It might just be symbolic that on a leap day, NASA administrator Charlie Bolden announced plans to build a quiet, supersonic X-plane as a test bed for future air travel. The $20M Quiet Supersonic Technology project, or QueSST, was awarded to Lockheed-Martin and subcontractors GE Aviation and Tri Models. Its purpose is to create a preliminary test aircraft to pave the way for future civilian supersonic travel. The main goal is to do away with the massive sonic booms created by supersonic aircraft and replace them with a softer “thump.”
Why Did Supersonic Travel Fizzle in the First Place?
I can remember as a child living outside Washington, running outside to see the Concorde fly over on its way to Dulles airport. The sleek, smooth lines of the worlds first supersonic passenger liner were futuristic, and everyone thought we’d soon be traveling from New York to Tokyo in a matter of hours. But, while the Concorde was marginally successful as a commercial endeavor, the concept never really caught on beyond it. One of the main reasons was the sonic boom created when in supersonic flight. The aircraft was prohibited from flying above the speed of sound when over land. If you’ve never heard a sonic boom up close, you’d understand why this was necessary. As a Space Shuttle engineer working landings at Edwards Air Force Base, hearing the booms was a common occurrence, as test pilots flew supersonic aircraft over the base’s dry lake bed. I’d like to say you got used to them, but you never did. The entire wall of our trailer would bow in and out when a boom hit. Residents under a civilian flight path wouldn’t stand for too much of that. Limiting aircraft to subsonic speeds for a substantial portion of a flight, takes away much of the reason for operating them in the first place.
Additionally, the Concorde was also expensive to operate, both in fuel and maintenance. As a comparison to other aircraft from the era, for a 747-100 to fly from New York to London, it consumed 24,400 gallons fully loaded. A Concorde consumed about 17,200 gallons. That might seem like the Concorde won out, but it carried only about 100 passengers, while the 747 carried more than 400. On a per-passenger basis, the Concorde was about 1/3 as efficient as the 747 – and it was much more cramped. My grandfather flew on the Concorde once and said he’d never do it again – it was just too uncomfortable.
Lastly, the Paris crash of a Concorde – Air France flight 4590 – on July 25, 2000 seemed to seal the deal. The crash was caused by a piece of debris on the runway from an earlier Continental Airlines DC-10 flight. It punctured a tire and sent debris into the underside of the wing, which caused a pressure wave that ruptured a fuel tank, causing the fuel to catch fire. Two of the aircraft’s four engines lost power, one of them regained it. The aircraft was traveling too fast, and too little runway remained (1.2 miles and it needed 1.9), so the crew had to attempt a takeoff. Now airborne, the damaged landing gear could not be retracted, which slowed the aircraft. Additionally, the engine that originally had regained power, lost it again. Now slow, and with thrust on only one side of the plane, it struggled to maintain flight, banked more than 100 degrees, and crashed. While the cause was the debris, the entire episode was accentuated by the complex nature of the Concorde and its relatively poor low speed handling characteristics. It is possible that a more conventional aircraft would have recovered. While Concorde flights continued until 2003, the crash had shaken public confidence and contributed to its retirement.
Why Travel Supersonic?
The lure of being able to travel around the globe in a fraction of the time of current air travel has spurred designs of supersonic and hypersonic aircraft for decades. Simply put, faster travel will open up the world, and people want less time in transit. One company is betting on business travel. Spike Aerospace announced plans in 2014 for the world’s first corporate jet – there are plenty of wealthy executives and companies willing to spend money to save time. Still, without dealing with the sonic boom, the benefits would always be tempered.
When Will it Happen
The hope is for Lockheed to have an operating 50% scale model by 2020. Obviously, a functioning commercial aircraft couldn’t hope to enter service until at least a decade after that, but possibly within 15 years, we will cease seeing bulky passenger liners at airports and start seeing sleek, needle-nosed supersonic planes.
NASA aims to make “flight greener, safer and quieter — all while developing aircraft that travel faster, and building an aviation system that operates more efficiently.”
NASA Administrator Charlie Bolden
Image credits: NASA, AP, Spike Aerospace