Lockheed Martin has received a US Air Force F-16 Block 50 fighter set aside to undergo a three-year series of fatigue life tests that will play a major role in deciding the fate of hundreds of similar aircraft.

Over the next 15 years, the USAF inventory is projected to dip as much as 10% below the required threshold of 2,000 fighters. As a result, service officials are considering extending the service life of as many as 300 F-16s by as much as 50%, to 12,000 flight hours.

But first the USAF must find out how much service life remains among the roughly 1,130 F-16s currently in service, and what repairs are required to keep some of the aircraft flying.

 USAF F-16 - News Pictures/MCP/Rex Features
© News Pictures/MCP/Rex Features

Lockheed plans to start the three-year, continuous testing process that will log the equivalent of about 24,000h of flight time on the airframe.

"The USAF is about to put us under contract," says Bill McHenry, director of F-16 business development.

Air force officials have not been eager to invest in prolonging the F-16, but the original vision to transfer to an all-stealth fleet before 2030 has been overtaken by events. Capping production of Lockheed F-22s at 187 aircraft has forced the USAF to spend $900 million to equip 176 Boeing F-15Cs with the Raytheon APG-63(V)3 active electronically scanned array radar.

With the Lockheed F-35A's entry into service delayed to at least 2016, the "ageing F-16 fleet may be required to remain in service longer than currently planned", according to an August report by the US Government Accountability Office.

McHenry, however, believes the structural modifications for F-16s were an inevitable step in the transition from fourth-generation fighters to the F-22 and F-35.

"The USAF is coming forth and dispelling the myth that says 'I'm going to get rid of my fourth-generation airplanes tomorrow'," McHenry says. "It's going to take a long period of time to transition to an all fifth-generation fleet."

In a report submitted by the USAF to Congress earlier this year, buying all-new F-16s was practically ruled out. The air force estimated that a service life extension programme of existing F-16s would be cheaper by 80-85%.

The USAF is considering more than structural upgrades for the F-16s. Both Raytheon and Northrop Grumman are offering to retrofit the type with AESA sensors - the Raytheon active combat radar (RACR) and the selectable agile beam radar (SABR).

"They have their opinion of how easy and hard it is to put their AESA in the airplane. Well, we have our own opinion," McHenry says.

If some F-16s are preserved, the USAF also may consider other sensor upgrades, including the integration of an infrared search and track sensor and digital radar warning system. Many of the same upgrades have been approved already for the F-15, but McHenry questions whether preserving more F-16s would save money.

"It makes the most sense to extend the life of the airplane that costs less to operate," he says. "If the aircraft is a bridge to something, you ought to make sure you're bridging with an airplane that's not costing you an arm or leg."

Source: Flight International