The Future of America's Eagles Part I

Image 1: USAF F-15C. Image Credit: USAF

This article is a continuation of the future of the USAF article series. USAF plans for the F-15C will be examined.

The F-15 was envisioned to be the ultimate purebred dogfighter with the following as its design emphasis: "not a pound air to ground". The F-15A defined the characteristics of an entire generation of subsequent fighter aircraft: high maneuverability, powerful radar, and large air to air missile load.The first F-15A Eagles were delivered to the USAF nearly forty years ago. Since its deployment, the F-15 has earned a global reputation as one of the most successful fighter designs in history. The F-15 maintains the highest kill ratio of any fighter aircraft in history, 104-0 (Source 1). Despite the development and procurement of 5th generation aircraft like the F-22 and F-35, the venerable fourth generation F-15C will remain in service with the USAF until at least 2030. A core of 176 F-15C's will undergo an extensive $3 billion dollar upgrade program. A series of comprehensive structural upgrades will allow the F-15C's airframes to remain viable until 18,000 flight hours have been reached (Source 2). Other planned upgrades for the F-15C include APG-63(V)3 radar, improved electronic countermeasures, minimal drag infrared search and track (IRST) pod, mode 5 IFF, Advanced Display Core Processor (ADCP) II, improved data link capability, improved data sharing, satellite communications (SATCOM) radio, and Sniper targeting pod integration (Source 3 & 4). These upgrades and the added capabilities will be discussed in this article (Part I). Following the discussion of these upgrades, the important role of the F-15C will be discussed in regards to America's pivot to the Pacific (Part II).

UPGRADES 

Structural 

Image 2: Planned structural upgrade program during  programmed depot maintenance (PDM). Image credit: Major Richard Van Slyke & Russell Ewan (Source 6).   

The USAF plans to add an additional 6,000 service hours to the 12,000 hour rated F-15C airframe. These upgrades are desperately need if the USAF realistically desires to continually operate the F-15C past its original 9,000 service hour certification. Boeing will extend the life of 176 F-15C's as demonstrated by the image above. Areas of the airframe that tend to experience high structural stress, such as the wing, will be either replaced or strengthened to insure structural integrity during high g maneuvers. Structural fatigue testing of the new components should be completed by 2014 (Source 12). 

Radar

Image 3: AN/APG-63(V)3 radar. Image credit: Ratheyon

The AN/APG-63(V)3 is a 1,500 element actively scanned electronic array (AESA). The APG-63(V)3 represents a significant increase in capabilities for the F-15C. Added benefits from the APG-63(V)3 include: greatly increased maximum detection range, improved reliability over previous generation electronically scanned arrays (ESA), improved target tracking, and electronic warfare capabilities (Source 4). The addition of an AESA array will also keep the F-15C competitive against the newer generation of Russian Flanker designs which feature either a highly upgraded ESA radar or an AESA radar. Furthermore, the addition of the APG-63(V)3 will greatly aid Eagle pilots detect low observable targets such as the J-20 (Source 4). The USAF plans to equip 150 Eagles with the APG-63(V)3 (Source 20).

Although the F-15C is set to receive a number of sensor and radar upgrades, the Cold War era cockpit remains an issue for pilots. Dave Munjumar reported that F-15 pilots will not be able to take full advantage of their new avionics with their old cockpit interface (shown below).

"You have these phenomenal subsystems, but if you can't provide [sensor data] in a meaningful way to the operator, it doesn't matter." - former Eagle pilot, source 2

The 53rd Test and Evaluation Group is currently testing the addition of two modern liquid crystal displays in the F-15 cockpit. These changes are sorely needed (e.g. current radar display is a four by four inch screen). 

IRST

Image 5: F-15C with Lockheed Martin SpectIR pod mounted on station 5. Image retrieved via Defense Industry Daily

The USAF plans to acquire 100 IRST pods for its F-15C fleet beginning in 2015. The new IRST pod for the F-15C will likely be an evolved form of the Lockheed Martin built Tiger Eyes IRST system supplied to Korean F-15K's. The SpectIR pod shown above is an Lockheed financed development project to fulfill the USAF's F-15C IRST requirement. The SpectIR pod is also compatible with the F-16 and F-18 (Source 17). Despite its placement on the lower fuselage, the SpectIR pod is capable of looking up 5 degrees.

The addition of a low drag IRST system to the F-15 is vital. As I've mentioned before, both the Russian and Chinese stealth fighter designs lack IR signature reduction engine nozzles. The inclusion of  SpectIR will aid Eagle pilots in visual range engagements with 5th generation opponents. The Eagle is already capable of employing off-boresight missiles (e.g. AIM-9X) and features the Joint Helmet Mounted Cueing System (JHMCS). Furthermore  the addition of an IRST will also aid the F-15 detect incoming missile threats.

Eagle Passive/Active Warning and Survivability System (EPAWSS)

The Northrup Grumman built Eagle/Passive Active Warning and Survivability System (EPAWSS) grants the Eagle significantly increased survivability against missile threats. Without stealth, Eagle pilots will have to rely upon EPAWSS in conjunction with traditional missile defeating maneuvers to survive in a high threat environment. Before the inclusion of EPAWSS, the  F-15 electronic counter measure system was comprised of three 1980s era systems.

"The aircraft now rely on three ageing systems for self-defence - the ALR-56C radar warning receiver, ALQ-135 jammer and ALE-45 countermeasures dispenser." - Stephen Trimble

EPAWSS requirements can be found here.

Continue to Part II 

Sources

1. http://www.airforce-magazine.com/MagazineArchive/Pages/2008/February%202008/0208reformers.aspx  
2. http://www.flightglobal.com/news/articles/usaf-plans-f-15-modernization-but-pilots-want-better-displays-375612/ 
3. http://www.airforcetimes.com/news/2012/10/air-force-f-15-upgrades-aim-double-service-life-102912w/ 
4. http://www.flightglobal.com/news/articles/usaf-may-convert-some-f-15cs-to-radar-jammers-340532/
5. http://www.wrcoc-aic.org/archive/rs/rs09/rs09_03.pdf 
6. http://www.rand.org/pubs/technical_reports/TR528.html 
7. https://www.fbo.gov/index?s=opportunity&mode=form&id=578b5e3200c1a48922a9449c15a3bc25&tab=core&_cview=0
8. http://www.airforce-technology.com/news/newsusaf-likely-to-modernise-its-f-15c-and-f-15e-fleets
9. http://www.defenseindustrydaily.com/singapores-rsaf-decides-to-fly-like-an-eagle-01141/
10. http://www.flightglobal.com/news/articles/usaf-investigating-new-displays-for-f-15c-eagle-383308/
11. http://www.flightglobal.com/blogs/the-dewline/2011/11/32000-hour-f-15.html 
12. https://www.fbo.gov/index?s=opportunity&mode=form&id=adf7dcdf27ab12fb1780405de8fa2f8f&tab=core&_cview=1
13. http://www.northropgrumman.com/Capabilities/EPAWSS/Pages/default.aspx
14. http://www.dtic.mil/descriptivesum/Y2013/AirForce/stamped/0207134F_7_PB_2013.pdf
15. http://www.lockheedmartin.com/us/products/InfraredSearchTrack.html
16. http://www.defenseindustrydaily.com/f-18-super-hornets-to-get-irst-03429/
17. http://www.flightglobal.com/news/articles/usaf-adds-irst-pod-for-f-15s-332380/
18. http://www.defensemedianetwork.com/stories/f-15cd-eagle-upgrades-are-a-moving-target/
19. http://www.af.mil/news/story.asp?id=123290989

Image 6: F-15C from the 493rd Expeditionary Fighter Squadron. Image Credit: USAF