Mach 1 for Millionaires
Briefcase-toting suits who travel in bizjets-those will be the next pioneers in supersonic flight.
- By Mark Huber
- Air & Space magazine, March 2006
NASA Langley Research Center
(Page 3 of 9)
An aircraft experiences a certain amount of drag from skin friction as air moves across the wing and gives rise to turbulent “boundary layers.” Laminar flow describes air immediately next to the wing, which flows in a series of smooth layers, free of turbulence, resulting in less aerodynamic drag on the wings and improving range, speed, and fuel economy. It is virtually impossible to achieve extensive laminar flow on a subsonic aircraft. Supersonic aircraft offer more possibilities, but their potential for laminar flow is often defeated by design factors, like a highly swept wing, which invariably creates turbulence and drag.
NASA experiments in 1995 and1996 used the delta wing on an F-16XL fighter jet, modified with a power-suction “glove,” to improve laminar flow. According to laminar flow expert and aerodynamicist Richard Tracy, a normal F-16 wing “has too much sweep to support laminar flow and has a slightly blunted [wing] leading edge…and thus a very high wave drag at its maximum supersonic speed.”
While suction gloves seek to improve laminar flow on swept-wing designs, natural laminar flow relies on a wing’s shape alone, without help from other devices. Greater wing sweep produces greater turbulence, thus a natural laminar flow wing has very little sweep, a design that helps stabilize airflow.
The first widely known aircraft to take advantage of this principle was Lockheed’s F-104 Starfighter, a Mach 2 interceptor developed in the 1950s. In 2000, NASA and DARPA teamed up with the Reno Aeronautical Corporation to demonstrate a three- by four-foot natural laminar flow test article mounted to the belly of an F-15B fighter and flown up to Mach 2 at 45,000 feet. The demonstration validated the theory and led NASA to speculate that natural laminar flow had the potential to enable supersonic aircraft to produce “economies comparable to, and in some cases better than, subsonic aircraft in the same role.”
Based on these latest rounds of research, two camps sprang up to test the market.
Supersonic Aerospace International was founded in 2001. It is funded by the estate of Clay Lacy’s friend Allen Paulson (see “The Used Airliner King,” below). Aerion was founded in 2002 and is bankrolled by Texas billionaire Robert Bass.
In 1978 Allen Paulson purchased Grumman’s foundering line of civilian aircraft, including the Gulfstream business jet. Over the next decade Paulson shaped Gulfstream into the ultimate status symbol. From corporate chieftains to foreign potentates to the glitterati, nothing said “Mine’s bigger” quite like a Gulfstream.
By 1985 Allen Paulson had parlayed his 1978 $58 million purchase of Gulfstream into a $637 million cash and stock sale of the company to Chrysler, but stayed on to run the company. He had also launched a wildly successful follow-on aircraft, the G-IV, a 4,000-nautical-mile-range model with all-digital avionics and more fuel-efficient engines. By 1988, Paulson knew what the next big thing was: supersonic.
In 1989 he teamed up with Mikhail Simonov of Sukhoi to develop the Gulfstream-Sukhoi SST, the S-21. Under the plan, Sukhoi would build the airframe while Gulfstream would be responsible for integrating the engines and avionics. The marriage would be short-lived: Chrysler elected to cash out of Gulfstream later that year. The company’s new owner was the New York investment banking firm of Forstmann-Little, and it became clear very quickly that the prime target on its radar was not a supersonic bizjet. “In the early 1990s, Gulfstream bet the company on the [development of the long-range, subsonic] G-V,” says Pres Henne, Gulfstream’s senior vice president for Programs, Engineering, and Test. “Anything else was a very low priority.”