Prime contractors chasing big business retooling old fighters.

• Author: Parsons, Dan

* For the United States and its allies, the F-16 has proven time and again to be the perfect all-around, multi-mission tighter aircraft, and with ongoing delays in developing a revolutionary new plane, air forces are preparing to keep it flying for decades to come.

The F-16 is second only to the F-4 Phantom fighter jet in worldwide popularity. A little more than 4,500 aircraft have been produced since its introduction in the 1970s. More than two-dozen air forces have the F-16 as the core of their current fighter fleets.

While the relatively small, single-engine fighters have been in continuous service since 1978, many will be used well past their planned service lives. Onboard weapon and sensor systems are quickly becoming obsolete. Originally designed to fly 8,000 hours, industry is being asked to extend the fighter's service lives to beyond 10,000 hours and perhaps as many as 12,000.

With a global F-16 upgrade market estimated at more than $3 billion worth of work on about 3,000 aircraft, the largest defense contractors have joined the race, including Lockheed Martin, BAE Systems, Northrop Grumman and Raytheon.

Boeing executives expressed interest in pursuing F-16 upgrades during the Paris Air Show last month. Boeing manufactures the Navy's F/A-18 and the Air Force's F-15 jets. Both are sold internationally.

With fifth-generation fighters like the F-35 plagued with delays and cost overruns, many countries--including the United States--are faced with needing to upgrade their F-16 fleets. Some of the largest defense contractors in the aircraft industry are vying to capture business from various foreign air forces seeking such upgrades to the systems and airframes of their existing fighter fleets. The U.S. Air Force and those of Taiwan and South Korea represent the bulk of the overseas market, though the scope of business opportunities is expanding, industry officials said.

The number of F-16s that are still in operation worldwide make the upgrade business a fat target for firms competing to do the work. With more than 1,400 operational aircraft in service with allied air forces, "there certainly are a lot of aircraft to be addressed in the marketplace," John Bean, vice president of global fighter programs with BAE Systems, told National Defense.

"There are two factors out in the world. One is economies--whether it be the U.S. or international partners--are fairly constrained right now, so the financial resources to spend a lot of money on defense are fairly...