That happens when you go into "tactical mode" (for the lack of a more precise term), which occurs when you uncage the SHKVAL or select a weapons station.
Just hit the reset button on the targeting panel (the panel on the left just aft of the VHF-2 console) to get your full HUD back.
"Pacifism is a shifty doctrine under which a man accepts the benefits of the social group without being willing to pay - and claims a halo for his dishonesty."
- Robert A. Heinlein
The average naval aviator, despite the sometimes swaggering exterior, is very much capable of such feelings as love, affection, intimacy, and caring. These feelings just don't involve anyone else.