the financial and logistical barriers that doomed its predecessor, or is supersonic commercial flight still an unsustainable dream?