USA (1976)
Tactical Fighter – 1,600 Built
The F-15 Eagle is beyond any doubt one of the most famous air superiority fighters of the second half of the Cold War, and a worthy successor of the also famous McDonnel Douglas F-4 Phantom. For instance, its predecessor was designed to be a fighter with attack capabilities for any weather condition, and the same concept was taken into account when developing the Eagle, only that it was intended mainly for air superiority. Interestingly, and despite the F-4 being a naval plane for most of the part, the F-15 would be a combat eagle on use by the USAF. There is also another thing both planes have in common, despite being the Phantom already in combat and the Eagle yet to be developed: the Vietnam War. As it happens, high number of casualties made the US Navy and the Air Force, along with the influence of Secretary of State Robert McNamara, to look for new models to replace the existing ones, including the Phantom. The introduction of the Mig 25 Foxbat provided the final argument in favour of the development of a new aircraft for air superiority. And with while the Navy would ultimately incorporate the Grumman F-14 Tomcat, the USAF decided to go for its own fighter, resulting in the F-15, being the counterpart of the Tomcat and taking the Mig-25 as inspiration in terms of performance, to say the least.
The F-15 Eagle is single-seat – or double seat in tandem in certain versions – twin-engine all-weather tactical fighter/air superiority fighter with attack and bombing capabilities, with cantilever shoulder-mounted wings. As it was briefly mentioned, the Vietnam War gave way for its requirement given the high losses to soviet-made aircraft (often old models) back in 1964, with 1968 being the year of requirements issuing and 1969 the year when development of the Eagle began. The main requirement was for the new fighter to be of air superiority and having secondary attack capacities. McDonnell Douglas was the company that awarded the requirements, thus developing the Eagle from the abovementioned year and flying the first prototype in 1972. NASA, in addition, came to take active part in the development of the F-15, especially on its mission requirements, at the same time of the development by the industry contractors.
The Eagle became to be one of the most advanced fighters of the times, clearly fulfilling its mission as it is considered the best air superiority fighter. The secret of its effectiveness and resilience lies on its structure, which is made of metal and then titanium at most of its components, and the empennage made of composite materials – twin aluminium/composite material honeycomb – and the vertical stabilizers made of boron-composite skin. This allowed the tails and the rudders to be very thin yet resistant. The wing also plays its role in bestowing the flying and combat capabilities of the F-15, as this has a cropped delta shape with a leading-edge sweepback of 45 degrees. There are no leading-edge flaps, and the trailing edge – or posterior area of the wing – is having ailerons and a simple high-lift flap. As a result, the wing’ low loading allows the F-15 to be very manoeuvrable without sacrificing speed in the process. The powerplant (two Pratt & Whitney F100-PW-100 turbofans engines with afterburners) and the avionics also play a role in providing the F-15 with its exceptional qualities: The former by bestowing speeds of up to 2.5 Mach and a good time/altitude ratio, the latter by allowing the crew to track and engage targets at distanced up to 160 km (87 miles) and targets at very low and high altitudes.
The F-15 has proven to be a platform capable of receiving structural and avionics/electronics improvements, further enhancing its combat and flight capabilities, with new radars, computers, weapons controls and armament type, powerplants (Pratt & Whitney F-100-PW-220), warning and navigation systems. The F-15 could even receive low visibility technologies, proving the adaptability and capacity of the aircraft to incorporate the latest technologies, as it is the case of the proposed F-15SE Silent Eagle, where its weapons carrying capabilities are proposed to be equally upgraded. This version could co-operate with 5th generation air assets, let alone to almost operate like one.
The F-15 has witnessed action not only in the air campaigns waged by the USA in the Middle East, the Balkans and Central Asia, but also with other air forces, being the Israeli Air Force where the F-15 have had similar combat intensity, and the Saudi Air Force making some considerable use of their F-15s. With the USAF, the F-15 on its different configurations achieved air superiority by shooting down many air assets of Iraq in air-to-air combats or in the ground, as well as to inflict a serious damage to Iraqi military and governmental infrastructure, contributing at a great extend to the sound victory of the Coalition in 1991. The F-15 even managed to destroy a low flying helicopter with a laser guided bomb. The F-15 kept a watch in enforcing the established no-fly zones after this conflict. The Balkans were another scenario where the F-15s made their presence to be felt, by pounding Serbian ground targets and even scoring 4 enemy kills (Serbian Mig-29s). The Second Iraq War, Afghanistan and strikes against ISIS saw the F-15E mainly in action, attacking important targets on these three scenarios, and even providing Close Air Support (CAS) for the troops in the ground.
With the Israeli Air Force, it achieved its first air-to-air kill, establishing then Israeli air superiority over the skies of Lebanon and against Syrian air assets. It had seen use also as a long-range striker and as a platform for attacking specific targets. Saudi Arabia also had some air kills in the 80’s and during Operation Desert Storm, using the F-15s nowadays to strike important targets in Yemen.
As of now, the F-15 is still in service and production (by Boeing, as McDonnell Douglas was absorbed by this company), with the USAF considering to operate with this fighter until 2025 or 2040 at the latest, and production to be maintained until 2019. So far, 1074 units have been produced (by 2012).
Design
The F-15 is an all metal (later on aluminium) semi-monocoque fighter with a shoulder-mounted wing, powered by two engines: 2 Pratt & Whitney F-100-PW-100 (F-15A, F-15B and F-15C) or F-100-PW-220 (F-15DJ and F-15 J), or F-100-PW-229 (F-15E). Two engine air intakes are located at each side of the fuselage, starting from the half area of the cockpit with a intake ramp configuration. The wings have a characteristic shape of a cropped delta shape with a leading-edge sweptback of 45 degrees, starting at nearly half of the wing. It lacks of manoeuvring flaps at the leading edge, having only a simple high-lift flap and ailerons at the trailing edge. As the wing has a low loading with high thrust-to-weight ratio, the F-15 can perform tight turns without any loose of speed, capable also of sustaining high G forces. Noteworthy to point out that the airfoil thickness has a variation of 6% at the wing root, to 3% at the wingtip. The empennage is made out of metal, with the two vertical stabilizers made out of honeycomb twin aluminium and composite materials covered with boron-composite skin, allowing them to be thin but very resisting. This means that the F-15 has two tails, the same way as the Grumman F-14 and the Mig 25. The horizontal stabilizers also have a remarkable characteristic of their own, as they have dogtooth within their structural shape, being able to move independently thus increasing control. The aerodynamic brake is located on the top of the fighter’s structure, behind the cockpit. The landing gear is a retractable tricycle. Noteworthy to point out that the F-15E lack of the typical exhaust petals covering the engine nozzles.
The cockpit is placed high in the frontal part of the aircraft, featuring a one-piece windscreen and a large canopy, allowing a full 360 degrees visibility for the pilot. In most F-15 variants the canopy is designed for one pilot. However, the F-15B, F-15D, F-15DJ and F-15E have a canopy designed for a crew of two: a pilot and a weapons officer in the case of the F-15E, and the student and instructor in the case of the training versions.
The wings and the same structure of the fighter allows it to carry a large number of weaponry and other devices. Among the weaponry normally carried by the F-15, there are AIM-7F/M Sparrow, AIM-120 AMRAAM, AIM—9L/M Sidewinder, as well as the M61 Vulcan Gatling gun at the right wing root. Other armament the F-15 is usually armed with are a varied array of free-fall and directed bombs, rockets, air-ground or anti-ship missiles, such as the AGM-84K SLAM-ER, AGM-84H Harpoon Block II anti-ship missiles, AGM-158 Joint Air-to-Surface Standoff Missile JASSM, AGM-88 HARM anti-radar missiles, and AGM-154 JSOW missiles. ECM pods, external fuel tanks and low-drag conformal fuel tanks (CTFs), which are attached to the sides of the air intakes and cannot be dropped, are usually among the additional equipment carried by this fighter.
The avionics of the F-15 allow an optimal operationalization of the armament carried by this fighter, as well as its navigation and combat-electronic performance and multi-mission capabilities. Among the avionics of the F-15, it could be accounted: Heads Up Display (HUD), the advanced pulse-Doppler Raytheon radars APG-63 and APG-70, the AN/ASN-109 Inertial Guidance System, the Joint Helmet Mounted Cueing System (JHMCS), ECM pods, Hazeltine AN/APX-76 or Raytheon AN/APX-119 IFF device, Magnavox AN/ALQ-128 Electronic Warfare Warning Set (EWWS), Loral AN/ALR-56 radar warning receiver and a Northrop-Grumman Electronics System ALQ-135 internal counter-measures system. All of these comprise the electronic brain of the fighter, which in combination with the powerplant, the aerodynamics and the weapons systems, makes of the F-15 an outstanding air asset that can achieve supreme control over the skies it operates.
As the design of the F-15 allows adaptation and upgrades, all of the versions were receiving gradual upgrades in avionics and engines, being the F-15E the most prominent. Yet some versions operated by other air forces, such as the Israel Air Force and the Republic of Korea Air Force can receive electronic and avionics components developed by those nations, proving that the Eagle is entirely adaptable to receive technology other than of its country of origin. And its versatility allows combat conversions, explaining why a single airframe can have air superiority, attack or electronic warfare missions, deciding the outcome of any campaign either in the skies or the ground.
An Eagle Not to Mess With
The F-15 has proven to be a very powerful asset and a though adversary for those obliged to face it, feeling the powerful strike of the F-15. It has a suitable name that makes honour to its combat capabilities, which have been proven in action from the year it was unleashed. During the 1991 Gulf War and the aftermath, the F-15 achieved air superiority and delivered hard blows to the Iraqi military assets, by scoring 32 fixed-wing aircraft as confirmed kills (Iraqi fighters, fighter/bombers, transport airplanes and trainers that fell under the claws of the F-15), and 4 helicopters as kills. Many of these kills were achieved in air-to-air combats or simply by attacking the Iraqi air assets on the ground, being involved also in the hunt for valuable targets or by watching the skies over Iraq and the Balkans. In the hands of Israel and Saudi Arabia, the F-15 Eagle scored 41 and around 4-5 air kills respectively. With Israel, the F-15 left a deep impression on those that were targeted by its bombs. In the Balkans, the F-15 scored four air kills and equally contributed to pound the Serbian military facilities at Bosnia, Serbia and Kosovo.
The Eagle began the 21st century with more capabilities to increase its striking power, as well as seeing more combat in the light of the 9/11 attacks and the campaigns against terrorism. During the Second Iraq war of 2003, the Eagle once and again delivered precision strikes that decimated Iraq’s combat capacities. During the Afghan campaign, it attacked key Taliban and terrorist targets, at the point of even supporting the troops on the ground, and in recent years, it contributed at weakening the military power of Libya during its own Arab Spring, as well as striking important targets in the anti-terrorist campaign over Syria, Libya and Iraq. The F-15 Eagle has been on active duty basically during its entire operational life, being at the very first line.
The Eagle, as a last, could be able to destroy the eyes above the skies, as it was used for experimental tests where it fired a two-staged anti-satellite missile, proving capable for doing so. It has more than fulfilled the requirements set for its development after the nasty experiences of the Vietnam War, war that gave birth to one of the most powerful and memorable birds in all the history of aviation, being the Eagle a milestone by itself.
Variants
- F-15 Prototypes Series – These series comprised at least 12 different airframes (2 F-15A-1; 3 F-15A-2; 2 F-15A-3; 3 F-15A-4; 1 two-seat F-15B-1 and 1 two-seat F-15B-2), each having a specific purpose during development, like testing the engines, the avionics, the structure, armament and fire control systems, external payload, electronic warfare systems, and even test and demonstrations tasks.
- F-15A – The first series and operational version of the Eagle, being a single-seat all-weather air superiority fighter version. 384 units delivered.
- F-15B – Two-seated training version that received once the denomination TF-15A. 61 units delivered.
- F-15C – An improved version of the single-seat and all-weather superiority fighter version, receiving the last 43 units AN/APG-70 and AN/APG 63(V)1 radar. 483 units delivered.
- F-15D – Another two-seat version for training purposes. 92 units delivered.
- F-15E Strike Eagle – The all-weather strike version, as its name indicates, and equipped with conformal external tanks. Optimized for ground attacks, it was one of the main air assets used by the Coalition in Iraq in 1991, by NATO during the Balkans campaigns, the USAF in the second Iraq War, and on neutralizing combat capacities of terrorist groups. introduced in 1987.
- F-15J – Japan Air Self Defence Force version of the single-seat and all-weather air superiority fighter. 2 units made in the USA, and 139 built under license in Japan by Mitsubishi Heavy Industries.
- F-15DJ – Japan Air Self Defence two-seat version for training purposes. 12 units built in the USA, and 25 built under license in Japan by Mitsubishi Heavy Industries.
- F-15SE Silent Eagle – A proposed version with stealth capabilities by reducing the radar cross-section, having also new and specific avionics to be incorporated. This version has given way to the following versions:
- F-15I Ra’am – Version for Israel and thus operated by the Israeli Air Force with the name of Ra’am or ‘Thunder’. It has two seats and is for ground-attack missions, fitted with Israel-made electronics, including Sharpshooter targeting pods for night-time attacks, Elisra SPS-2110 radar warning receivers, a new central computer and GPS/INS system. Furthermore, the Display and Sight Helmet (DASH) allows the incorporation of all sensors, enhancing targeting. The APG-70I radar allows access to hard targets on the ground, capable also of detecting airliner-size target at distances up to 280 km (182 miles) and a fighter-size target at 104 km (64 miles). It will receive structural reinforcements, AESA radar and new weaponry. Around 25 units.
- F-15K Slam Eagle – Version for the Republic of Korea (South Korea), with 40% of the airframes comprised of South Korean-made components, including wings, fuselage, avionics, electronics and licence-built engines, with Boeing in charge of final assembly. A first batch was received in 2005 with 40 fighters received, followed by a second batch of 21 units ordered in 2008, having the Pratt & Whitney F100-PW-229 engines. This version has its own particularities, just like the F-15I, with an AAS-42 infra-red search and track device, a customized Tactical Electronics Warfare Suite aiming at reducing weight and enhancing jamming effectiveness, cockpit compatibility with NVG, and VHF/UHF radio with a Fighter Data Link system. Moreover, it is fitted with an advanced APG-63(V)1 mechanical-scanned array radar, upgradable to AESA radar, and having a Joint Helmet Mounted Cueing System. The armament is pretty ‘unique’ as well, as it carries AGM-84K SLAM-ER, AGM-84H Harpoon Block II anti-ship missiles, and AGM-158 Joint Air-to-Surface Standoff Missile JASSM (a low observable standoff and long range cruise missile).
- F-15S and SA – Variant supplied and developed for Saudi Arabia, with the F-15S having the AN/APG-70 radar and General Electric F110-GE-129C. The F-15SA will incorporate fly-by-wire flight control technologies (that will allow the carriage of weaponry on the unused wing stations, APG-63(V)3 AESA radar, digital electronic warfare systems, infra-red search and track systems and a redesigned cockpit.
- F-15SG (or F-15T) – Version operated by the Republic of Singaporean Air Force (RSAF) with 24 units. These units operate with AIM-120C and AIM-9X missiles, GBU-38 JDAM bombs and AGM-154 JSOW missiles, complemented with NVG and Link 16 terminals, powered by General Electric F110 engines.
- F-15QA – 72 units that will be delivered for the Qatar Air Force.
- F-15H Strike Eagle – A proposed version for Greece (H stand for Hellas, the Greek name of the country) that did not advanced further, as the Greek government chose instead Mirage 2000-5 and F-16.
- F-15G Wild Weasel – A proposed two-seat version to replace the F-4G in Suppression of Enemy Air Defences tasks, but the F-16 received such capabilities, and the F-15E was capable of carrying anti-radar missiles, like the AGM-88 HARM, thus performing SEAD roles.
- F-15N Sea Eagle and F-15N-PHX – A carrier capable version proposed in the early 70’s as an alternative to the Grumman F-14 Tomcat. The F-15N-PHX was also a proposed naval version for the US Navy, capable of carrying the AIM-54 Phoenix missile. As naval versions, these featured structural reinforcement at the wingtips, the landing gear and a tailhook for carrier operations. These versions would never see action as the US Navy decided to carry on with the Tomcat.
- F-15 2040C – A proposed upgrading programme for the F-15C to enable co-operation with the F-22, with characteristics similar to those of the F-15SE and having more air capabilities and combat power. Infra-red search and track, instalment of quad racks (increasing the missile carriage up to 16), Passive/Active Warning Survivability System, conformal fuel tanks, upgraded radar (APG-63(V)3 AESA, and a Thalon HATE communications pod for co-operation with the F-22 are among the proposed upgrades.
- F-15 Streak Eagle – A research unit without painting and avionics, which broke time-to-climb records. Now part of the National Museum of the United States Air Force.
- F-15 STOL/MTD – Another experimental unit for short-take-off/manoeuvre technology demonstrator, incorporating canards before the main wings, thrust-vectoring nozzles, and vectorised engine thrusts.
- F-15 ACTIVE – A modification of the F-15 S/MTD with thrust vectoring nozzles for advanced flight control research. The acronym ‘ACTIVE’ stands for Advanced Control Technology for Integrated Vehicles. NASA, Pratt & Whitney, United Technologies, the USAF, West Palm Beach and McDonnell Douglas Aerospace are in charge of the program. This unit is powered by Pratt and Whitney F-100-PW-229 engines fitted with modified axisymmetric vectoring nozzles
- F-15 IFCS – Conversion of the F-15 Active into a research aircraft for intelligent flight control systems.
- F-15 MANX – Intended tailless variant of the F-15 Active that was never materialized.
- F-15 Flight Research Facility – Two F-15 A acquired by NASA (Dryden Flight Research Center) for Highly Integrated Digital Electronic Control, Adaptive Engine Control System, Self-Repairing and Self-Diagnostic Flight Control System, and Propulsion Controlled Aircraft System experiments.
- F-15B Research Testbed – Used by NASA (Dryden Flight Research Center) for flight tests.
Operator
- United States of America
The F-15 is operated mainly by three services or institutions in the United States. One is the USAF, which operates around 255 F-15 of the C/D versions, with the Air National Guard being the second service and operating 140 of them. In addition, the USAF operates 213 F-15E. Many of USAF F-15 saw extensive action in Operations Desert Shield and Desert Storm in Iraq in 1990 and 1991. On these operations, F-15 of C and D versions gained air superiority, killing 5 Iraqi Mig-29, 2 Mig-25, 8 Mig-23, two Mig-21, 2 Su-25, 4 Su-22, one Su-7, six Mirage F1, one Ilyushin Il-76 cargo airplane, one Pilatus PC-9 trainer, and 2 Mil-8 helicopters. In the 1999 Kosovo campaign, four Serbian Mig-29 were scored as kills by the F-15C.Meanwhile, the F-15E’s hunted SCUD launchers, engaged against Iraqi Mig-29 fighters and even shot down a Mil-24 Hind with a bomb, losing only two units. Iraqi air assets were also destroyed by the F-15E, as well as enemy armoured assets in Kuwait, engaging also in operations intended at killing Saddam Hussein. Operations Southern Watch and Northern Watch, which followed in the aftermath of the Gulf War, saw the F-15E enforcing the no-fly zone, managing to cause one Iraqi helicopter – a Hind – that was attacking a Kurdish site to crash. They also destroyed SAM sites and radars, as well as command and control sites, radio communications and relay stations, and radars. They also executed surveillance and reconnaissance, mission practicing and even strikes against the Iraqi Republican Guard and Baath Party HQs (Operation Southern Watch).In the Balkans, the F-15E were used to strike Serbian targets in both Bosnia and Herzegovina and Kosovo mainly against armour, logistical, and air defences weapons and facilities targets of Serbia, where it executed for the first time, stand-off attacks with the AGM-130 missile. Operations Enduring Freedom and Iraqi Freedom saw the deployment of USAF F-15E for the second time in Iraq and in Afghanistan, following the 9/11 attacks. In Afghanistan, the F-15E engaged in strikes against Taliban and terrorist targets – military structures, supply depots, training camps, and caves – as well as in CAS missions, where they gave support fire to a SEAL team whose helicopter was shot down. In Iraq, in turn, the F-15E attacked key military and governmental sites, airfields – 65 Migs destroyed – and decimating 60% of the Iraqi Medina Republican Guard.Libya, Syria and Iraq are the areas the USAF F-15E are currently in action, attacking ISIS terrorist training camps, facilities, command and control facilities and even vehicles and trucks. But the USAF utilization of the F-15 did not stopped there, as in fact made the Eagle capable of firing anti-satellite missiles from 1984 to 1988, although on an experimental basis.The older F-15C and F-15D models are to be upgraded and to be operated beyond 2025, while the A and B versions were retired after being operated by the Air National Guard. They are intended to be gradually replaced by F-22 and F-35.NASA is the third US operator with a single unit for experimental purposes.
- Israel
Israel is another operator of the F-15, which have seen extensive action with the Israel Air Force since 1977. Among its inventory, Israel has F-15A, F-15B, F-15C, F-15D and F-15I, where the F-15 scored its first ait-to-air kill over the skies of Syria by Israeli ace Moshe Melnik. They also saw extensive action over Lebanon, taking down 13 Mig-21 and 2 Mig-25 of the Syrian Air Force. They also escorted the F-16I during Operation Opera, an Israeli strike against an Iraqi nuclear plant, and during the Lebanese Civil War, the Israeli F-15 scored 23 Mig-21, 17 Mig-23 and one Gazelle SA.342L helicopter as air kills. They also attacked a terrorist headquarters in Tunis in 1985, as Israel was the first one in exploiting the air and ground capabilities of the F-15 as well as its range. The F-15I, in turn, can operate Israeli-made infra-red homing missiles in coordination with a helmet mounted sight, as well as air-to-air missiles. - Japan
Japan is another prominent operator of the F-15, as it has license-built version that fulfil its own requirements. The Japan Air Self-Defence Force therefore operates 12 F-15DJ for training purposes, and nearly 155 F-15J for their standard role of air superiority and ground-attack. - South Korea
The Asian nation has enrolled 58 F-15K Slam Eagle, defeating very capable fighters such as Dassault Rafale, the Eurofighter Typhoon and the Sukhoi S-35 during the selection program process for a new fighter. The Korean F-15 incorporate many electronics and avionics components made in South Korea, as well as enhanced radars and other equipment, being mostly assembled in South Korea. - Singapore
40 F-15G are operated by the Republic of Singapore Air Force. - Saudi Arabia
The Middle East Kingdom received 75 F-15C and F-15D, seeing action for the first time in 1984, shooting down two Iranian F-4E Phantom II during an aerial skirmish. The Saudi F-15 would also see action in the 1991 Gulf War, killing two Mirage F-1 of the Iraqi Air Force, losing one during the conflict. Later on, Saudi F-15S have co-operated with Saudi Panavia Tornados in strikes against Houthi insurgents in Yemen, as part of Saudi-led efforts against this group, concentrating on air defence sites, army HQ, airfields, ballistic missile depots and launchers. A single F-15S was lost during the operation’s early stages. This nation has also received F-15SA.
F-15C Specifications |
|
Wingspan | 13,05 m / 42 ft 10 in |
Length | 19,43 m / 63 ft 9 in |
Height | 18,6 m / 13 ft 5,63 in |
Wing Area | 56,5 m² / 608 ft² |
Engine | 2 X Pratt & Whitney F-100-PW-100 or PW-200 or PW-229 afterburning turbofans |
Maximum Take-Off Weight | 30845 Kg / 68,000 lb |
Empty Weight | 12700 kg / 28,000 lb |
Loaded Weight | 20200 kg / 44,500 lb |
Climb Rate | more than 50,000 ft/min (254 m/s) |
Maximum Speed | At high altitude: Mach 2,5+ (2665+ km/h / 1,650+ mph), At low altitude: Mach.1,2 (1450 km/h / 900 mph) |
Range | 1967 Km / 1,222 miles for combat radius; 5550 Km / 3,450 miles on ferry |
Maximum Service Ceiling | 20000 m /65,000 ft |
Crew | 1 (pilot) |
Armament |
|
Gallery
Sources
Berger, R (Ed.). Aviones [Flugzeuge, Vicenç Prat, trans.]. Colonia, Alemania: Naumann & Göbel Verlagsgessellschaft mbH., Boeing. (2016). F-15 Strike Eagle. Boeing. Retrieved from: http://www.boeing.com/defense/f-15-strike-eagle/ on 06.12.2016, Chambers, J. R. (2000). Partners in Freedom. Contributions of the Langley Research Center to US Military Aircraft of the 1990’s (NASA monograph NASA SP-2000-4519). NASA History Division: Washington DC, USA. Retrieved from: https://www.nasa.gov/centers/langley/pdf/70897main_PiF.pdf on 25.11.2016, Sharpe, M (2001). Jets de Ataque y Defensa [Attack and Interceptor Jets, Macarena Rojo, trans.]. Madrid, Spain: Editorial LIBSA (Original work published in 2001)., Donald. D. (2009). Aviones Militares, Guia Visual [Military Aircraft. Visual Guide, Seconsat, trans.]. Madrid, Spain: Editorial Libsa (Original work published in 2008)., Dudney, R. S, &. Boyne, W. J (December 2015). Airpower Classics. F-15 Eagle/Strike Eagle. Air Force Magazine, 98 (12), 76. Retrieved from: http://www.airforcemag.com/MagazineArchive/Magazine%20Documents/2015/December%202015/1215classics.pdf on 25.11.2016, GlobalSecurity.org. (2011). F-15 Eagle Fighter. GlobalSecurity.org. Retrieved from: http://www.globalsecurity.org/military/systems/aircraft/f-15.htm on 07.12.2016, Lemoin, J (2002). Fighter Planes. 1960-2002. Retrieved from: http://sim-deck.co.uk/wp-content/uploads/downloads/fighter-planes%201960-2002.pdf on 07.12.2016, Neufeld, J. (1974). The F-15 Eagle. Origins and Development, 1964-1972. Office of Air Force History: USA. Retrieved from: http://www.afhso.af.mil/shared/media/document/AFD-120516-036.pdf on 25.11.2016, Smolka, J. W., Walker, L. A., Maj. Johnson, G. H., Schkolnik, G.S., Berger, C. W., Conners, T, R., Orme, J. S., Shy, K. S., Wood, C. B. (n.d.). F-15 ACTIVE Flight Research Program. Retrieved from: https://www.nasa.gov/sites/default/files/89247main_setp_d6.pdf on 25.11.2016, US Government Accountability Office. (2012). Tactical Aircraft: Comparison of F-22A and Legacy Fighter Modernization Programs (Report GAO-12-524). US Government Accountability Office: Washington DC, USA. Retrieved from: http://www.gao.gov/assets/600/590505.pdf on 25.11.2016, Wikipedia on the MacDonnell Douglas F-15: https://en.wikipedia.org/wiki/McDonnell_Douglas_F-15_Eagle, Wikipedia on the McDonnel Douglas F-15E Strike Eagle: https://en.wikipedia.org/wiki/McDonnell_Douglas_F-15E_Strike_Eagle, Wikipedia on the McDonnell Douglas F-15Stol/MTD: https://en.wikipedia.org/wiki/McDonnell_Douglas_F-15_STOL/MTD, Wikipedia on the Boeing F-15SE Silent Eagle: https://en.wikipedia.org/wiki/Boeing_F-15SE_Silent_Eagle Images: F-15E Grand Canyon by darinm16 / CC BY-ND 2.0, F-15l Raam – Israel by mykaul / CC BY-ND 2.0, F-15 Engines by Rennett Stowe / CC BY 2.0, F-15A Display by Clemens Vasters / CC BY 2.0, F-15E Banking by Jez / CC BY-NC-ND 2.0, Side Profile Views by Ed Jackson – Artbyedo.com
It’s the Republic of Singapore Air Force, not Royal. The island nation is a republic.
Thank you for the correction!