Trip by air (6)
I believe the answer is:
flight
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">trip by air</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for flight that I've seen before include "Exodus" , "Voyage of an aircraft" , "Tail of an arrow or dart" , "Journey by air" , "The feathers on a dart or arrow" .)