Tilt, then tilt upward, front of plane (7)
I believe the answer is:
cockpit
'front of plane' is the definition.
(I've seen this before)
'tilt then tilt upward' is the wordplay.
'tilt' becomes 'cock' (cocking is a kind of tilting).
'then' says to put letters next to each other.
'tilt' becomes 'tip' (synonyms).
'upward' shows that the letters should be reversed in order (in a down clue, letters go up).
'tip' back-to-front is 'pit'.
'cock'+'pit'='COCKPIT'
(Other definitions for cockpit that I've seen before include "position on board" , "Main venue" , "Compartment for aircraft pilot" , "flying from here" , "not suitable for a hen party" .)