Editing McDonnell Douglas F-15 Eagle (section)

===Upgrades and further development===
{{main|McDonnell Douglas F-15E Strike Eagle|Boeing F-15EX Eagle II}}
[[File:F-15, 71st Fighter Squadron, in flight.JPG|thumb|USAF F-15C during [[Operation Noble Eagle]] patrol, 2007]]
The single-seat F-15C and two-seat F-15D models entered production in 1978 and conducted their first flights in February and June of that year.<ref name=Jenkins_p33-4>Jenkins 1998, pp. 33–34.</ref> These models were fitted with the Production Eagle Package (PEP 2000), which included {{convert|2000|lb|kg}} of additional internal fuel, provisions for exterior [[conformal fuel tank]]s (CFT), and an increased maximum takeoff weight up to {{convert|68000|lb|kg}}.<ref name=green /> The increased takeoff weight allows internal fuel, a full weapons load, conformal fuel tanks, and three external fuel tanks to be carried. The [[APG-63]] radar uses a programmable signal processor (PSP), enabling the radar to be reprogrammable for additional purposes such as the addition of new armaments and equipment. The PSP was the first of its kind in the world, and the upgraded APG-63 radar was the first radar to use it. Other improvements included strengthened landing gear, a new digital central computer,<ref>Davies and Dildy 2007, p. 115.</ref> and an overload warning system (OWS), which allows the pilot to fly up to 9&nbsp;''g'' at all weights.<ref name=Jenkins_p33-4 />

The F-15 Multistage Improvement Program (MSIP) was initiated in February 1983 with the first production MSIP F-15C produced in 1985. Improvements included an upgraded central computer; a Programmable Armament Control Set, allowing for advanced versions of the [[AIM-7]], [[AIM-9]], and [[AIM-120A]] missiles; and an expanded Tactical Electronic Warfare System that provides improvements to the ALR-56C radar warning receiver and [[AN/ALQ-135|ALQ-135]] countermeasure set. The final 43 F-15Cs included the Hughes [[APG-70]] radar developed for the F-15E (see below); these are sometimes referred as Enhanced Eagles. Earlier MSIP F-15Cs with the APG-63 were upgraded to the [[APG-63(V)2|APG-63(V)1]] to improve maintainability and to perform similar to the APG-70. Existing F-15s were [[retrofitted]] with these improvements. Also beginning in 1985, F-15C and D models were equipped with the improved P&W F100-PW-220 engine and digital engine controls, providing quicker throttle response, reduced wear, and lower fuel consumption. Starting in 1997, original F100-PW-100 engines were upgraded to a similar configuration with the designation F100-PW-220E starting.<ref>Davies and Dildy 2007, pp. 168–69.</ref> In 2000, the [[APG-63(V)2]] [[active electronically scanned array]] (AESA) radar was retrofitted to 18 U.S. Air Force F-15C aircraft.<ref>[https://www.fas.org/man/dod-101/sys/ac/docs/n19991208_992202.htm "18 APG-63(V)2."] {{Webarchive |url=https://web.archive.org/web/20201112025711/https://fas.org/man/dod-101/sys/ac/docs/n19991208_992202.htm |date=12 November 2020}} ''Fas.org'', 8 December 1999. Retrieved: 30 December 2010.</ref> The ZAP (Zone Acquisition Program) missile launch envelope has been integrated into the operational flight program system of all U.S. F-15 aircraft, providing dynamic launch zone and launch acceptability region information for missiles to the pilot by display cues in real-time.<ref>{{cite web |title=ZAP Missile Launch Envelope |url=https://www.faac.com/training-simulators/military/air/zap-missile-launch-envelope/ |website=faac.com |publisher=FAAC / Arotech |access-date=18 November 2019 |date=14 March 2017 |archive-date=27 September 2020 |archive-url=https://web.archive.org/web/20200927083646/https://www.faac.com/training-simulators/military/air/zap-missile-launch-envelope/ |url-status=live}}</ref>

[[File:F-15E with the speed brake up.jpg|thumb|upright|F-15E with [[Air brake (aircraft)|speed brake]] deployed and CFTs fitted]]
Although the Air Force's F-X requirements were focused on air superiority, McDonnell Douglas had quietly included a basic secondary ground attack capability in the F-15's design since the beginning and also performed early internal studies for enhancing that capability.<ref>[https://www.scribd.com/doc/94122923/PS-940-F-15-Armament-Handbook-Oct-1979 "PS 940 F-15 Armament Handbook, Oct-1979."] {{Webarchive |url=https://web.archive.org/web/20140111061705/http://www.scribd.com/doc/94122923/PS-940-F-15-Armament-Handbook-Oct-1979 |date=11 January 2014}} ''scribd.com.'' Retrieved: 29 November 2012.</ref> In 1979, McDonnell Douglas and F-15 radar manufacturer, [[Hughes Aircraft|Hughes]], teamed to privately develop a [[strike fighter]] version of the F-15. This version competed in the Air Force's [[Enhanced Tactical Fighter|Dual-Role Fighter]] competition starting in 1982. The [[McDonnell Douglas F-15E Strike Eagle|F-15E]] strike variant was selected for production over General Dynamics' competing [[F-16XL]] in 1984; it is a two-seat, dual-role, totally integrated fighter for all-weather, air-to-air, and deep [[air interdiction|interdiction]] missions.<ref>Davies 2003, pp. 15–16, 25, 31–32.</ref> The rear cockpit is upgraded to include four multipurpose [[cathode-ray tube]] displays for aircraft systems and weapons management. The digital, triple-redundant [[EG&G|Lear Siegler]] [[aircraft flight control system]] permits coupled [[Terrain-following radar|automatic terrain following]], enhanced by a [[ring laser gyroscope|ring-laser gyro]] inertial navigation system.<ref>Lambert 1993, p. 523.</ref> For low-altitude, high-speed penetration and precision attack on tactical targets at night or in adverse weather, the F-15E carries a high-resolution [[AN/APG-63 radar family|APG-70]] radar and [[LANTIRN]] pods to provide [[thermography]].<ref name=Jenkins_p97 /> The F-15E would be developed into the [[McDonnell Douglas F-15E Strike Eagle#F-15 Advanced Eagle variants|F-15 Advanced Eagle]] family, which features [[fly-by-wire]] controls; the Advanced Eagle is currently the basis of all current F-15 production.<ref name="janes.com">{{cite web |title=Qatar agrees purchase of F-15QA fighters from US |url=http://www.janes.com/article/71443/qatar-agrees-purchase-of-f-15qa-fighters-from-us |author=Gareth Jennings |date=15 June 2017 |publisher=Jane's |archive-url=https://web.archive.org/web/20170615102902/http://www.janes.com/article/71443/qatar-agrees-purchase-of-f-15qa-fighters-from-us |archive-date=15 June 2017 |url-status=dead}}</ref>

[[File:AN-APG-63V3.jpg|thumb|left|AN/APG-63(V)3]]
Beginning in 2006, with the threat of curtailed procurement of the [[Lockheed Martin F-22 Raptor|F-22]] that was to replace all air superiority F-15s, USAF planned to modernize 179 F-15Cs in the best material condition in order to maintain fighter fleet size by retrofitting the [[APG-63 and APG-70 radars|AN/APG-63(V)3]] AESA radar and updated cockpit displays; the first upgraded aircraft was delivered in October 2010.<ref>Davies and Dildy 2007, pp. 161–65.</ref><ref name=Upgrade_radar>[https://combataircraft.keypublishing.com/2018/07/19/new-usaf-f-15c-radar-upgrades/ "New USAF F-15C Radar Upgrades."] {{Webarchive |url=https://web.archive.org/web/20230313154842/https://www.key.aero/ |date=13 March 2023}} ''Combat Aircraft'', Key Publishing, 19 July 2018. Retrieved: 14 March 2019.</ref> A significant number of F-15s were equipped with the [[Joint Helmet Mounted Cueing System]].<ref name=F-15_upgrades_2006>[https://www.spacewar.com/reports/Air_Force_Will_Get_New_Bomber_Upgrades_To_Fighters_999.html "Air Force will get new bomber, upgrades to fighters."] {{Webarchive |url=https://web.archive.org/web/20190804154116/http://www.spacewar.com/reports/Air_Force_Will_Get_New_Bomber_Upgrades_To_Fighters_999.html |date=4 August 2019}} ''Spacewar.com'', 5 October 2006. Retrieved: 1 September 2011.</ref> Lockheed Martin developed an [[infrared search and track]] (IRST) sensor system for tactical fighters such the F-15C, eventually resulting in the AN/ASG-34(V)1 IRST21 sensor mounted in the Legion Pod; the AN/AAQ-33 Sniper XR pod was also integrated as a makeshift interim IRST solution.<ref>[http://www.lockheedmartin.com/news/press_releases/2010/MFC_042810_LM_DevelopingF-15C_IRST.html "Lockheed Martin Developing System Requirements for F-15C IRST Program."] {{Webarchive |url=https://web.archive.org/web/20100504214359/http://www.lockheedmartin.com/news/press_releases/2010/MFC_042810_LM_DevelopingF-15C_IRST.html |date=4 May 2010}} ''Lockheed Martin.'' Retrieved: 30 December 2010</ref> A follow-on upgrade called the Eagle Passive/Active Warning Survivability System (EPAWSS) was planned.<ref>Trimble, Stephen. [https://www.flightglobal.com/news/articles/us-air-force-looks-to-dramatically-extend-f-15-service-life-365200/ "US Air Force looks to dramatically extend F-15 service life."] {{Webarchive |url=https://web.archive.org/web/20190816184720/https://www.flightglobal.com/news/articles/us-air-force-looks-to-dramatically-extend-f-15-service-life-365200/ |date=16 August 2019}} ''Flightglobal'', 23 November 2011.</ref> Boeing was selected in October 2015 to serve as prime contractor for the EPAWSS, with [[BAE Systems]] selected as a subcontractor. The EPAWSS is an all-digital system with advanced electronic countermeasures, radar warning, and increased chaff and flare capabilities in a smaller footprint than the 1980s-era Tactical Electronic Warfare System. More than 400 F-15Cs and F-15Es were planned to have the system installed.<ref>[https://www.ainonline.com/aviation-news/defense/2015-10-01/boeing-bae-develop-new-electronic-warfare-suite-f-15 Boeing, BAE To Develop New Electronic Warfare Suite for F-15] {{Webarchive |url=https://web.archive.org/web/20200420225524/https://www.ainonline.com/aviation-news/defense/2015-10-01/boeing-bae-develop-new-electronic-warfare-suite-f-15 |date=20 April 2020}} – Ainonline.com, 1 October 2015</ref>

In September 2015, Boeing unveiled its 2040C Eagle upgrade (also called "Golden Eagle"), designed to keep the F-15 relevant through 2040. Seen as a necessity because of the low numbers of F-22s procured, the upgrade builds upon the company's [[F-15SE Silent Eagle]] concept with low-observable features. Most improvements focus on lethality including quad-pack munitions racks to double its missile load to 16, [[conformal fuel tank]]s for extended range, "[[Talon HATE]]" communications pod to communicate with fifth-generation fighters, the APG-63(V)3 AESA radar, long-range Legion IRST pod, and EPAWSS electronic warfare suite.<ref>[https://www.flightglobal.com/news/articles/boeing-doubles-f-15c-missile-load-in-2040c-eagle-u-416766/ Boeing doubles F-15C missile load in '2040C' Eagle upgrade] {{Webarchive |url=https://web.archive.org/web/20150917080521/https://www.flightglobal.com/news/articles/boeing-doubles-f-15c-missile-load-in-2040c-eagle-u-416766/ |date=17 September 2015}} – Flightglobal.com, 15 September 2015</ref><ref>{{cite news |url=https://boeing.mediaroom.com/2014-09-16-Boeing-Completes-Design-Review-for-U-S-Air-Force-s-Talon-HATE-Program |title=Boeing Completes Design Review for U.S. Air Force's Talon HATE Program |last1=Sampson |first1=Cheryl |date=16 September 2016 |website=mediaroom.com |publisher=Boeing |access-date=31 December 2015 |archive-date=13 December 2015 |archive-url=https://web.archive.org/web/20151213013314/http://boeing.mediaroom.com/2014-09-16-Boeing-Completes-Design-Review-for-U-S-Air-Force-s-Talon-HATE-Program |url-status=live}}</ref><ref>{{cite web|url=https://boeing.mediaroom.com/2015-10-01-Boeing-Selected-as-Prime-for-EPAWSS-Electronic-Warfare-Suite-Program|title=News Releases/Statements|website=MediaRoom|access-date=26 June 2017|archive-date=30 June 2017|archive-url=https://web.archive.org/web/20170630111502/http://boeing.mediaroom.com/2015-10-01-Boeing-Selected-as-Prime-for-EPAWSS-Electronic-Warfare-Suite-Program|url-status=live}}</ref><ref>{{cite web|url=https://www.baesystems.com/en-us/article/boeing-selects-bae-systems-to-develop-new-electronic-warfare-system-for-u-s--air-force-s-f-15-fighter-aircraft|title=Boeing selects new EPAWSS system for U.S. Air Force Fighter Aircraft|website=BAE Systems – United States|access-date=26 June 2017|archive-date=30 August 2017|archive-url=https://web.archive.org/web/20170830102303/http://www.baesystems.com/en-us/article/boeing-selects-bae-systems-to-develop-new-electronic-warfare-system-for-u-s--air-force-s-f-15-fighter-aircraft|url-status=live}}</ref> The 2040C upgrade for the F-15C/D was not pursued, owing to the airframes' age that made it not economically sustainable, but many of the components such as EPAWSS and AESA radar were continued for F-15E upgrades as well as new-build [[F-15EX Eagle II]] ordered by USAF in 2020; the F-15EX took advantage of existing Advanced Eagle production line for export customers to minimize lead times and start-up costs to replace the remaining F-15C/Ds, whereas F-22 production restart was considered cost-prohibitive.<ref name="F15EX_selection"/>