An extended flight-hour limit for F-16C Block 50 aircraft is to be determined by Lockheed Martin with data gathered through simulated flights.

The data will help determine the durability of the aircraft beyond the original design service life of 8,000 hours, the company reported.

So far, 27,713 equivalent flight hours have been logged by a test aircraft during 32 rounds of comprehensive stress tests and its airframe subjected to several maximum-load conditions to demonstrate if the airframe had sufficient strength to operate within its full operational flight envelope.

Lockheed said the F-16 is now in the teardown inspection and fractography phase of the test program at the company's Full Scale Durability Test facility in Fort Worth. Durability test results will be used to help design and verify Service Life Extension Program, or SLEP, structural modifications.

The modifications will be for post-Block 40 F-16s and will also support F-16 service life certification to at least 12,000 extended flying hours.

"The successful completion of this phase of full-scale durability testing demonstrates that this aircraft was built to last," said Susan Ouzts, vice president of Lockheed Martin's F-16 program. "This should provide even more confidence to current and potential new F-16 customers that the combat-proven F-16 will continue to play a crucial role in international security."