(Please post comments on ONLY the picture quiz hereinbelow. To post comments on the crossword puzzle, please click here.) An enjoyable puzzle from Tuesday regular Phssthpok, with a couple at the end taking slightly longer. Thanks to Phssthpok. Definitions are underlined in the clues.
Across
1 Way out of wind tunnel (8)
LOOPHOLE : LOOP(to wind round, making a loop) + HOLE(an area hollowed out in something solid;a tunnel). Good misdirection.
5 Caught help stealing last of liqueur (6)
CASSIS : C(abbrev. for “caught” in cricket) + “assist”(to help) minus its last letter(… stealing last of).
Defn: … made from blackcurrants.
10 Posts editorials (7)
COLUMNS : Double defn.
11 The French dress has space to stretch (7)
LEGROOM : LE(French for “the”) + GROOM(to dress;to smarten one’s or another’s appearance).
12 Crease new bedding (5)
LINEN : LINE(a crease, say, in material, or even on the cricket pitch) + N(abbrev. for “new”).
13 Whisk tea beggar adulterated (3-6)
EGG-BEATER : Anagram of(adulterated) TEA BEGGAR.
14 A gem found by a police searchlight? (5-7)
BOBBY-DAZZLER : BOBBY(a British police officer) DAZZLER(a searchlight, perhaps one used by the police).
Answer: One who is excellent, originally from northern English dialect.
18 While undergoing treatment, given bad drug for being unfriendly (12)
INHOSPITABLE : { [IN HOSPITAL]( undergoing medical treatment) containing(While …, given) B(abbrev. for “bad”) } + E(abbrev. for the drug Ecastasy).
21 Circle date for invading and finding capacity (9)
BANDWIDTH : BAND(a circular piece of material) + { D(abbrev. for “date”) contained in(for invading) WITH(and;together) }.
Defn: … of an electronic communication channel, in terms of the amount of data that can be passed along it in a given period of time.
23 Imprisoning grandmother: that is foolish (5)
INANE : NAN(term for one’s grandmother) contained in(Imprisoning …) IE(abbrev. for the Latin “id est”;that is).
24 Rat’s one who might formulate this? (7)
TREASON : Anagram of(who might formulate) RAT’S ONE.
Defn: … is what a rat might formulate;devise or develop. A WIWD (wordplay intertwined with definition) clue.
25 Go wild in Turin or party (3,4)
RUN RIOT : Anagram of(party) TURIN OR.
26 Article on curse lacks a solution (6)
ANSWER : AN(in grammar, an indefinite article) plus(on) “swear”(to curse) minus(lacks) “a”.
27 New chemical not left out for technician (8)
MECHANIC : Anagram of(out) [ N(abbrev. for “new”) + “chemical ” minus(not) “l”(abbrev. for “left”) ].
Down
1 Pub gets final place setting (6)
LOCALE : LOCAL(the pub near your home or place of work) plus(gets) last letter of(final …) “place “.
2 During tea, nothing was bowled at Oval (6)
OBLONG : “oolong”(a dark Chinese tea that has been partly fermented before drying) with an inner(During …) “o”(letter representing zero;nothing) replaced by(was) “b”(abbrev. for “bowled” in cricket).
Answer: Having an elongated shape, starting from a square or a circle, the former being the more commonly used. A nice cricketing surface.
3 Titanic found by old Unesco or Greenpeace, possibly, in dip (9)
HUMONGOUS : [O(abbrev. for “old”) + NGO(abbrev. for “non-governmental organisation”, examples of which;possibly are Unesco and Greenpeace) ] contained in(in) HUMUS(one of the alternative spellings of “hummus”, a food dip popular in the Middle East).
4 The leaning tower of Pisa? (6,8)
LISTED BUILDING : Cryptic defn: Reference to the list;the leaning to one side of that famous building, and to the Statutory List of Buildings of Special Architectural or Historic Interest in the UK of conserved buildings which cannot be demolished, or even altered, without special permission from the relevant authorities. And that tower will surely be on the Italian equivalent of the list, or something like it.
6 Scum or gas mostly contaminated beer (5)
ALGAE : “gas ” minus its last letter(mostly) contained in(contaminated) ALE(beer).
7 Bound to fill branch with business jargon (4,4)
SHOP TALK : HOP(to bound;to leap) contained in(to fill) STALK(a branch on a plant or tree).
8 Hat for South American tailless marsupial after dark (8)
SOMBRERO : “roo”(short for “kangaroo”, the Australian marsupial) placed below(after, in a down clue) SOMBRE(dark;gloomy). Another good misdirection, as South America has its share of marsupials.
9 In vain, try to sell a drug after being affected by anaesthetic (4,1,4,5)
FLOG A DEAD HORSE : FLOG(try to sell, perhaps even, a lame or dead horse) + A + [ HORSE(slang for the drug heroin) placed below(after, in a down clue) DEAD(to the world after being given a general anaesthetic) ].
15 In Brazil, lion threatened one coming after many others (9)
ZILLIONTH : Hidden in(In) “Brazil, lion threatened “.
Defn: … , viz. after a zillion minus one, a huge but unspecified number.
16 Spies thrash army for bread (8)
CIABATTA : CIA(abbrev. for US spy agency) + BAT(to thrash;to beat, with a, well, bat) + T.A.(abbrev. for the British military arm).
17 Wonder if aristocrat‘s game hid in lake (8)
CHINLESS : CHESS(the board game, not only for aristos) containing(hid) [IN + L(abbrev. for “lake”) ].
Answer: When used together with “wonder”, a derogatory term for one, especially an upper-class person, who lacks strength of character, ie. is weak or stupid, or both. The receding chin trademark is a genetic abnormality brought about by inbreeding, which is reputedly practised by the upper classes, including royalty.
19 From country in Africa, get a change to good or evil (6)
MALIGN : “Malian”(describing one from the African country of Mali) with the 2nd “a” replaced by(get … change to …) “g”(abbrev. for “good”).
Defn. and Answer: Malevolent.
20 Frenetic hospital psychiatric treatment requires intensive care (6)
HECTIC : H(abbrev. for “hospital”) + ECT(abbrev. for “electroconvulsive therapy”, formerly known as electroshock treatment, usually used as a last resort treatment of severe psychiatric illnesses) plus(requires) IC(abbrev. for “intensive care”).
22 Don’t use murder (5)
WASTE : Double defn: 1st: Let go into disuse; and 2nd: Criminal slang for “to murder”.
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The following pictures have unidentified links to the puzzle.

(Please post comments on ONLY the picture quiz hereinbelow. To post comments on the crossword puzzle, please click here.)
Thanks for the blog and bonus picture puzzle scchua.
First pic is the Sombrero Galaxy (8d). Third is synchronised swimming which includes the egg beater kick (13a). I recognise the other pics, but the links to the puzzle escape me (unless the last one is loosely linked to 27a mechanic).
Hi Steve, right on Pic1 SOMBRERO and Pic3 EGGBEATER.
Pic2 An ancient Roman helmet, called a CASSIS, the Latin word for helmet.
Pic4 Horned helmet shells, of the genus CASSIS.
Pic5 Ronaldinho, exponent of the SOMBRERO flick, a football move where the player flicks the ball from the ground to over his head, hence the name.
Pic6 ALGAE is used to produce biofuels, including biodiesel.