In-flight announcement, for short (3)
I believe the answer is:
eta
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">in-flight announcement for short</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for eta that I've seen before include "Militant Basque organisation - Greek letter" , "Letter from Doris" , "when it might reach us?" , "Greek letter - Basque nationalist movement" , "indicating when flight is due" .)