Through Upgrades, Boeing Envisions Longer Utility of the F-15
The U.S. Air Force plans to fly the F-15E Strike Eagle into the 2040s, but the F-15C/D air superiority fighter faces a shorter time horizon.
Replacing longerons on the F-15C would extend its service life into the mid-2030s, Boeing contends. (Photo: U.S. Air Force)

F-15 production is secure through 2019, and planned updates will keep the U.S. Air Force flying the multi-role F-15E Strike Eagle version into the 2040s, Boeing reports. The manufacturer also has a case to make for extending the life of the F-15C/D air superiority version of the 1970s-vintage fighter, which faces a shorter time horizon.

“The last time we delivered a Strike Eagle to the U.S. Air Force was in the mid-2000s,” Steve Parker, Boeing vice president for F-15 programs, told reporters visiting the company’s St. Louis-area manufacturing facility May 17. “Right now, over the last couple-year period, is the most amount of budget that has been allocated to the F-15 for some time—in excess of $12 billion of upgrades the U.S. Air Force is funding to take this platform into the 2040s and beyond.”

The Air Force is installing active electronically scanned array (AESA) radar on both versions of the fighter—Raytheon’s APG-63(V)3 for the F-15C and APG-82(V)1 for the F-15E. Parker said more than 125 of 200 F-15Cs have already been modified; retrofit of the F-15Es will continue into the 2020s.

According to an Air Force budget document, the service is seeking $963 million for the F-15 program in Fiscal Year 2018, which would continue the radar upgrades and development of the Eagle Passive/Active Warning Survivability System (EPAWSS) to improve the F-15E’s ability to detect and defeat air and ground threats. The service awarded Boeing a $478.7 million engineering and manufacturing development (EMD) contract for EPAWSS in November, and Boeing completed a critical design review of the electronic warfare (EW) suite in February this year, according to supplier BAE Systems. The EMD contract calls for work to be completed by Aug. 31, 2020.

The introduction of an Advanced Display Core Processor II (ADCPII) mission computer with multi-core processing capability “unleashes the horsepower” of EPAWSS, an EW system that takes proven technology into “the fifth-gen domain,” Parker said. Boeing is modifying a fighter this year to begin flight tests with the system in 2018, followed by deployment in the early 2020s, he reported.

Boeing recently completed a fly-off of competing infrared search-and-track (IRST) pods that it will integrate on the F-15C/D—Lockheed Martin and Northrop Grumman are the possible suppliers—and planned to select one system within months, Parker said.

Testifying before the House Armed Services Committee on March 22, however, senior Air Force and Air National Guard officers suggested the days may be numbered for the F-15C/D.

Lt. Gen. Scott Rice, director of the Air National Guard, did not disagree when asked if the F-15 will be replaced by the Lockheed Martin F-16 in the air superiority role. Guard squadrons fly F-15s for the aerospace control alert mission in defense of the homeland. “There are capabilities we can add and provide on the F-16 that will provide us a gap as we try to go into the future. Overall our readiness and then our protection of the U.S. will change but I think overall we will be OK,” he said.

Maj. Gen. Scott West, Air Force deputy chief of staff for operations, said the service must make choices based on its budgetary authority. “The F-15C has served the nation well as have its pilots, for decades. It was our air superiority fighter; now F-22 has taken that role,” West said. “We do have capacity in the F-16C community to recapitalize it with an improved radar to serve the same function as the F-15 has done and thereby reduce the different systems that we have to sustain and operate…so that we can make other choices either for modernization or (to) grow end strength.”

At a hearing before the Senate Armed Services Committee a week later, the Air Force walked back the idea of retiring the F-15C/D fleet. “That’s pre-decisional,” said Lt. Gen. Jerry Harris, Air Force deputy chief of staff for strategic plans, programs and requirements, responding to questions from Sen. Elizabeth Warren (D-Mass.). “We have not decided, and throughout our FYDP [Future Years Defense Program] we continue to employ the F-15C/D fleet. It’s an air superiority fighter for us, with somewhat limited capabilities from a fourth-gen perspective compared to an F-22. But we are not replacing it at this time; it is something that we are looking at as we continue to bring in more fifth-gen capability—what assets do we push out at the bottom of that chain?”

In written testimony to the Senate committee, the Air Force said it “expects the F-15E to be an integral part (of the fleet) through at least 2040,” along with the F-16.

Boeing argues that F-15C/Ds have a service life of up to 15,000 hours and could serve into the mid-2030s by replacing longitudinal spars, or longerons, along their fuselages at a cost of $1 million per aircraft. “I have the only air superiority aircraft in production in the U.S. today—that is undisputable,” Parker said. “I’m running at 1.25 aircraft a month; I have the capacity to increase that. I have plans that would enable me to do that if the customer demand was there.”

Meanwhile, Boeing has a “good, solid backlog” of F-15 orders from international customers. The F-15s it is delivering today have service lives exceeding 20,000 hours stemming from wing and fuselage redesigns over the last several years, as well as new technologies that buyers have introduced, Parker said.

New multi-role F-15SAs Saudi Arabia has ordered come with fly-by-wire flight controls. Boeing started delivering F-15SAs to the kingdom last December, and now a “double digit” number of fighters have arrived in-country, Parker said. Saudi Arabia is due to receive 84 F-15SAs and 70 upgraded fighters from a $29.4 billion arms agreement the countries negotiated in 2010-2011. Deliveries will be completed over the next three years.

Boeing will complete deliveries this year for another foreign customer that Parker declined to identify, but that AIN understands is Singapore. Another possible buyer is Qatar. The U.S. State Department approved the foreign military sale to that nation of 72 F-15QA multi-role fighters—an estimated $21 billion transaction—according to a Defense Security Cooperation Agency notification to Congress in November.