No 11577, Thursday 17 Dec 2015, Arden

ACROSS
1   Stairs causing stampede (6) FLIGHT [DD]
4   Roam around bringing in delivery to the Royal residence... (8) BALMORAL {ROAM}* in {BALL}

9   ...return of the wicked Queen — one will experience again (6) RELIVE {RE}{LIVE} <=
10 No more running commentaries on the meaning (8) SEMANTIC  ComMeNTArIES*
12 He will obstruct by American writ (8) MANDAMUS {MAN}{DAM}{US}
13 Worker gets sick and he gets to keep the property (6) BAILEE {AIL} in {BEE}
15 Control panels — so drab (12) SWITCHBOARDS {SO+DRAB}*
18 Back with hundred and one — as good as any (6,2,4) SECOND TO NONE {SECOND} {TO N}{ONE}
21 Money problem, both leaders missing (6) ROUBLE ? tROUBLE
22 Status Quo? No way with line of descent (8) AGNATION stAGNATION
24 Shifting base upon court order (8) SUBPOENA*
25 Quietly the animal will attack (6) POUNCE {P}{OUNCE}
26 Song and shadow boxing will end before long (8) DOGGEREL {DOG}{b...nG{ERE}{wilL}
27 Mobs clash, largely with stones (6) ASHLAR [T]

DOWN
1   First and second in the wild (8) FOREMOST {FORE{MO}ST}
2   Badly disillusioned dudes leave state (8) IILINOIS dISILLusIONed*
3   Crazy how ace resolves a problem (4,1,5,5) HAVE A SCREW LOOSE*
5   Help and take a chance with it (4) ABET {A}{BET}
6   The fundamental part of a meal, perhaps (4,3,8) MEAT AND POTATOES [C&DD]
7   Scare with a toy (6) RATTLE [DD]
8   Protection essential for a toady (6) LACKEY {LAC}{KEY}
11 Dish to be sent up by Wellington (3,4) GUM BOOT {GUM<=} BOOT Anno pending (Addendum - {GUM BO}{OT<=} - See comments)

14 Dressing players on time (7) BANDAGE {BAND}{AGE}
16 Academic from Milano, it once promoted (8) NOTIONAL [T<=]
17 Perhaps Rudolf's in control — there's rush to go up (8) REINDEER {REIN}{DEER<=}

19 Opened up — After middle of month send name out (6) PRISED ? (Addendum - {aPRIl}{SEnD} - See comments)
20 Spooner's back squeeze is all gas (6) HUMBUG {(-b+h)HUM}{(-h+b)BUG}
23 Bet and run in the middle (4) ANTE Anno pending (Addendum - cANTEr - See comments)

GRID