Across
Clumsy person, terribly old, boarding helicopter (10)
Argument suitable to be backed with force (4)
River adopted by ray — and another fish (5)
Good Yankee soldiers overturned plot primarily endangering aircraft (9)
I haven't cracked this one yet — but Times for the Times have:
G + Y + OR backwards + PLAN + E[ndangering].
Churchy NW town originally advertised in sprawling italics (14)
I haven't cracked this one yet — but Times for the Times have:
ECCLES + anagram of ITALICS around A[dvertised]. The Eccles Goon must come from somewhere – my Ninja Turtle of the day.
Female with pride in Sir Tristram's birthplace, it's said (7)
Family eating pigmeat finally suffers wind in Egypt (7)
I haven't cracked this one yet — but Times for the Times have:
K(HAM, [suffer]S)IN.
Complex man's big wordbook I dine over (7)
I haven't cracked this one yet — but Times for the Times have:
O.E.D. + I + SUP backwards.
Take part in dog show, perhaps, but arrive without dog? (7)
I haven't cracked this one yet — but Times for the Times have:
COM(PET)E.
Simple rustics in America kept by state money (7,7)
Performing stage work in simple key, including tango (9)
I haven't cracked this one yet — but Times for the Times have:
OPERA (T) IN G. I don’t think operas actually have keys – maybe we should ask Jeremy?
Bracing air a specified person associated with Australia (5)
Fell making twitcher's shelter (4)
Recently recruited compiler digesting Liberal bulletin (10)
I haven't cracked this one yet — but Times for the Times have:
NEW S(L)ETTER.
Down
Youngster going over a sugar-producing island (4)
Caught in excessively noisy environment, become dull (9)
I haven't cracked this one yet — but Times for the Times have:
OVER (C) LOUD.
She helped mate malamutes initially, rocking Herts town (5,9)
I haven't cracked this one yet — but Times for the Times have:
Anagram of SHE HELPED MATE M[alamutes]. Solvable even by those who have never heard of it, like me.
Winged horse, — quiet. say, like you and me (7)
Set aside weapon in English rescue boat (7)
OT patriarch's account supporting another (5)
I haven't cracked this one yet — but Times for the Times have:
ISA + A/C. Another thing we don’t have in the U.S.
Self-employed person in country with right to catch fish (10)
I haven't cracked this one yet — but Times for the Times have:
FR(EEL)ANCE.
Work on the school map somehow: it's used to examine pupils (14)
Perplex clergy, producing cleaning requisite (10)
Grim job, getting supporter on board! (9)
Second row about Kentucky's visible horizon (7)
Hawks catching last of sluggish birds (7)
I haven't cracked this one yet — but Times for the Times have:
C([sluggis]H)OUGHS.
Stand erect and extremely unbowed outside animal enclosure (5)
I haven't cracked this one yet — but Times for the Times have:
U(PEN)D, where the enclosing letters come from U[nbowe]D.
Muntjac, possibly, bringing up grass (4)
I haven't cracked this one yet — but Times for the Times have:
REED upside down. Muntjac is another NHO.
Type letters or click words in the clue