Here’s a change of pace from our regular procurement game. Let’s go back to a time before precision guidance was all the rage. A time when Saigon was still Saigon (albeit about to fall). A time when a favorite marching cadence was ‘Napalm Sticks to Kids’. A time when the Soviet Union was extant and terrifying and, yes, a time when Gerald Ford was in the white house. Welcome to the mid-1970s. Borgundy is still a reasonably well off European nation, a proud NATO member squaring off against the Warsaw Pact. We’d like a big new frontline fighter for the defense of our realm, and the best and latest in advanced western types are both American: the Grumman F-14A and the McDonnell Douglas F-15A. Let’s compare them, and see which comes away with the win. Remember, it’s 1975, so we can’t let any knowledge of how these two planes shook out affect our choice.
We’ll start with the Grumman offering, since it’s newer. The Grumman F-14 can be thought of as the ultimate fleet defense fighter. It’s built more or less to the same concept that gave birth to the fabulously successful F-4 Phantom II, but supersized, and uses the latest aerodynamics technology. It’s designed to have a long operating range and endurance, so it can fly a good distance out from the carrier, from where it will engage Soviet bombers before they can launch their missiles. To that end, it has plenty of fuel storage, high-tech swing wings for good speed and short-field performance, the most powerful fighter radar in the world (the AWG-9), and the longest range air to air missile in the world (the AIM-54 Phoenix). The Phoenix even has a fancy active seeker, unlike those lame semi-active seekers on the USAF standard Sparrow missile. Like the Phantom, the Tomcat has a two-man crew, one pilot, and one to operate the advanced radar system. It has the same TF30 turbofans as the F-111, however. Peformancewise, the F-14 was designed to match the Phantom as far as speed and maneuverability goes, but have a main armament that’s much longer ranged. And unlike the F-4, it does have a gun–the US Navy learned its lessons from Vietnam.
The McDonnell Douglas F-15 is designed to be the ultimate air superiority fighter, something the US Air Force hasn’t had in years. It is designed to be able to beat any current or projected future fighter type in air to air combat. The US Air Force took the Vietnam lessons to heart too. The Eagle is faster than the F-4, and is second only to the MiG-25 in top speed. It’s more agile overall than the F-4 or the F-14 because of it’s superior thrust to weight ratio and structural tolerance for more Gs. Like the F-14, it has a 20mm M61 Vulcan cannon with plenty of ammunition for a shootout or a strafing run. It does not carry the Phoenix missile, instead it carries Sidewinders and Sparrows, just like the Phantom. Unlike the Phantom and the Tomcat, the Eagle is a single seat fighter. It’s radar, while more advanced than the APQ-72 on the Phantom, is less powerful than the AWG-9 of the F-14. However, automation allows a single pilot to use it effectively. The F-15 was designed with offensive counter-air sweeps in mind, just like USAF F-4s flew in Vietnam.
So how do these two compare? Contractwise at about this time, they’re dead even. The Shah of Iran chose the F-14, the Israelis chose the F-15. Which will we choose? Well, the F-14 has the better sensor suite by far, with the AWG-9 being able to track 24 targets simultaneously, and attack up to six with Phoenix missiles. It even has look-down/shoot-down capability. The Tomcat also has an infrared search and track system mounted under the nose to help with target identification. While the F-15 also has a look-down/shoot-down capable radar in the APG-63, it has less range, simultaneous tracking capability, and simultaneous engagement capability. What it does have are a number of semiautomatic modes that make it very easy for a single crewman to employ in combat. The F-14 was designed to operate (more or less) on it’s own on extended patrols protecting a carrier battle group, or covering a Vietnam-style strike package from Yankee Station. The F-15 was designed with the significant USAF support assets of AWACS and jamming aircraft in sweeps to support strike packages, again, as in Vietnam. It also has a superior IFF system. Recent experience in the air war over Vietnam has demonstrated that beyond visual range methods are not as guaranteed as the missile manufacturers claim. The long-range AIM-54 was designed to kill bombers, and we are somewhat skeptical of its ability to effectively kill agile enemy fighters at range.
Vietnam demonstrated that air combat maneuvering capability is important, and the F-15 excels here. Part of this is because it’s a lighter, smaller plane. It carries less fuel. It’s structure is also rated to handle more G-force than that of the F-14. The F-15 also has far superior engines. In order to cut costs, the US Navy tried to re-use as much as it could from the colossal failure that was the F-111B, and that included the engines. However, not only does this give the F-14A a rather anemic thrust-to-weight ratio, but the TF30 is also very prone to compressor stalls at high angles of attack. It was never designed for a platform that would maneuver aggressively. And because the Tomcat’s engine nacelles are widely spaced, in order to provide room ot carry the big AIM-54 missiles, a compressor stall in one engine can lead to a flat spin, which is very difficult to recover from.1
The Eagle is the cheaper fighter to procure, but the numbers I found may be colored by its larger production run. It isn’t that much cheaper though; they’re certainly in the same price class (like a Porsche and a Lamborghini). The F-15 is significantly cheaper to operate and maintain. It has a number of design elements that simplify maintenance, and it doesn’t have the complicated variable geometry wings.2 This translates into increased availability for sorties, and (of course) more sorties for the money.
Famously, the F-15’s unofficial design motto was “Not a pound for air to ground”, though this is probably apocryphal. As seen by the minor changes needed for the F-15E, McDonnell Douglas certainly put in enough structural strength for ground attack missions. The Tomcat is also capable of carrying plenty of bombs, though neither the USN nor the USAF has bothered to integrate any air to ground weapons into the stores management system. So that’s a wash. As far as air to air armament goes, the biggest difference is the massive (but also very expensive) AIM-54 on the Tomcat. In terms of number of missiles, both planes field eight air to air missiles. In the ‘small advantages’ column, the F-15 carries more ammunition for its 20mm cannon, with 940 rounds to the F-14’s 675.
So, what is the final decision? We’re going for the Eagle. Better air combat capabilities against fighters and lower operating costs put the F-15 ahead of the F-14 for us. The offensive counter air mission is a much bigger need than a long range interceptor. And if the Soviets come at us hard, it will probably be by land, and we’ll want to neutralize their frontline aviation while bombing the living daylights out of their second echelon, reserves, and logistics. We’ll actually need another plane for the mud-moving; the Eagle is expensive enough without us trying to make it into a ground attack aircraft on our own.
1.) See Top Gun for a hands-on demonstration of a nasty flat spin. At least it’s not inverted. Or you could, but this is 1975, and it hasn’t been made yet.
2.) Stepping out of 1975 for a moment, we can see this reflected in that the USAF still operates F-15s, but the USN phased the F-14 out of service in 2006. But we have no way of knowing that in 1975 of course. 2006 is a long way off in the future; people probably commute in flying cars or something weird like that.