"circling in" is a correct and usable phrase in written English.
It means to hover or rotate around something or someone. Example: The vultures were circling in, waiting for their next meal to die.
Before long, children were circling in the saloon.
Too bad nobody saw the sharks circling in the harbor.
Maybe he can be kept circling in a garden.
Then, she nervously thought she saw something else circling in the air.
This advertisement is not for me, but for the neighbouring kites, circling in further skies.
But surely even ballet neophytes felt the ghosts circling in "Liebeslieder Walzer," which followed his speech.
WINFIELD, Mo .— First came the urgent news from a volunteer circling in a helicopter.
The helicopter had been circling in support of a US military operation taking place below.
The hunt proceeded systematically, the boat circling in an ever-widening spiral.
Watching from rooftops, circling in cruisers and patrolling on foot, dozens of officers kept a watchful eye.
He's pointing up at a tiny black dot circling in the sky, his binoculars pressed tightly against his eyes.
