Not that old & have not had problems with them before, creaks/cracking sound is loud & bloody annoying.
Have squirted it with gt85 but still does it. Anyone found a remedy?

If I remember right there’s a little allen screw under the nose which needed a little tighten on mine.

Fill the cavities where rails with glue or silicone putty or something.

This will be temporary fix (works couple of months) but I haven’t found other options. All of my Bel-Airs (3!) have started creaking at some point.

Is it at the seat clamp, or where the rails enter the saddle body?

If 1, clean, grease and tighten.
If 2, GT85, allow to dry, and if it still squeaks, silicone it.

Failing that, you’ll have to live with it – it’s annoying, but not structural.

have you tried standing up?

Fairy liquid in the rail sockets.

I used to have a bel air that creaked. After trying numerous keyboard warrior remedies I realised the seat tube had cracked