In the past, we used thin, delta-shaped wings (ogival wings) such as those on the Concorde.
These wings can be used up to mach 2.2. Due to high fuel consumption, these wings are no longer used commercially. However, why can't they be used on fighter aircraft?
Yes, it is. It was used on 2nd generation designs already mentioned by habu, and it is returning now in the 4.5th generation, now with canards:
And occasionally without too:
And most of the other designs, while having horizontal tail surfaces, are not really far from that layout either:
The F-22 and F-35 with their negative sweep trailing edge are more of an exception, their layout being governed more by requirement for lower radar cross-section than aerodynamics.
The delta wing was, in fact, very widely used in fighter designs of the mid-late 50s, 60s, and early 70s. The Mirage series (even the latest models) and their derivatives, the MiG-21, the F-106, and the A-4 are some of the more iconic designs to have used the wing.
However, as time went on, shifting philosophies on aircraft design, along with technological and manufacturing advancement meant that the speed and acceleration attainable with Delta wings could be reached by other means and manufacturers were free to work with other types of wings that don't suffer from the Delta's weaknesses.
Taking what has already been said and talking it in a different direction… All military equipment design goes through an evolution based on who you think your enemy is, how you think they might attack you, and the systems and tactics with which you intend to counter that attack.
There was a time when having the fastest possible interceptors produced the best possible likelihood of intercepting an incoming bomber before it posed a nuclear threat to a populated or strategic area. But many thinkgs have changed.
The era of the overhead strategic bomber dropping a nuclear gravity bomb over its target is gone. Changing the role of the bomber profoundly changes the role of the interceptor, which profoundly changes the need for maximum speed.
The role of the cruise missile has changed the way bombers deploy weapons. even my fastest interceptors will likely arrive just in time to find an empty bomber.
The attack role—whether that is a tactical attack or a deep strategic strike, has become much more important in military planning, and that often means low radar observability is far for important than speed.
Radar and satellite capabilities to detect (and more importantly confirm) enemy bomber launch sequences has improved to the point where I have more time to get to interception points. I may know your bomber has taken off hours before it first encounters my surveillance radar.
The role of the anti-aircraft missile, and the performance of those missiles has evolved, in terms of speed, autonomy, threat resistance… My interceptor can launch from farther away, subs or missile cruisers can be placed strategically in times of escalating tension, etc. Land-based SAMs have evolved profoundly.
The likelihood of a strategic conflict and its unique need for interception has largely given way to the much higher likelihood of a very different kind of war. The US and Europe have shifted priorities away from prioritizing border aerial interception and toward global force projection, in the form of robust attack capability.
This list could keep going, and if we brainstormed, we’d come up with at least 5 or 6 more reasons why the mission of bomber interception has changed in a way that has relieved some need for speed. Put all these reasons in a blender and they all contribute to a change in aircraft design.
