You may have seen some news about the progress of the Boom supersonic transport (SST) demonstrator, and that news raises the obvious questions: Will supersonic travel return? Should you care? The short answers are “Probably yes” and “Probably no.” If that’s all you care to know, you can go right to the sports or cooking pages or sites. Read on for more detail.
Boom Technology is an outfit building Overture, the first commercial SST since Concorde. Ideally, the first completed plane will be delivered to a customer in 2029. It will cruise at Mach 1.7 (about 1,100 mph) and carry 64 to 80 passengers up to a nonstop range of about 4,900 miles. Boom claims Overture will be able to offer seats at prevailing subsonic business class fares.
In support of its development, Boom built a smaller scale model that is currently flying. So far, all flights have been subsonic, but brief tests above Mach 1 are planned soon. Boom has already obtained permission to fly faster than Mach 1 over an isolated corridor in Nevada. From a technical standpoint, everything is so far going to plan, and Boom has signed a few dozen orders from major airlines.
- Supersonic cruising is feasible only over water, due to the loud sonic boom that supersonic flight produces along its entire flight path over populated areas. NASA is working on a low-boom supersonic design, but Boom isn’t counting on anything but overwater operations for Overture. That means supersonic nonstops are feasible only between the U.S. Northeast and westernmost European capitals such as London, Paris, Dublin, and Lisbon, or maybe from Tokyo to Seattle or Vancouver, but not San Francisco or Los Angeles. Even though a SST could do it, flights to/from the U.S. Midwest and central Europe is not feasible because of the amount of subsonic overland travel.
- A fuel stop adds close to two hours to nonstop flight time, so nonstop subsonics do about as well as one-stop supersonic trips.
- Supersonic flight gobbles up fuel. Concorde used several times the fuel per passenger than 747s did.
- SST economics when flying over land at less than Mach 1 are terrible, and so far I see no evidence that Overture would be able to fly economically on routes such as Chicago-London or Boston-Frankfurt with hundreds of subsonic miles to cover.
- Most planes capable of supersonic flight rely on gas-guzzling afterburners to cruise over Mach 1, and so far, only Concorde has been able to cruise three hours at Mach 2 without afterburner. Boom claims its engine partner will be able to avoid afterburner use, but that’s an open question for now.
Boom says that, unlike Concorde, Overture can be profitable at prevailing business class fares. Even so, those are high fares, compared to economy. And seating will be no better than today’s premium economy, compared with subsonic lie-flat beds at the same price.
All in all, I see a tough road for any SST except maybe a low-boom model that can fly over land. I flew Concorde (on a ridiculously cheap charter trip) from New York to Paris, and it was a real kick. But would I shell out thousands at list price? I don’t think so—and I don’t think many of you are likely to, either. So for now, Overture is an intriguing development, which I will follow with interest. But buy a ticket? Fuggetaboutit.
