This seemed fairly straightforward for a Saturday. I finished comfortably over lunch. There was a good helping of clever wordplay, and lots of gravy. I liked 12, 17 and 27ac, and 16, 19 and 24 dn. Does anyone want to nominate their clue of the day?
Thanks to the setter for a very enjoyable puzzle.
Clues are in blue, with definitions underlined. Answers are in BOLD CAPS, then wordplay. (ABC*) means 'anagram of ABC'. Deletions are in [square brackets].
1 Tot's initial reprimand for crying (7)
TEARFUL: T[ot], EARFUL.
5 Blimps regularly track aircraft (7)
BIPLANE: Odd letters of “blimps” are B-I-P-, then LANE.
9 Brief all guards in Washington, first line of defence (7,4)
CURTAIN WALL: CURT (brief), then ALL “guarding” IN WA. Chambers gives “curtain wall” as a non-loadbearing one. Not sure why that’s the first line of defence. Perhaps the Wikipedia version is clearer: A curtain wall system is an outer covering of a building in which the outer walls are non-structural, utilized to keep the weather out and the occupants in.
10 Stop someone telling joke (3)
GAG: double definition.
11 Ran out of drink and cursed, half-cut (6)
LAPSED: LAP (drink), [cur]SED.
12 Officer pulling wings off lady beetle and termite (8)
ADJUTANT: AD (lady, minus “wings”), JUT (beetle, as in “beetle-browed”), ANT.
14 Volatile vet is fearless and forceful (4-9)
SELF-ASSERTIVE: anagram (“volatile”) of (VET IS FEARLESS*).
17 Anxiety about millions leaving huge country (13)
CONSTERNATION: C (about), [m]ONSTER (huge, minus M for millions), NATION.
21 Oddly neglected fiances kiss saucy amateur (8)
INEXPERT: even letters of “fiancés” are -I-N-E, then X (kiss), PERT.
23 Quiet old man hiding in an under-fire vessel (3-3)
ASH-PAN: SH (quiet please, this is a library) and PA, all “hiding in” AN. Clever definition.
25 Badly want to lose weight (3)
ILL: [w]ILL (want), losing W (weight). The definition is “badly”, as in “ill/badly treated”.
26 Father got us bananas, much in demand (6-5)
SOUGHT-AFTER: anagram (“bananas”) of (FATHER GOT US*).
27 Man perhaps stops crazy fool (7)
MISLEAD: ISLE (… of Man, perhaps), inside MAD.
28 Sanctimonious, before experiencing pain (7)
PREACHY: PRE, ACHY.
1 Grab food and beer, heading off (6)
TACKLE: TACK, [a]LE.
2 Poor sap treated suitably (7)
APROPOS: anagram (“treated”) of (POOR SAP*).
3 Order gal to feel pulse (9)
FLAGEOLET: anagram (“order”) of (GAL TO FEEL*). Not a pulse I knew, I confess.
4 Feline couplings can be heard (4)
LYNX: sounds like LINKS.
5 Make revolting violet-coloured biscuit (6,4)
BRANDY SNAP: BRAND (make, of car for example), reversal (“revolting”) of PANSY (violet-coloured).
6 Maud sheds clothes after endless lager and spicy rice (5)
PILAU: PIL[s] (“endless” lager), then [m]AU[d] (“without her clothes”).
7 Answer four consecutive letters about a new currency (7)
AFGHANI: A (answer), then FGHI (consecutive letters) around the letter A and N (new).
8 Without leaders we might see an age of maturity (8)
EIGHTEEN: drop the first letter of each word, giving [w]E, [m]IGHT, [s]EE, [a]N.
13 Pretty good routine that holds attractions (10)
FAIRGROUND: FAIR (pretty), G (good), ROUND (routine).
15 Restore control over country (9)
REINSTATE: REIN, STATE.
16 Mostly working with university, in one's element (8)
ACTINIUM: ACTIN[g] (working, “mostly”), then U (university) in I’M (one is).
18 Winds up unnecessary contracts (7)
19 Advancing relatives turn up gaping and twitching (7)
NEPOTIC: NEPO (OPEN=gaping, “turned up”), then TIC (twitching).
20 Greener gym conserves power (6)
ENERGY: hidden answer.
22 Dads ultimately get some stick (5)
PASTE: PAS (dads), [ge]T, [som]E.
24 Tea party excluding Bohemian fellow
CHAP: CHA (tea), then P[arty].