It is 7.00pm when the supersonic business jet returns to New York after another normal working day for its passengers. They had left just 12h earlier for a 2h meeting in Moscow and are returning in time to have dinner with their families. Tomorrow it will be Tokyo…
Supersonic flight has been a holy grail for civil aviation ever since Chuck Yeager broke the sound barrier. But only the Anglo-French Concorde and Soviet Tupolev Tu-144 made it into service - and the latter only briefly. Boeing's 2707 supersonic transport (SST) was cancelled in 1971 when the US Government withdrew funding, and the company returned the favour last year when NASA's High Speed Research (HSR) programme was cancelled after Boeing withdrew, citing the lack of a market.
The story is the same in Europe, where SST work is essentially dormant. But the hopes for everyday supersonic flight are not dead. They have shifted to a different market - business aviation. Leading the charge is Gulfstream, which has teamed with Lockheed Martin Skunk Works to study ways to minimise the sonic boom and allow routine supersonic flight over land - seen as critical to the market success of a supersonic business jet (SSBJ).
Dassault also continues to study a supersonic business jet, the Falcon SST. Galaxy Aerospace would like to participate in an SSBJ development through shareholder Israel Aircraft Industries - if there is a market.
Gulfstream believes there is. "Three independent market surveys say the market is there, and it's a Gulfstream-sized market," says Pres Henne, executive vice-president programmes. Customer surveys show the 12,000km (6,500nm)-range Gulfstream V meets all their range needs, the company says, leaving flight time as the next frontier. "They're saying to us they want to go faster," Henne says.
The manufacturer is studying an SSBJ with a range of at least 7,400km and cruise speed of at least Mach 1.6. "Mach 2 brings temperatures and complexity that is not traditional Gulfstream," he says, adding: "A GIV-sized cabin is a basic requirement." Dassault's SSBJ would have a smaller, Falcon 50-sized, cabin and a similar range at a M1.8 cruise speed.
An SSBJ is still at least 10 years away, Gulfstream says. It is working with Lockheed Martin on a plan to fly a technology demonstrator within five years, to test boom suppression techniques developed by the Lockheed Martin Skunk Works. Other work on reducing engine noise and emissions will build on NASA's now-defunct HSR programme. The availability of suitable engines remains an issue.
Some believe a smaller SSBJ could be available sooner and cheaper. University of Kansas professor Dr Jan Roskam calculates that a M2/-7,400km "supersonic Learjet" with a Citation Jet-sized four-passenger cabin could cost $20 million compared to $54 million for a GIV-class SSBJ. At those prices, it is not surprising that customers expressing the most interest are fractional ownership operators.
Source: Flight International
