Concorde: The legend too flawed to fly

There is a romanticism about flight that never escaped us. It was always a dream of us as a species. When we finally conquered the skies, we felt a sense of freedom never before known to man, a sense that we broke the constraints on us by taking the sky and expanding our domain. Once we took to the skies though, another thing appeared that we needed to take over: speed. A sense of detachment from reality as the world zipped by in a blur of colours and all noise seemed to vanish. As a result, we chased this sense of speed. And the most accessible form of high speed travel to us was the Concorde.

What made Concorde famous?

The speed. The Concorde was the first and to date only commercial plane to break the sound barrier, reaching a top speed of around Mach 2 and able to cruise easily at well beyond Mach 1. It is an aviation legend, and has more than earned its place in the aviation hall of fame. But in order to get to the hall, the Concorde was one of the most sophisticated planes ever conceived. So the plane's engineering was very sophisticated, starting with the wings.

The Wings

The Concorde's wings looked more like a giant triangle had been cut in two and stuck on the sides of the plane. This shape of wing is called a Delta wing, and is very common among super sonic planes and jets. But why use a Delta wing instead of a standard one?

A standard wing simply cannot withstand the stresses of supersonic flight. When an object breaks the sound barrier, it creates a massive shockwave known as a sonic boom. This shockwave can tear normal wings off a plane easily. But a Delta wing is able to dissipate that force more evenly across the entire length of the wing and maintain consistent lift at both subsonic and supersonic speeds, making ideal for a plane like Concorde.

But in order to generate the lift required to fly, the plane needs to be able to move. And for that it needs some engines.

The Engines

Concorde did not use a standard engine layout. It used 4 turbojets, not turbofans like most passenger planes of the era used. Turbofans are commonly used in passenger planes due to their efficiency and the ease of production. Further more, turbofans do not place nearly as much stress on the engine components as turbojets do, due to the lower speed air that enters the engine.

The Concorde used turbojets, which are much more high maintenance. Firstly, at mach speeds, air itself becomes... deadly. At those speeds, the air can do the same damage as a tsunami or a bomb, which poses a massive threat to the engine. The air at that speed can destroy all the engine components, meaning it has to be physically lowed down before entering the engine proper.

But how is this even possible? How do you slow down the air itself? Well, you need to use extremely complex geometry to slow down the air. What happens is that when the air impacts any solid structure at supersonic speeds, it generates a huge shockwave. This shockwave can be directed. If the geometry of the engine intake is correct, the shockwave can dissipate before reaching the inlet fan. This allows the air to enter the engine at a normal speed, meaning that the engine components will not be destroyed by the air.

But it needs to accelerate the air to higher speeds afterwards in order to maintain the high level of thrust required for supersonic flight. In order to that, the engine's compressors compress and superheat the air. Then the heated air is released through a constricted exhaust. this speeds up the airflow, creating more thrust and giving the plane the thrust it needs to go to supersonic speeds and beyond.

How were the passengers?

This was a commercial jet after all, so passenger comfort was a top priority when designing it. For the most part, they were treated in a manner comparable to royalty. The entire plane was first-class essentially, and passengers received the best treatment possible in the history of aviation until that point. This was the pinnacle of comfort while travelling. Nothing came close to Concorde. But there was one complaint people had about the plane.

Why did it fail?

The passengers were cramped. The plane only seated a hundred people, and the cabin felt very cramped. There were two big reasons for this. The first was the comparatively slender fuselage. This was done to minimise drag as much as was possible, as having a thick fuselage actually increases drag regardless of its shape. So the Concorde's fuselage was designed to be as thin as humanly possible. But the fuselage had to be fitted with miles of wires and hoses to provide power to the control surfaces located on the wings and the tail. This meant less room was available to the passengers inside, cramping them.

Another issue the Concorde faced was its dreadful fuel-to-passenger ratio. What does that mean? It means that for each passenger, it burned MUCH more fuel per unit distance than any other plane. For comparison, a Boeing of comparable size could carry over double the amount of passengers while burning half as much fuel. This meant that the Concorde's running costs were abysmally high, far beyond acceptable limits. But the running costs weren't the Concorde's Death Knell. No, it died due to a far more blunt weapon.

Concorde was limited to Trans-Atlantic and Trans-Pacific flights only. Why was that? This is because of all the problems that come with supersonic flight that made the Concorde not viable for overland flights. When an object breaks the sound barrier, a huge shockwave is generated. This shockwave is unbelievably strong, able to shatter windows and rupture eardrums miles away. This was so serious, the plane was not allowed to enter supersonic flight until it reached a certain altitude and distance from any land. But even this was just bearable, because something far more deadly and sorrowful killed the plane.

Air France Flight 4590: Concorde's death bell

Air France flight 4590 was one of the worst aircraft crashes in recent history. It was supposed to be a Trans-Atlantic flight from Paris to New York, but the Concorde crashed before it even gained any altitude. 2 minutes after takeoff, the plane crashed heavily into a nearby hotel, killing all 109 passengers in the plane and 4 people in the hotel. The cause of the crash was determined to be some debris that the plane ran over while accelerating to takeoff speed. The tire exploded, and sent debris into the left wing fuel tank and landing gear, severing some key electrical control lines and rupturing the fuel tank, which began leaking. This leaking fuel was ignited by the electrical wires, feeding fire into the left-hand side engines. The landing gear couldn't be retracted as well, because the wires were broken. This made the plane uncontrollable, and it sadly crashed, killing 113 people.

This was the only fatal accident in the plane's history, but its reputation was destroyed. The Concorde's reputation as one of the safest airplanes to exist was gone. It took the BEA (the French accident investigation board) a full year to determine the cause of the crash, and during that time, all Concorde flights were grounded. But just as Concorde flights resumed (with all planes changed to prevent this from happening again) the 11 September attacks took place, and air travel in general became less frequent. Finally, in 2003, all Concordes were retired, never to be flown again, with British Airways and Air France stating financial reasons for the plane's retirement. The last Concorde flew on October 24, 2003.

Why is it such a legend?

This is a good question when you think about it. It failed its role as an aircraft that was supposed to be commercially viable. So why? Why do we idolise a failure?

It's less about the fact that it failed its intended role as a supersonic commercial jet, and more about the fact that it was a marvel of engineering. The Concorde was a testament to the ingenuity of mankind, a showcase of just how far we could push technology when we really pushed the limits. Concorde was never really designed to be viable, if we are honest. It was designed specifically to break the sound barrier, and be little else apart from one of the greatest engineering feats ever to exist. It's a testament to our engineering prowess and our ingenuity as humans.

Concorde was not perfect. It was flawed, just like any other plane was. But it achieved something no commercial aircraft before or since achieved, and more than deserves to be called a legend.