JAXA’s SST: Third time the charm?

September 1, 2006, by Bill Cawthon

The United States never built them, the Europeans and Soviet Union built them and flew them but gave them up. Now the Japanese are going to try their hands at building a workable and, hopefully a commercially viable, supersonic passenger plane.

Two concepts for a Japanese supersonic jetliner. Images courtesy of JAXA.

About a week ago, the Japan Aerospace Exploration Agency (JAXA) made a splash by setting a goal of developing a prototype supersonic transport (SST) within six years. The agency hopes to build a plane that will be both quieter and more fuel-efficient than the Aerospatiale-BAC Concorde which was retired in November 2003.

The SST has been one of the holy grails of the aerospace industry since Chuck Yeager showed it was possible to fly faster than sound in 1947. Supersonic transports were described in glowing terms in Sunday supplements throughout the 1950s and no doubt a person magically transported from that time to 2006 would be surprised and perhaps disappointed to find they aren’t in common use today. Of course, based on the popular press projections from those days, they would also be surprised we don’t have atomic flying cars.

There was no shortage of effort, as national pride was on the line. Aircraft builders in the U.S., Europe and the Soviet Union all poured money into their own SSTs. Under a program set up by President John F. Kennedy in 1963, the federal government would shoulder three-quarters of the development cost for an American SST to compete with the Concorde being developed by a British-French consortium. It was estimated there would be a worldwide market for five hundred SSTs.

Unfortunately for the dream, the reality of the SST was somewhat different. There were huge challenges to be overcome, from wing design to managing air flow into the engines. Conventional jet engines don’t react kindly to intake air moving at supersonic speeds so a method had to be developed to slow the air down. Considering the plane has to move through the air faster than the air can flow through the engines, that’s quite a conundrum.

Even factors like solar radiation came into play. At the altitude a supersonic jet needs to fly, about 60,000 feet, solar radiation is more intense and prolonged exposure could be a hazard. It was eventually determined the SST’s shorter flight times compensated for the increased radiation levels, but the Concorde was still fitted with instruments to measure the radiation in case the plane needed to descend to a lower altitude for passenger safety.

While the engineers could overcome the technical problems, there were others that plagued the SST and some of those were serious. When a plane crosses the sound barrier, it creates a shock wave and the bigger the plane, the bigger the wave. When we hear it, we call it a sonic boom and it can be quite disturbing. In the early days of SST research, it was believed higher ceilings would reduce the problem. However, when the U.S. Air Force started flying the North American B-70 Valkyrie in the early 1960s, it was discovered the boom was still a problem even at 70,000 feet. It was this problem that contributed to the abandonment of the Boeing 2707-300 SST in 1974, even though Boeing had more orders for their plane than had been placed for the Concorde.

An artist’s conception of one of Boeing’s early SST designs. The weight of the machinery required for the swing wings forced a later changed to a fixed delta wing before the project was cancelled. Image courtesy of the Boeing Company.

The Concorde, on the other hand, made it to production and flew in commercial service for more than a quarter-century. But the anticipated market never developed. Instead of five hundred SSTs, only twenty were built and just fourteen of those flew in commercial service. Heavy restrictions by many nations limited the routes the Concorde could fly and its prodigious appetite for fuel made it expensive to operate and required fare significantly higher than those required for slower jetliners. In addition, with no new market to justify further development, the planes were not upgraded and lagged far behind other aircraft in sophistication. Sort of like the muscle cars of the late 60s and early 70s. They were also fast and loud, and lots of us still have a warm place in our hearts for them, but the sad truth is that numerous modern cars with fewer cubic inches of displacement can outrun them.

JAXA believes the newer technologies developed in the past thirty years will help it develop an aircraft capable of making the trip from Tokyo to Los Angeles, a distance of almost 5500 miles, in three hours. After spending ten years in research, the agency is now devoting 20 billion yen (about $170 million) to developing a prototype of a plane that could be carrying up to three hundred passengers per flight by 2020.

Flight test of a large scale model of the Japanese SST. Left, on the launcher. Right, the model lifts off for a 15-minute flight in October 2005. Images courtesy of JAXA.

The development initiative is important for the Japanese, who could use a high-profile breakthrough to give them a more competitive position in the aerospace industry. Despite its incredible success in other fields, Japan lags well behind the United States, France and Russia in aircraft development and has produced only one significant commercial airplane since World War II. The YS-11 turboprop built by Nippon Aircraft Manufacturing Corporation was well-received when it made its debut in 1962, but it was not a commercial success with just 182 sold when production ended in 1974.

There are already some encouraging signs. Flight tests of large scale models of proposed designs were made at a test range in Woomera, Australia, in July 2002 and October 2005. The October flight lasted more than fifteen minutes and the model reached an altitude of nineteen kilometers (over 62 thousand feet) and a speed of Mach 2 before coming back to ground for a soft landing.

Though real-world testing has yielded mixed results, JAXA has successfully a new engine has that could theoretically propel an aircraft to Mach 5.5, roughly 3,300 miles per hour at an SST’s operational altitude of 60,000 feet. Gee, at that speed one could have a dinner in Tokyo, catch a flight and arrive in time for an early breakfast in LA: on the same day.

The goals for the Japanese program are significant: a fifty-percent reduction in noise and improved fuel economy, combined with advances in avionics and flight control. But JAXA scientists and engineers are confident they can deliver the goods.

But the question remains: is the world clamoring for a new, super-fast airplane? The Europeans couldn’t see enough future in their SST to upgrade it. The Soviet Union grounded their TU-144 in 1978 after just 102 flights. In March of 2001, Boeing announced plans to develop a new plane, called the Sonic Cruiser (see “The Return of the Cool Airplane”) that would fly close to the speed of sound. By the end of the following year, the Sonic Cruiser program was shut down, a victim of the new realities of the air transportation industry. However, JAXA sees growth in the future of air travel, especially in the Asian region where the long distances routinely flown might make extremely rapid transit attractive to travelers who would otherwise spend hours and hours sitting in an airplane and there is enough wealth flowing into the region to ensure a good pool of well-heeled passengers who could afford to pay higher airfares for shorter flights. Perhaps the next cool airplane will come from Japan.

Herpa will be producing these 1:200 Wings models. Top: USAF F/A-22 Raptor, America’s newest air superiority fighter. Bottom: The Sukhoi SU-27UKB a training version of the Russian Air Force’s most competent fighter. Images courtesy of Herpa and Promotex.

Speaking of fast planes, we’re still waiting on a couple from Herpa. I’m talking about the new 551472 USAF F/A-22A Raptor and the 551519 Russian Air Force Sukhoi SU-27UBK in 1:200 scale. The Lockheed-Martin F/A-22 (F/A means Fighter/Attack) has a maximum speed said to be in excess of 1600 miles per hour (Mach 2.42) and it is the Air Force’s multi-role air superiority fighter for the future. Combining stealth technology and engines that allow the plane to achieve supersonic speeds without the use of afterburners, thereby increasing the jet’s range, the Raptor is designed to outclass any existing combat aircraft. Nobody is giving out specifics but due to its thrust-to-weight ratio, the Raptor has an initial climb rate greater than fifty thousand feet per minute. Since entering service in December 2005, the Raptor has been officially designated the F-22A.

The Sukhoi SU-27UBK is a training version of the SU-27 Flanker, another air superiority fighter that went into service in the 1970s. It also boasts a top speed in excess of Mach 2.0 and has been reported to be able to climb faster than the legendary F-15 Strike Eagle. Painted in the light blue colors of the Russian Air Force, “Blue 43” sports the St. George shield on its tail.

These models along with a replica of the F-14 Tomcat wearing the “Jolly Roger” colors of the U.S. Navy’s Fighter Squadron VF-84 are included in Herpa’s summer releases. The Tomcat has been immortalized in a number of movies, including “Top Gun,” which is mentioned by Herpa in their description of the model. However, Cruise was assigned to the VF-1 “Wolfpack” Squadron, not VF-84. The Tomcat was the last aircraft type assigned to VF-84, one of a series of “Jolly Roger” squadrons which date back to a famous Corsair squadron formed in World War II. The Jolly Roger currently adorns the F/A-18 Super Hornets of Squadron VFA-103, which was given permission to use the insignia after VF-84 was disbanded in 1995.

Here in the U.S., we’re getting set for the last holiday of the summer season. I hope you have a pleasant Labor Day and if you’re driving, please remember to buckle up and be extra careful on the highways.

See you next time!

- Bill Cawthon

Bill Cawthon is a modeler and collector. His primary hobby interests are vehicle models in 1:87 and 1:160 scales and model railroading. He is one of the creators of the award-winning "Grimy Gulch" model railroad layout.

In real life, Bill is a marketing and public relations consultant working with the information technology and hobby industries. He is an associate editor for Model Railroad News and writes a monthly column on the U.S. light vehicle industry. He is a member of the 1/87 Vehicle Club and the Texas Auto Writers Association.

He lives in Houston, Texas with his wife, Marge, and their children.

Bill's columns appear twice monthly on Promotex Online. To learn more about him, click here.