Aerion Corp. is seeking potential partners to build its proposed supersonic business jet and deliver the airplane to the market by 2011.

"We are keeping to an aggressive timeline moving toward routine supersonic business jet travel," said Brian E. Barents, vice chairman of the Reno, Nev.-based advanced engineering group. He says Aerion has resolved major issues surrounding the technical feasibility of an SSBJ, and "we are now able to present . . . a design that is well-researched and quite achievable."

Aerion unveiled its SSBJ a year ago at the National Business Aviation Assn. convention. In the last 12 months, however, a number of significant changes have been made to the original design. In addition, Aerion conducted a market survey of more than 1,100 operators of large business jets and determined there is demand for at least 250-300 supersonic jets.

The list of technical changes includes:

*Slightly altered wing geometry achieved by reducing total area to 1,200 from 1,400 sq. ft. and aspect ratio increased to 3.3 from 3.0. Leading edge sweep has decreased, while tip chord has increased, and raked tips have been added. Leading edge strakes have been modified to further improve low-speed and stall behavior. Aerion projects a balanced field length of 6,000 ft. for the SSBJ, which features a natural laminar flow wing design patented by the group.

*Split flaps added to the trailing edge flaps to reduce deck angle on final approach to land and to augment low-speed handling characteristics.

*Empennage redesigned to a low-mounted cruciform configuration instead of a T-tail arrangement. Barents says the change will provide improved stall characteristics and increase pitch authority for stall prevention and recovery.

*A fly-by-wire flight control system featuring "mild stability augmentation that allows us to tune handling qualities over a wide range of operating speeds," said Richard Tracy, chief technology officer. He says the airplane's flight envelope is 120 kt. in landing configuration to a high-speed cruise of Mach 1.6.

*Fuselage shape refined to have a vertical oval cross section in the forward area that expands to a constant-diameter circular cross section in the cabin.

Aerion Corp.'s studies indicate its supersonic business jet could cruise over land at Mach 1.15 and avoid any perceptible sonic boom at ground level.Credit: INFUSION DESIGN

*Raised cockpit floor, changed windshield angle and altered shape of the fuselage nose section to meet FAA guidelines for pilot visibility. The airplane will not use an artificial vision system or droop nose.

*Nose gear moved aft under the cockpit floor. As a result, turning radius has been reduced to less than 75 ft.

*Engine nacelles reconfigured to a nearly circular inlet from a rectangular shape.

Barents says these changes probably represent the final configuration of the SSBJ, although further alterations may be necessary if the program progresses, especially to the flight-test stage. He says the airplane is designed to achieve efficiency at speeds "just below Mach 1," which is currently the maximum speed over the U.S.

As for unrestricted supersonic flight over land, cruise speeds near Mach 1.15 would avoid "any perceptible boom at ground level," and at supersonic speed, the Aerion SSBJ's sonic boom is projected to be "relatively mild because of the airplane's low weight," says Barents. Supersonic flight is permitted over designated routes in remote areas of the world, such as Northern Canada, Siberia and Australia.

"As we move into serious discussions with potential partners, the test results to date give us great confidence that the Aerion SSBJ is an achievable dream," says Robert Bass, Aerion chairman. He says the technical and business cases for the program "are quite compelling."

In addition to Aerion, Supersonic Aerospace International (SAI), a group led by J. Michael Paulson, son of business aviation icon Allen Paulson, is developing their Quiet Small Supersonic Transport. SAI claims it has a patented design that would produce an "aerodynamically shaped sonic boom signature making it possible to secure legal permission to fly supersonic over populated land areas throughout the world," the company said. SAI, however, did not respond to Aviation Week & Space Technology requests to interview company officials for this story.