SONIC BOOMS AROUND FOR ONE MORE DECADE.

Byline: Lisa Friedman Washington Bureau

It could be a decade before the military or commercial airline companies make practical use of $7 million in new research aimed at reducing sonic booms, defense officials said Wednesday.

And the next generation of supersonic aircraft is expected to be leaner, sleeker and more fuel-efficient than the F-5E fighters that defense contractor Northrop Grumman modified to prove that quieter booms are possible.

``It throws the door wide open for development of vehicles of that type,'' National Aeronautics and Space Administration program manager Richard Wlezien said Wednesday, displaying an artists rendition of a future supersonic aircraft.

But, he said, ``It really takes a company taking this on. A company has to make a decision whether they have the technology to make this possible.''

On Aug. 28, Northrop Grumman announced that it had proved that sonic booms could be reduced by modifying an aircraft's shape. The research could pave the way for easing restrictions on certain military aircraft or the Concorde passenger jet.

Supersonic aircraft are restricted to flying over designated test ranges, while the Concorde is restricted to trans-Atlantic flights.

Steven Walker, program manager at the Defense Advanced Projects Research Agency, which jointly sponsored the sonic boom research with Northrop Grumman and NASA, said the U.S. Air Force is studying the newly released research as it decides where it wants to put its money for future strike systems.

Wlezien said the next logical commercial step would be the creation of a small, supersonic transport. But defense officials agreed Wednesday that practical applications won't be seen for five to 10 years.

``While supersonic flight today is doable, its not very efficient,'' Wlezien said.

For the sonic boom research, the Navy F-5E was outfitted with a specially shaped nose glove that Northrop Grumman program manager Charles Boccadoro said was built with 22 new frames and bulkheads.

``It's much more substantial, I think, than a glove. It's built to last,'' he said.

The defense contractor held the first test flight June 1 in St. Augustine, Fla., flying across the country and landing in Palmdale to complete the supersonic in-flight checkout, known as the envelope expansion.

The research culminated last week at Edwards Air Force Base when two jets were flown over a test range with ground sensors measuring the sonic booms clearly showing a reduced intensity with the modified fuselage.

``These are about as unambiguous results as you can get,'' Wlezien said.

Lisa Friedman, [phone]

lisa.friedman(at)langnews.com