Main body of an aircraft (8)
I believe the answer is:
fuselage
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">main body of an aircraft</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for fuselage that I've seen before include "Aircraft's body" , "part of aircraft" , "is often up in the air" , "Central body of an aeroplane" , "part of plane" .)