The McDonnell Douglas F-15 Eagle is an American Mach 2.5-class twin-engine fighter, all-weather tactical fighter aircraft designed by McDonnell Douglas (now Boeing) to gain and maintain air supremacy in aerial combat. It is among the most successful modern fighters, with over 100 victories and no losses in aerial combat, with the majority of the kills scored by the Israeli Air Force.
Forseeing the need to replace its fleet of F-4 Phantoms, the US Air Force issued the FX requirement for a long-range air superiority fighter in 1965.
Performance requirements called for beyond visual range air-to-air capability, close-in dogfighting capability, twin engines, an internal gun, sufficient ferry range to deploy to Europe without refueling, and a maximum speed of Mach 2.5. McDonnell Douglas was selected over rivals North American and Fairchild Republic to build what would become the F-15 Eagle.The Eagle first flew in July 1972, and entered service in 1976.
The Eagle has been exported to Israel, Japan, and Saudi Arabia, among other nations. The F-15 was originally envisioned as a pure air superiority aircraft. Its design included a secondary ground-attack capability that was largely unused. The design proved flexible enough that an all-weather strike derivative, the F-15E Strike Eagle, was later developed, entering service in 1989. The F-15 Eagle is expected to be in service with the U.S. Air Force past 2025. Newer models are still being produced for foreign users. The F-15 production line is set to end in 2019, 47 years after the type's first flight.
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| McDonnell Douglas F-15A (S/N 71-0280) during the type's first flight |
During the Vietnamese War, USAF fighter pilots and Air Force leaders were angered at the deficiencies of their equipment and training that resulted in a two-to-one or even one-to-one kill ratio, compared to the ten-to-one kill ratio of the Korean War.
They wanted a new fighter that would gain not air superiority but air dominance, and win its battles with few or no losses. It had to be fast and maneuverable, and have great visibility and long range. Armed with missiles and a gun, it was to have both beyond-visual-range (BVR) and close-in dogfight capability. It would make maximum use of the concept of "energy maneuverability" as advocated by then Major John Boyd.
In January 1965, Secretary McNamara asked the Air Force to consider a new low-cost tactical fighter design for short-range roles and close air support to replace several types like the F-100 Super Sabre and various light bombers then in service. Two basic designs could fill this role; the Navy favored designs like the Douglas A-4 Skyhawk and LTV A-7 Corsair II, pure attack aircraft, while the Air Force was more interested in fighter-bombers like the Northrop F-5, fighters with a secondary attack capability. The former were more capable in the tactical role, while the latter might be less so but could defend themselves. If the Air Force did choose an attack design, maintaining air superiority would be a top priority. The next month, a report on light tactical aircraft suggested the Air Force purchase the F-5 or A-7, and consider a new higher-performance aircraft to ensure its air superiority. This point was driven home after the loss of two Republic F-105 Thunderchief aircraft to obsolete MiG-15s or MiG-17s on 4 April 1965.
The effort did lead to a second request for proposals (RFP) in February 1968. In that time the Air Force had learned some lessons from air combat over Vietnam that showed existing fighters like the F-4 left something to be desired, and also had become aware of new Soviet threat aircraft, such as the Mikoyan MiG-25 "Foxbat", that the F-4 could not hope to deal with. The Air Force saw the FX from the outset as a long-range air-superiority fighter, engaging adversary aircraft from "beyond visual range (BVR)" with AIM-7 Sparrow air-to-air missiles (AAMs). The fighter would also be capable of close-in combat, and would have a (strictly secondary) strike capability.
The 1968 RFP elaborated on this by specifying a twin-engine, single-seat fighter with a built-in cannon, the omission of which was found to be a major fault with the F-4; a ferry range long enough to permit self-deployment to Europe without tanker support; and a top speed of Mach 2.5. There had been a push to specify a two-seat aircraft in the RFP, but the single-seat configuration won out -- though the two-seat configuration would also be built for operational conversion. The Mach 2.5 spec now seems extreme, a reflection of the infatuation with raw speed that lingered through the 1960s, coupled with fear of being outclassed by the Foxbat and other new Soviet fighters. The RFP also called for self-contained engine starting, good pilot field of view, easy maintenance, and a takeoff weight of no more than 18,150 kilograms (40,000 pounds).
Most American aircraft manufacturers submitted proposals, with the field whittled down to McDonnell Douglas, North American, and Fairchild Republic by the end of 1968. The competition was won by MDD a year later, on 23 December 1969. The initial contract specified delivery of:
#Ten single-seat "F-15A" development machines, sometimes informally referred to as "YF-15As".
#Two tandem-seat "TF-15As".
#Eight "full-scale development (FSD)" F-15A single-seaters.
The first ten F-15As were referred to as "Category I" machines, while the following eight F-15As were referred to as "Category II" machines.
The MDD F-15 design team was led by George Graff, though early design work owed much to Herman Barkey, who had led the design effort for the F-4. Program management was under Don Malvern, also a veteran of the F-4 effort.
The design work was assisted by the construction of three 3/8ths-scale unpowered drone versions of the fighter. These robots were referred to as "remotely piloted research vehicles (RPRVs)" and were taken aloft over Edwards Air Force Base (AFB) in California by the US National Aeronautics & Space Administration's (NASA) NB-52A carrier aircraft, to be released at high altitude. They would glide back to earth and land on retractable skids on the dry lakebed at Edwards. The RPRVs could also be fitted with a parachute to be "snagged" by a helicopter in flight for recovery. Each drone weighed 1,099 kilograms (2,425 pounds) and had a length of 7.01 meters (23 feet). They were made of aluminum, wood, and fiberglass and cost only $250,000 USD each. They provided extremely valuable flight data, and the exercise was regarded as extremely useful and cost-effective.
The first Category I F-15A was rolled out at Saint Louis on 26 June 1972. It was broken down, loaded onto a Lockheed C-5A cargolifter, flown to Edwards AFB, and then reassembled to perform its first flight on 27 July 1972. MDD chief test pilot Irving Burrows was at the controls, and the flight was uneventful. The initial flight of the first two-seater was on 7 July 1973.
All twenty of the test and evaluation machines flew in neat light-blue overall colors, and in the early days of flight testing of the Category I machines had high-visibility dayglow orange paint applied to the wingtips and other selective elements to make them easier to observe. Many of these aircraft would go on to have extensive careers in the test and trials role. In 1976, the second TF-15A was painted in patriotic red-&-and-blue colors for the American bicentennial and sent on a world promotional tour, which included an impressive display at the Farnborough Air Show in the UK.
Manufacture of an initial batch of 30 full-production F-15s was announced on 1 March 1973, leading to initial service delivery in September 1974 and introduction to operational service in January 1976. By that time, the type had acquired its formal name of "Eagle". While formal names have a habit of being ignored by aircrews in favor of less formal and occasionally irreverent nicknames, in this case the "Eagle" name appears to have stuck fairly well.
Design
The F-15 superior maneuverability and acceleration are the result of a high engine thrust-to-weight ratio and low wing loading.
The low wing-loading, the ratio of aircraft weight to its wing area, combines with high thrust-to-weight ratio to enable the aircraft to turn tightly without loosing speed.
The F-15 can climb to 30,000 ft (10,000 m) in around 60 seconds and can reach speeds over Mach 2.5 at high altitudes.
The F-15’s are powered by Pratt & Whitney F100 engines and the the first F-15A’s and B’s came equipped with a standard M61 Vulcan gun and four Sparrow missiles.The F-15 comes complete with an advanced multi system avionics system that sets it apart from other fighter planes. tactical electronic-warfare system
The F-15’s electronic warfare system provides both threat warning and automatic countermeasures against selected threats.
The tactical electronic-warfare system, upgraded in all existing models of the F-15, includes: advanced radar, radar jammer, “identification friend or foe” system, head-up display, inertial and tactical navigation system, instrument landing system, electronic countermeasures set and a central digital computer.
The F-15 has a “look-down/shoot-down” radar that can distinguish low-flying moving targets from ground clutter. Using this pulse-doppler radar system the aircraft can identify small high-speed targets beyond visual range.
The radar feeds target information into the central computer for effective weapons delivery. For close-in dog fights, the radar automatically acquires enemy aircraft, and this information is projected on the head-up display.
The head-up displays projects all essential flight information on the windscreen. The display, which can be viewed in any light, eliminates the need to look down at the controls.
To supplement the radar jamming system, a Fiber Optic Towed Decoy (FOTD) offers protection against radar-guided missiles. The device is towed behind the aircraft whilst emitting a stronger radar signal than the plane itself.
The “identification friend or foe” system informs the pilot if an aircraft seen visually or on radar is friendly. It also informs U.S. or allied ground stations and other suitably equipped aircraft that the F-15 is a friendly aircraft.
Performance
F-15G - Max level speed over Mach 2.5, or approx 2655km/h (1433kt). Max initial rate of climb over 50,000ft/min. Service ceiling 60,000ft. Ferry range with external fuel and conformal fuel tanks over 5745km (3100nm). Combat radius on an intercept mission 1965km (1060nm). Endurance with conformai fuel tanks 5hr 15min.
Operational History
The USAF introduced the F-15 as “the first dedicated USAF air superiority fighter since the F-86 Sabre.”
The first F-15A flight was made in July 1972 with the its two-seater brother designed for training purposes, the F-15B, following in July 1973.
Around 365 F-15A’s and 61 F-15B’s were produced between 1972 and 1979, at which point, the revised F-15C and the two-seat F-15D entered service.
Additions incorporated in the F-15C included upgrades to avionics as well as increased internal fuel capacity and a higher allowable gross takeoff weight. Low-drag, conformal fuel tanks were added to the aircraft without sacrificing external stations for munitions, in fact the fuel tanks allowed for AIM-7F/M Sparrow and AIM-120 missiles to be attached to the corners.
The first flights of the F-15C and F-15D took place in June 1979.
The F-15C and F-15D entered the Air Force inventory in 1979 with Kadena Air Base, Japan, receiving the first F-15Cs in September.
The F-15C has an overall air combat victory ratio of 95-0, making is one of the most successful air superiority aircraft ever developed.
The F-15E Strike Eagle entered the Air Force arsenal in 1988, modifications included an extra cockpit station and air to ground bombing capabilities.
F-15C’s, F-15D’s and the F-15E were deployed to the Persian Gulf in 1991 in support of Operation Desert Storm, earning a confirmed 26:0 kill ratio.
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| M61 Vulcan mounted on the side of right engine intake |
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| F100-PW-100 on display at the Virginia Air and Space Center |
The F-15 has had a very active and successful past, it is estimated that the aircraft will stay in service until at least 2025.
McDonnell Douglas F-15 Eagle Specifications
Wingspan: 42 ft. 9-3/4 in.
Length: 63 ft. 9 in.
Height: 18 ft. 5-1/2 in.
Empty Weight: 28,600 lbs
Gross Weight: 68,000 lbs
Top Speed: Mach 2.5
Service Ceiling: 60,000 ft-plus
Range: 3,000 miles
Engine/Thrust: Two Pratt & Whitney F100 turbofans/23,900 lbs of thrust each
Crew: 1
Armament: One MA61A1 20-mm six-barreled cannon; four AIM-9 Sidewinder missiles; four AIM-7 Sparrow missiles; or eight AIM-120 AMRAAM air-to-air missiles
Ordnance: Up to 16,000 lbs of external load