Big cheese? Awful, beginning to crumble and flipping go off (8)
I believe the answer is:
Here is my best explanation:
'big cheese?' is the definition.
'awful beginning to crumble and flipping go off' is the subsidiary indication.
'awful' becomes 'dire' ('dire' can be a synonym of 'awful'**).
'beginning to' indicates taking the first letters.
'and' is a charade indicator (letters next to each other).
'flipping' is a reversal indicator.
'go off' becomes 'rot' (I've seen this before).
The first letter of 'crumble' is 'c'.
'rot' backwards is 'tor'.
(Other definitions for director that I've seen before include "one on board", "Senior person in a firm, executive or non-executive", "Controller of production or member of a board", "Company board member", "Business manager or film maker", "This person could be on board or in theatre", "Big cheese", "leader", "Creditor made to create film or play" and "Record it (anag.)".)