On 17/04/2021 20:41, Harry Bloomfield wrote:
It must have done at my count 40 very tight circles, before I got bored
watching. It had landing lights on, around 10 miles from the airport and
had white lights flashing on wing tips.

Visibility strobes.

I couldn't see any navigation
lights.

Not necessarily on during daylight.

What might that have been doing?

Waiting at a holding point for permission to join the landing circuit.

--
Colin Bignell