Boeing Gives Sst A Second Look Supersonic Jet Could Be Ready As Early As 2015

Malcolm MacKinnon is “Mr. SST” at Boeing these days.

MacKinnon, program manager of Boeing’s High-Speed Civil Transport (HSCT), is careful to point out he heads a “technology development program, not an airplane development program.”

But then he proudly shows off a 4-foot model of the HSCT he thinks Boeing could launch between 2006 and 2009.

It will carry 300 passengers 5,000 miles. “This thing has to fly the Pacific nonstop.”

It will cruise at Mach 2.4 - about 1,600 mph, three times the speed of any jetliner Boeing builds now.

The HSCT will be three times the size, have twice the range and be 20 percent faster than the British-French built Concorde, the only supersonic plane in passenger-carrying service at present.

MacKinnon heads a team of about 350 engineers at the world’s largest commercial jet transport manufacturer, counting former McDonnell Douglas employees in Long Beach, Calif., and a few in St. Louis.

About 80 percent of those folks are working on research Boeing is doing under contract with the National Aeronautics and Space Administration. A lot of research has been done, MacKinnon said, but a lot more is needed.

The other 20 percent are doing Boeing-funded product development, MacKinnon said, “to make sure there really is an airplane there.”

“We got started in this round of SST work in 1987, when NASA asked us to do a brief study to see if there was a commercial application … for what was then called the National Aerospace Plane, a single stage-to-orbit space vehicle,” MacKinnon said. “We very rapidly came to the conclusion there was no synergy at all between carrying passengers and that kind of vehicle - not in the next 50 or 100 years.”

But in the 30 years since Boeing tried in vain to get an SST off the ground, things have changed in ways that made a less grandiose scheme - a new High-Speed Civil Transport - seem more feasible.

First, air travel has exploded, particularly on long-range routes like those across the Pacific Ocean.

Second, advanced technologies have come along that promise solutions, MacKinnon said, “that weren’t possible for the old SST or the Concorde.”

Third, “We have a better handle on environmental issues than we had 30 years ago” when “environmental research was principally emotion and not data.”

But a new HSCT would be “such a high-risk project, with no guaranteed return on investment,” MacKinnon aid, that “it was not something private industry would do on its own. NASA would have to help.”

NASA undertook a “$300-odd million program” of High-Speed Research, MacKinnon said. Phase 1 was “primarily aimed at seeing if there were any environmental show-stoppers.”

The environmental concerns are tough ones:

Sonic boom. Planes flying faster than Mach 1 leave a pressure wave that makes a sound like a cannon shot and can rattle dishes or break windows.

Air pollution. Jet engines operating at altitudes around 60,000 feet emit oxides of nitrogen that can catalytically damage the ozone layer.

Community noise. MacKinnon said engines for faster airplanes are very noisy and have to be made quiet. Noise suppressive jet exhaust nozzles are part of the solution.

Boeing now is about midway through Phase 2 of NASA’s High-Speed Research program, to be completed in 2001.

This phase is exploring advanced aerodynamic considerations.

“At Mach 2.5, skin temperatures go up to 350 degrees Fahrenheit. That’s too hot for aluminum,” MacKinnon said. “So we have to come up with advanced materials” that can be lightweight and withstand the temperatures involved.

“We didn’t want a droop snoot like the Concorde has,” MacKinnon said, so NASA used the first-ever 737 to develop an “external vision system” where cameras project the exterior view onto flat-panel cockpit displays.

Speaking of cockpits, the one in MacKinnon’s HSCT will be 55 feet in front of the nose wheel. Boeing has been driving a framework representation of that layout around Moses Lake’s airfield for some weeks, testing ground handling qualities.

Boeing’s HSCT would exert the same ground pressure on runways and ramps; it would use the same gates, “fit in the same square,” MacKinnon said, as 747s.

It would use the same approach speed, MacKinnon said, but it adds immensely to the expense of manufacturing.

“Every time we look at it, we try to eliminate it because it’s a manufacturing expense,” MacKinnon said, to form flat sheets of aluminum into compound curves.

But the alternative is to increase engine size to muscle through the “very draggy” transonic speeds, and that would ruin fuel efficiency at subsonic and supersonic speeds.

Using composite materials for the HSCT, rather than aluminum, may make compound curves “not so big a deal,” MacKinnon said.

Still, the HSCT would be an expensive proposition. How much would it cost? “Well, like they used to say about Rolls-Royces,” MacKinnon quipped, “if you have to ask, you can’t afford it.”

Then he sobered slightly and said it would cost about twice what Boeing’s 777 costs.

The 777-300 lists for $150 million to $170 million.

“But this airplane’s productivity will be twice that of a regular plane,” MacKinnon said. “If you can fly a route in four hours instead of 10, you can make two flights a day instead of one.”

“In that sense,” he added, “this isn’t a 300-passenger 5,000-mile airplane, but a 600-passenger 5,000-mile airplane.”

Emphasizing again that he’s only talking about “what’s possible from a technical point of view,” MacKinnon said the HSCT could be in service perhaps by 2015. He predicts a market for 1,500 HSCTs by 2025.

But only if infrastructure can be accelerated so total trip time is reduced.

“A lot has to happen before this will work,” MacKinnon said.