Yes Army and Marines are certified to use pistols but it doesn't means they are issued with one. The majority don't.
The Mk 18 Mod. 0 and its variants more or less made sub-machine guns a thing of the past in the US military. I know for a fact that NAVY SEAL are not train to use sub-machineguns like the MP5 for sometime now. However, I'm sure there are elements in the US military that are train to use submachine-guns.
I do get a laugh when people thinks that pistol are offensive weapons. I mean movies do a good job at convincing people that pistol beat rifle 10 out of 10 times. If this were the case why carry a rifle when clearly in the movies a guy using a pistol killed 50 rifleman. Or the first chance the hero gets he ditch his rifle and go medieval with his pistol. Bring a pistol where everyone has rifles is like bring a knife to a gun fight in real life that is.
If you mean black hawk pilots. No they are not issue sub-machine guns like MP5 unless it's Special Operation but I doubt that too (probably Mk 18 variant by now). Normal Black Hawk pilots are issue with M9 pistol. Keep in mind the Somalia Operation (Black Hawk Down) were almost exclusively SPECOPS missions.
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