Boeing is speaking out against a controversial proposal by the U.S. Air Force to retire the F-15C Eagle fleet, saying an upgraded Lockheed Martin F-16 is no substitute for its Cold War-era air superiority fighter.
The service has floated the idea of retiring all F-15C squadrons in favor of F-16s equipped with active electronically scanned array radars for the homeland defense mission. This would avoid a major structural service life extension of the F-15C, pegged at $30-40 million per airplane for new wings and a remanufactured center fuselage. Money saved could be spent on the development and production of a future air dominance aircraft, or perhaps free up cash to boost the Lockheed F-35 Lightning II buy rate.
Boeing says the F-16 cannot match the F-15 in terms of speed, range, payload or radar capability, and would make a poor Eagle replacement, even as a short-term stopgap.
Boeing is fatigue testing the Eagle and its air-to-surface attack variant, the F-15E Strike Eagle, at the company’s plant in St. Louis. The results suggest that a relatively simple and inexpensive longeron replacement will keep the F-15 fleet soaring into the mid-2030s and perhaps longer.
The $30-40 million cost cited by the head of Air Combat Command in March represents the total cost of remanufacturing the center fuselage and installing new wings, Boeing says. That cost estimate was provided at the service’s request, it adds.
“That approach, we believe, is the costliest solution and a worst-case scenario; it’s not something we believe is under serious consideration at this time,” Steve Parker, vice president of Boeing F-15 programs, said in an April 17 interview. “That would take it out another 40-50 years.”
Parker says the longerons are already being replaced by the Air Force as the F-15s cycle through programmed depot maintenance. The total cost is $1 million per aircraft for parts and labor.
Boeing says the Eagle is structurally viable out to 15,000 flight hours with this upgrade, allowing the fleet to continue in its current role until the mid-2030s, based on current flying rates.
The Air Force will replace the longerons on all 235 F-15Cs by 2023/24 based on the current timeline. In its fiscal 2017 budget request, the service proposed flying the aircraft through 2045, which would require major structural upgrades, beginning with a full wing replacement in the 2020s.
Parker said “$1 million per aircraft is just the standalone structural modification taking it into the 2030s.”
The F-15 structural modifications are just one aspect of continued F-15 service. The Air Force already has billions of dollars tied up in capability upgrades, many of which are well underway.
The service is most of the way through a major radar upgrade, installing Raytheon’s all-digital APG-63(V)3 active electronically scanned array on the F-15C/D and APG-82(V)1 on the F-15E. The F-15E has already begun flying with the Advanced Display Core Processor II. Meanwhile, BAE Systems’ Eagle Passive Active Warning Survivability System (Epawss) electronic combat suite recently passed the government’s critical design review milestone and will transition to begin flight testing in early 2018.
Boeing says all these pieces will keep the F-15C’s talons sharp well into the 2030s. Retiring the F-15 early would diminish the service’s fighter capacity and capability, the firm says.
The Air Force’s F-15 to F-16 transition proposal is being considered as part of the fiscal 2019 “planning choices” process. It would mostly affect the Air National Guard, but also active-duty squadrons based in the UK and Japan.
“Why would you divest and replace [the F-15C] with an asset that does not have as capable of a radar system, doesn’t have the range, speed and payload and the same ability to protect the homeland?” Parker asks. “If we’re under attack, don’t you want the fastest, quickest platform that can carry more and take the threat out?”
The F-15 was originally meant to be replaced by the Lockheed Martin F-22 Raptor, of which Boeing was a key supplier. But the production run was truncated at 187 operational aircraft and closed in 2011.
The Air Force’s Penetrating Counter-Air/F-X program, which is in the analysis of alternatives phase, is meant to field enough aircraft by the 2030s to allow the 183-aircraft F-22 fleet to assume the Eagle’s homeland defense role. Separately, the service has approved a Lockheed-run service life extension of the F-16C/D, adding 4,000 hr. of additional structural life to 300 select Block 40-52 aircraft, keeping them around until 2048.
Even with the question mark hanging over the F-15C fleet, Boeing is still pitching “2040C Eagle” capability upgrades to the Air Force and potential international customers, such as Qatar.
The 2040C capability suite includes conformal fuel tanks, an infrared search-and-track sensor, a fifth-generation communications gateway, and quad-pack missile racks on weapon stations No. 2 and No. 8, in addition to the electronic warfare, radar and processor improvements.
Boeing says there is strong interest in these capabilities, and it recently signed a contract with the Air National Guard to conduct airworthiness tests of conformal fuel tanks.
The company also is developing the missile racks on its own dime to carry four Raytheon AIM-120 Advanced Medium-Range Air-to-Air Missiles apiece instead of two. Boeing is demonstrating the quad-pack racks for an undisclosed international customer, with flight testing expected this year.
“We’ve seen renewed interest, even with the chitter-chatter about the predicational [retirement plan],” Parker says. “If you’re a nation and you need to defend your sovereignty, you need an air superiority fighter. We have the best, most advanced air superiority fighter currently in production.”
