No Hootie, they would just radio "send help"
They use the phonetic alphabet whenever they need to spell something out. It's spoken, not written. For example, in the Navy there is an airplane called an "E-2" and one called a "C-2". Since E and C are similar sounding, to avoid confusion the person on the radio would refer to one as an "Echo - 2" and one as a "Charlie - 2".
Basically, the phonetic alphabet is just a precaution to make sure that letters aren't mistaken for other letters.
Plus, it sounds cool! lol