When asked about Gulfstream’s plans to develop a supersonic business jet, company president Larry Flynn said the company “continue[s] to invest in a very small way,” while concentrating on its core business.

A Gulfstream SSBJ would have to be approved to fly at supersonic cruise speeds over land, as well as over oceans, to be viable in the marketplace. Flynn says the Gulfstream Quiet Spike research program, which evaluated the shock-wave-noise impact of an F-15 fitted with a telescoping nose boom, indicated that reducing the noise signature of an SSBJ is possible. But, “we would have to have a demonstrator vehicle” to prove the technology to skeptics in North America.

Moreover, any change to current day restrictions regarding flying at supersonic speeds over land would require international agreement and formal acceptance by International Civil Aviation Organization member states. ICAO standards, covering aircraft noise and emissions, are established by its Committee on Aviation Environmental Protection (CAEP). But the committee only meets every three years. Thus, if Gulfstream, Aerion or another SSBJ developer were to submit data to CAEP in 2014, it wouldn’t be reflected as a world standard until 2017 at the earliest.

Perhaps an even greater challenge is engine availability. Current-production high-bypass-ratio turbofan engines won’t propel aircraft faster than Mach 1 in level flight. Any existing engine would have to be heavily modified to be adapted for use in a supersonic business jet. There are major development cost, fuel efficiency, TBO and maintenance cost challenges involved with such a program.

Meanwhile, Gulfstream is working on less risky programs, such as the G560ER, plus perhaps shorter- and longer-range variants. The G450, for instance, is getting long in the tooth, and it faces formidable competition from the upcoming Dassault Falcon 5X, a larger, roomier, longer-range and more fuel-efficient contender.

So don’t look for a Gulfstream SSBJ announcement anytime soon.