A few days ago, California-based defense tech firm Anduril concluded the first test flights of its semi-autonomous Fury fighter jet without a pilot in the cockpit. Oh wait, there's actually no cockpit in there at all.

The small and nimble FRS.1 Sea Harrier defied the prevailing logic of the 1970s and 1980s, in which air forces competed to build bigger and faster fighter jets.

According to the GAO, maintenance crews often face delays that stretch to months waiting for components, forcing them to strip other assets.

The United States Air Force (USAF) has been the home of some of the world’s most iconic fighter jets. However, as technology advances and new models are introduced, some of these legendary aircraft are being retired.