Having spent an eternity on this, still can't see these:-
38 Down - "Vile knitwear one drops in chute" (4,6) -A-E -U-P-R
("JUMPER" is in there somewhere, I imagine)
43 Down - "Malicious flying bomb to be destroyed" (8) -I-E-I-H
(VIXENISH? - Is there a flying bomb called a vixen?)
50 Down - "Lots of deliveries during term for boarders?" (5) O-E-S
(Surely "OVERS", but where do "boarders" come into the
reckoning? I can't find anything to tie in "boarders" with "overs"