WASHINGTON — The U.S. Air Force appears to be breathing new life into its fleet of F-16s, with plans for upgrades and structural work inching forward as the service contemplates whether to replace its F-15C/Ds with the newer, less expensive F-16.

F-16 manufacturer Lockheed Martin announced early Wednesday that the Air Force had authorized service life extension work, which could keep the fighter jets flying past 2048. The service life extension program (SLEP) will encompass lengthening the lifespan of up to 300 F-16C/D Block 40-52 aircraft from 8,000 to 12,000 flight hours.

That means that the Air Force has validated that, with modifications, it can almost double the life of the F-16, Randy Howard, Lockheed's director of F-16 business development, told Defense News. However, the service still needs to make a final decision on when to start the SLEP process, how many planes to modify and whether to rely on organic or contractor-provided labor.

"What would be the next natural step is for the USAF to contract to have the work done that our data indicates needs to be done in order to certify and extend the life of the aircraft," he told Defense News. "That's what lies ahead."

An Air Force spokeswoman said the service will compete the opportunity to SLEP the 300 F-16s, but could not confirm when it will issue a request for proposals to industry.

Several years ago, the Air Force put Lockheed under contract for the beginning stages of the SLEP. During that time the company cycled F-16s through a series of tests that simulated flight hours and put stress on the aircraft, and then figured out which areas of the plane would need structural modification in order to extend the life of the plane, Howard said.

"The structural elements of the aircraft that typically have life-limiting hours to them are wings and bulkheads, those kinds of areas because of the high Gs the airplane [experiences]," he said.

Lockheed believes it may be able to push the aircraft’s lifespan beyond 12,000 hours.

"In our testing, we took the units out beyond 27,000 hours," Howard said. Manufacturers are usually able to certify the aircraft for about half the number of hours that aircraft fly during tests — meaning that there is still room to validate an even longer lifespan. "So there is still some ongoing effort to take our testing and certify the aircraft beyond what this announcement does."

Aside from a potential SLEP, the Air Force is also considering several upgrades to the F-16’s avionics system. Earlier this year, the service chose Raytheon to modernize the aircraft’s mission computers with a new version with added memory and processing power.

Officials also view replacing the F-16’s current radar with an active electronically scanned array (AESA) as key for future operations, particularly if the aircraft replaces the F-15C/D, which was developed for the air superiority mission.

The Air Force’s 416th Flight Test Squadron is continuing developmental tests of one such system, Northrop Grumman’s APG-83 Scalable Agile Beam Radar, or SABR. The service has integrated SABR with F-16s for ground and flight tests, and will use that data to assess whether the radar will meet its operational needs, it said in a March news release.

Lockheed is performing similar F-16 upgrade work for Taiwan, Singapore and South Korea that puts SABR radars and new mission computers into those countries’ jets.