The U.S. Air Force is pushing to more than double the life of its stalwart F-15 Eagles with a series of upgrades.

“About two and a half years ago, the U.S. Air Force wanted fatigue tests on C models,” says Brad Jones, F-15 mission systems director for Boeing, which makes the aircraft.

As the F-15 fleet aircraft approached their life expectancies for total flight hours, the Air Force wanted see how far the service could delay fleet retirements, Jones said during a recent briefing with reporters.

The design service life for the aircraft is 8,000 flight hours and the lead-the-fleet aircraft have flown more than 10,000 actual flight hours and counting, Boeing says.

Boeing is now working on full-scale fatigue test certifications to push F-15C/D models to 18,000 equivalent flight hours (EFHs) and F-15E models to 32,000 EHFs. “Structural fatigue improvements in current-production F-15s provide longer life and reduced maintenance requirements,” Boeing says.

“We do not have an end date for the F-15,” Jones says. Indeed, he says, there are several programs to make U.S. and international models better with age.

The F-15 radar modernization program proposes to retrofit all F-15Es by 2021 with APG-82(V)1 suites with APG-79 processors, which will offer a fivefold improvement over the APG-63(V)3 equipment in reliability and effectiveness. The initial operational capability for the radar work is early 2014.

The Advanced Display/Core Processor II (ADCP II) program will replace all the computers in U.S. F-15Es and serve as the baseline computer for all future aircraft sales. The new computers increase computing power, adding additional gigabit Ethernet and fiber channel connections, with a Milestone B decision scheduled in November. “The U.S. Air Force has a display upgrade working team up now,” Jones says.

Boeing also is offering an advanced cockpit system that includes a large-area display, low-profile head-up display, reference standby display and low-profile engine fuel hydraulics display, all of which replace 23 existing displays, instruments and indicators.

“It’s more for situational awareness,” Jones says, adding the improvements significantly lower the cost of the aircraft, for both purchase price and life cycle costs.

The proposed new Digital Electronic Warfare System (DEWS) replaces several legacy systems, such as the radar warning receiver, jammer internal countermeasures set, countermeasures dispenser and interface blanker.

With DEWS, there is no need for a waveguide or nitrogen pressurization, Boeing says, and the digital system provides more than 200% throughput and memory growth reserve as well as better operation with wideband agile radars and other RF systems.