Spectator 2636 - Happy Ever After By Cheesecracker

[Matakari]

Good morning, a felicitous offering from CheeseCracker this week. Help
with the following to take me through to the theme would be appreciated.
Many thanks in advance!

35a European industrial gear grabs earth, perhaps (6) : ?LAN??
3d Helpless Australian city girl (5) : A?EL?   ( ADELE )
22d Bird in flight around India, migrating when it’s cold (9) : ???T?GI??
32d Bacterium stage suppresses resistance (5) : ??R??

[OftPuzzled]

35a Insert E (European) into a word for industrical gear, to give a category to which Earth belongs.

3d is correct. ADEL(aid)E

22d Your G is incorrect.

32d is an abbreviated word for a sort of bacteria, often associated with a sore throat. The word for stage - think feet.

[Boethius]

I'd be grateful for help when you work out the theme, Matakari. I am totally and utterly at sea with this one. Everyone else seems to be sailing on!

[OftPuzzled]

The crossword's 'three quartets' relate to the three individual words of the crossword's title. Once the rest of the crossword is filled in, there are 26 unchecked letters which correspond to 'ask.engineering-academy.gov.uk'. Most can be entered by process of elimation. 

[Matakari]

Many thanks, OftPuzzled, for the hints and parsing! Number 22
is still evading me, though.
22d Bird in flight around India, migrating when it’s cold (9) : ???T?RI??

[Neveracrossword]

Matakari, as you're still struggling...

22 Wintering, migrating when it's cold.  The I for India goes inside Tern, bird, with Wing being glight.

[JJ109]

Wintering (migrating when it is cold)

Tern (bird) around I(ndia), inside "wing" (flight)

[Matakari]

Many thanks, NACW and JJ109, I'm satisfied with the answers to the clues now and am having a look at the Unclueds which seem a bit challenging.

[Neveracrossword]

Thanks, Matakari. As well as the thematic help given on this thread, there are other bits dotted around AB. The theme shouldn't be too challenging for someone of your experience - you've been tackling this puzzle for over 15 years now!

[Boethius]

Thank you, OftPuzzled. I'll puzzle on.

[Matakari]

Boethius, I am still working on the thematic aspect of the puzzle and as soon as I make a breakthrough I'd be happy to give you a hint.

[Boethius]

Many thanks, Matakari. I'm on the verge of throwing in the towel!

[Neveracrossword]

Boethius, for each of the words in the title, you need to find 4 that could join them. In each quartet, two words go before the theme word, two after - along the lines of Banana Split or Top Banana. 

In this week's puzzle, 25 D was reasonably easy to spot - it goes before a Theme word. Some are definitely harder to track down, but ticking off the letters mentioned in the preamble helped me enormously. 

[Boethius]

Thank you, Neveracrossword.