Title: Do fighter-jet pilots carry guns in case they have to eject or land in enemy territory? If so, what type of guns do they have? Does the weapon carried change according to the mission? - Quora
Headings: 
Marines carry a Kabar knife and a 9mm semi-automatic.
Content: The pilot and weapons officer (if it’s a two person crew) are far more valuable as a substantial force multiplier in the cockpit of a fighter than being a ground pounding grunt with a handgun. The training received for such events is called SERE Training: S urvival, E vasion, R esistance and E scape. Emphasis is on survival and evading confrontation or capture while working one’s way toward friendly territory. It’s about maintaining acute situational awareness of the Bad Guys trying to close in on you while using methodical stealth to work your way toward friendly territory. Shooting a pistol attracts considerable attention and tells everyone within earshot, especially those trying to capture (or kill) you, where you are when you fire it. A pistol report travels a considerable distance. Unless there’s an active firefight or some other very high ambient noise in the vicinity to mask it, it’s at least a quarter mile, usually farther. I can very easily hear the reports from firearms on an outdoor range a half-mile from my house (it’s not used that often). The pistol is a weapon of absolute last resort.