Technology breakthroughs are reviving interest in building supersonic jets that would be much bigger and faster than the Anglo-French Concorde. No federal funding is being sought for development of a United States supersonic transport (SST). But support is quietly growing in some government and aviation circles for more research.
Several factors lie behind the new interest in the idea:
The belief that the US will need an SST in the years ahead to maintain ties with distant trading partners, especially Asia. The Concorde can't fly the Pacific nonstop.
The contention that the US needs to press ahead with research on a broad range of advanced aircraft -- including supersonics -- if it is to remain competitive in world aerospace. Technology in the field is advancing so rapidly, some argue, that most of today's aircraft may be obsolete by the year 2000.
The belief that engineering solutions are within sight that should help overcome some of the technical and environmental problems that dogged the SST the first time around.
``What we're trying to do is get [supersonic transport] back to the point where it is at least considered,'' says Cornelius Driver, manager of the aeronautical systems office at the National Aeronautics and Space Administration's Langley Research Center.
Officially, the joint US government and aerospace industry effort to develop an SST ended in 1971, when Congress rejected it for economic and environmental reasons. But during much of the time since, companies such as Boeing and McDonnell Douglas have maintained low-key research efforts. So has NASA.
Last month, a White House scientific and technological advisory committee recommended that supersonic transport be given higher priority. While not committing the US to building an SST, the report released by White House science adviser George A. Keyworth II suggested basic research be accelerated.
More recently, the director of NASA's Langley facility, Richard H. Peterson, sounded a similar theme at an aerospace symposium in Washington. NASA officials say the technology exists or soon will to put up a second-generation SST within 10 to 15 years.
For their part, NASA planners have been working with a design that would weigh 40 percent less and travel 60 percent farther than the original 290-seat plan Boeing came up in the 1960s. It would also be more fuel efficient and quieter than the 100-seat Concorde. The NASA airliner would be capable of flying at 2.7 times the speed of sound, vs. 2.05 for the Concorde.
But noise remains a key concern. Experts believe it now is possible to build an SST much quieter than the Concorde at landing and takeoff. But there appears no solution yet for the problem of sonic booms. A new SST would likely have to be operated subsonically over land and supersonically over water.
The chief remaining snag is economics. Studies estimate that as many as 500 SSTs may be needed over the next 15 years. But gearing up to develop them could cost $3 billion to $5 billion, NASA estimates. This is beyond the reach of any one company. A recent Boeing analysis noted the up-front costs associated with an SST program would be several times the net worth of any US aerospace firm. ``A privately developed SST is not in the cards in the near term,'' says a Boeing official.
Given the federal budget deficits and entrenched suspicion about supersonic transport, few expect much, if any, new funding from Congress. So SST advocates are weighing other financing options, such as an industrial consortium or a public corporation.