Question

How do I write this sentence using an active voice?

Some of us had been permitted to stay on the deck for the fresh air

Answer 1

Who is allowing "us" to stay on deck? Make that the subject of the sentence. I.e. "The captain permitted us to stay on deck for the fresh air"

Answer 2

Active voice?

Hmmmmmmm that's a difficult one(!) Active's when you change the Subject and the Person around, but like there's no specific person :/

I'd say something like:

We were permitted to stay on the deck for fresh air
or
Some of us stayed on the deck for fresh air, as we were permitted(?)