1976

The Concorde

The mid-1960s was aviation’s nirvana. The SR-71 was flying at Mach 3. Commercial jet service was routine. Humans would soon land on the moon. And the next big thing was on the horizon: the SST, or supersonic transport. There was a widespread idea that soon, very soon, everyone would be traveling at supersonic speeds. Instead of six hours to cross the US, it would take three.

So engineers began designing the future, and Europe had a huge lead, which is why the Concorde is a European aircraft. But even with the lead, engineers had a lot of problems to solve. Supersonic flight has a number of difficulties not experienced below the speed of sound.

Problem #1: Take off and landing. Supersonic flight favors short wingspans to cut drag. But short wings are terrible for takeoff and landing. Solution: extreme delta wings which, at a steep angle, have good lift at low speeds. Then the Concorde’s articulated nose lets pilots see the runway.

Problem #2: Thrust. To fly across the ocean at Mach 2, the engines need supercruise ability. And they need to be compact to cut drag. Solution: Pure turbojet engines with no bypass fans. Mechanical intake flaps slow down the supersonic air entering the engine. Afterburners give the engines extra power for takeoff and the jump to supersonic speeds.

Problem #3: Heat. At Mach 2, passing air heats the plane’s surface. The nose reaches 260°F (127°C). The plane’s interior is warm to the touch. Flying at 60,000 feet (18,300 meters) lessens the effect. Special aluminum alloys handled the heat, but also set maximum speeds because of the metal’s temperature limitations.

One problem engineers could not solve was the economics. Drag considerations limit the width of the aircraft, allowing fewer passengers. The extra speed demands extra power. The Concorde had 31,000 gallons (117,350 liters) of fuel on board for just 110 people in the cabin. A fully loaded 747 might use one-tenth the fuel per passenger mile, offering much cheaper travel. Engineers can do many things, but they can’t change the laws of physics and their economic effects. Cheap supersonic travel awaits a reconceptualization.

SEE ALSO Hall-Héroult Process (1889), SR-71 (1962), Lunar Landing (1969).

The Concorde landing at the Amsterdam Airport.