Help! Struggling ...

[fairylightqueen]

20a (8) Plane? No, it's undergoing repair in shed.
27a (10) In story, returning evil's held to be perfect.
29a (10) Unyielding regarding missing holy period?
8d (10) Shiny rubbish bins discovered to contain goods? Quite the opposite.
11d (7-5) Quickly leave after defeat yet to be arranged.

Thank you in anticipation of your brilliance!

[donny48]

licketly split

[Mamyalynne]

11 Lickety split

[Captain2]

8 Glittering

[donny48]

8 glittering

[Captain2]

29 Relentless

[donny48]

29 relentless

[Mamyalynne]

29 Relentless

[Captain2]

27 Infallible

[Captain2]

20 Jet-tis-on

[Mamyalynne]

20 Jettison

[donny48]

20 jettison

[donny48]

27 infallible

[donny48]

20 (plane) jet + anagram of no & its
jettison = shed
27 (in story) in fable with lli (backwards ill [ evil])inside
infallible = perfect
29 (regarding)re + lent (holy period) + less (missing)
relentless = Unyielding
11 (defeat)lick + l(leave) + anagram of yet
Quickly = Lickety split

[Mamyalynne]

slightly disagree with 11

Defeat - Lick
Yet, anag - ety
Quickly leave - Split

[Mamyalynne]

sorry - leave - split

Quickly is definition