Why Did the U.S. Air Force Dump the F-111 Aardvark for the F-15?
Both warplanes had their merits.
Here's What You Need to Know: The F-111 could do things the F-15 could not.
The F-111 Aardvark was the U.S. Air Force’s premier strike aircraft for the majority of the Cold War. It served in practically every conflict from Vietnam forwards, until it was replaced by the F-15E Strike Eagle. It also served Strategic Air Command in a limited role as a strategic bomber.
But what made the F-111 great? Did the United States truly lose any capability by retiring it?
The F-111 was one of the earliest joint-service aircraft, meant to fulfill both the U.S. Air Force’s requirement for a swing wing strike bomber and the U.S. Navy’s requirement for a long-range interceptor.
The strike bomber role meant that it needed to go very low and fast to penetrate enemy air defenses. As a result, it was fitted with an advanced terrain following radar, swing wings for increased maneuverability at low speeds, and a generous bomb bay. Later NATO strike aircraft like the Panavia Tornado would gain a lot of design cues from the F-111, including the radar and swing wings.
The F-111 first was tested in combat in Vietnam during 1968, but issues with the design delayed its full fielding until Operation Linebacker. It would go on to become one of the most survivable bombers of the war due to its ability to penetrate at a low level, with only a 0.015 loss rate.
However, the F-111 would be rejected from the Navy’s competition to find a long-range interceptor in favor of a design that would become the more maneuverable F-14 Tomcat.
The Air Force was pleased with its performance and continued to upgrade the F-111. The F-111D was one of the first combat aircraft with a “glass cockpit,” that featured primarily screens instead of gauges to display information. It also featured some of the most advanced avionics of the time.
The F-111 also received the AN/AVQ-26 Pave Tack targeting pod, a device that combined a laser designator with an IR camera. It allowed the aircraft to self-designate targets for attack with laser-guided munitions. The Pave Tack was used to great effect during Operation Desert Storm to destroy individual tanks with accurate hits from laser-guided bombs.
But the F-111’s replacement, the F-15E Strike Eagle could do all of these things too. It could use targeting pods, it had a modern glass cockpit, and it could do low-level insertion. The Strike Eagle could also fight enemy aircraft on its own, as it inherited the powerful air-to-air radar and integration with the latest air-to-air missiles from its parent aircraft, the regular F-15.
The F-111 did have an advantage though. Both the initial requirements for the Navy and the Air Force required that the F-111 have a massive range. Comparing ferry ranges, the F-111 has over 60 percent more range than the F-15E Strike Eagle, with the Strike Eagle using external fuel tanks.
The F-111’s additional range allowed it to be strategically flexible. F-111s based in the United Kingdom were used to strike Libya during Operation El Dorado in 1986. The range was also greatly appreciated by Strategic Air Command, which fielded a the FB-111 variant as a strategic bomber. In that role, the F-111 was only replaced by the B-1 Lancer.
While shorter ranged aircraft are far cheaper to maintain and use, the F-111 struck a weird medium between the tactical strike aircraft and the strategic bomber. That medium allowed it to serve admirably during the Cold War, and the design should not be discounted as a weird compromise.
Charlie Gao studied political and computer science at Grinnell College and is a frequent commentator on defense and national security issues.
This article first appeared in March 2019.
Image: U.S. Air Force / Wikimedia Commons