By Marina Malenic

Additional international interest in a stealthier version of the F-15 Eagle has caused Boeing [BA] to plan for internally funded flight-testing in the third quarter of next year, a company executive has said.

“That flight test will probably happen sometime toward the third quarter of next year,” Tom Bell, vice president of business development for Boeing military aircraft, told Defense Daily last week. “We are determined to fly it and to demonstrate that the technologies inherent therein are real.”

The company unveiled the concept for the F-15 Silent Eagle early this year. The improvements in the new version are to include low-observable coatings and treatments on various parts of the aircraft; conformal fuel tanks (CFT) redesigned as weapon bays; vertical tails that produce lift on the back of the aircraft, thereby extending its range; and a digital electronic warfare system produced by BAE SYSTEMS (Defense Daily, March 18).

At that time, Boeing executives announced that a flight-test program would begin in the first quarter of the next fiscal year. The delay of about six months, according to Bell, is to accommodate “unexpected” additional international interest. The delay will buy the company some time to “assess how we can bring them into the program,” Bell said.

He declined to specify the potential international buyers in question.

Boeing is challenging Lockheed Martin‘s [LMT] bid for a South Korean fighter contract with the Silent Eagle. Lockheed Martin is pitching the F-35 Joint Strike Fighter in that competition. The South Korean Air Force currently flies Boeing’s legacy Slam Eagles.

Bell said that, in many markets around the world, the Silent Eagle will hit both a financial and capabilities “sweet spot” for countries looking for a technology upgrade at a reasonable price.

“We’re offering the lowest risk, lowest price solution for this level of capability,” he said.

According to defense industry analysts, other likely potential customers include Israel, Japan, Singapore, and Saudi Arabia.