Recently I received a most intriguing request: I was asked to build a self-contained, super-bright X-Y display unit with 3-inch CRT, for use in an “HUD“. Hmm…
Holographic Utterance Device?
Horizontally Unstable Doohickie?
…
Fortunately, I didn’t need to guess any further. As I was once an avid flight simulator enthusiast, I quickly hit upon the correct meaning: Head-Up Display. This is a mechanism that overlays instrumentation or map data onto the view looking forward from the cockpit, so that the pilot doesn’t have to look down to see this information.
![HUD in an F-18 aircraft. Source: AC Aviation Life](https://i0.wp.com/oscilloclock.com/wp-content/uploads/2015/04/F-18-Aircraft-HUD-.jpg?resize=584%2C438&ssl=1)
HUD in an F-18 aircraft. Source: AC Aviation Life