They’re just too darned loud. Complaints from those on the ground over supersonic booms caused the demise of the potential super speed flights. Well, that and a horrible crash that happened in 2000. More on that below.
Back un 1947 a rocket-powered aircraft broke the sound barrier achieving a goal to go faster and higher, but not taking into account the sonic booms that were heard by people on the ground.
Supersonic Booms
A mysterious phenomenon happens when an airplane flies faster than the speed of sound – sonic booms. At first it wasn’t clear what was causing this strange occurrence. After some research, it was discovered that atmospheric shock waves are generated when an aircraft travels faster than the speed of sound and what we hear as a result of that is the sonic boom.
As the US military sent more and more supersonic jets into the air for research, greater numbers of Americans who lived near those locations were tests were taking place were exposed to the alarming sound of the sonic booms. This was not met with much appreciation for military testing procedures.
Along with research on sonic booms came studies on how these noises may affect buildings. Loud noise can rattle structures just like ground shaking. Those in residential areas said their windows would rattle when a sonic boom happened.
In May of 1968, the Air Force Academy in Colorado held a ceremony during which an F-105 Thunderchief fighter jet broke the sound barrier flying 50 feet over the school grounds. The sonic boom created from that flight blew out 200 windows on the Air Force Chapel and injured a dozen people.
With all the strong negative feedback coming from the public , the US federal government instituted a ban on all civilian supersonic flights over land. This alleviated concerns over possible property damage from the effects of the booms on buildings and of course stopped the unexpected loud noise from startling citizens on the ground.
The Supersonic Crash Heard Round the World
Despite all this brouhaha over sound, the Concorde supersonic aircraft was designed in the 1960s by the UK and France as a commercial airplane which put 14 aircraft for 27 years into service from 1976 to 2003.
What literally brought the supersonic flight industry down was a fatal crash on July 25, 2000, when Air France flight 4590 killed all 109 passengers and crew on board as well as 4 people on the ground at Charles de Gaulle Airport in Paris.
The supersonic aircraft ran over a titanium strip that had fallen from a previous flight and was still on the runway which caused a tire on the Concorde to blow out, and those fragments from the tire blowout were thrown into the underside of a wing which damaged a fuel tank.
As the Concorde unknowingly continued to take off, fuel was leaking which caused an engine fire. Suddenly the aircraft lost stability and the flight crew was unable to keep control of the aircraft. Despite trying to turn back to the airport for an emergency landing, the Concorde crashed into a hotel
As the aircraft continued its ascent, a significant amount of fuel started leaking from the damaged tank. This fuel leak led to a fire on one of the engines and the wing, severely impairing the aircraft’s performance and stability. The flight crew struggled to maintain control, but the situation quickly became untenable.
With a loss of power and control, the Concorde attempted to turn back to Charles de Gaulle Airport to make an emergency landing. However, the aircraft was unable to gain the altitude needed to make the turn and instead crashed into a hotel in Gonesse town, bursting into flames on impact.
NASA Says Shhh
Today NASA continues to work on solving the sonic boom dilemma. The X-59 aircraft that has been developed is made to break the sound barrier with a much-reduced noise factor. Instead of a sonic boom, NASA calls it a sonic “thump.”
This new aircraft by NASA is called Quesst, and it’s described as a quiet supersonic. The hope is that once the results of this new aircraft are presented to US and international regulators, new rules will be considered that would allow the civilian flight ban to be lifted.
As NASA has been busy developing this new quieter supersonic aircraft, also on the list of concerns being addressed are emissions and climate impact that are currently under study.
