I was one of the first to arrive on site. Stayed an hour and a half.
At 930am the swift sp flew towards me and over my head. Looked good for pallid. Pale throat and dark outer primaries compared to inner wing. Others had good views with the sun out and relatively low in the sky.
This led to the consensus that the bird was a pallid swift with only a few disagreeing. As time went on more and more doubted the pallid ID. Sometimes the bird would look relatively pale, at other times darker.
My own opinion went from probable to possible pallid swift and finally to an ID of common swift.
Pictures 15 to 18 show the underwing. It was not possible to see enough detail on camera screens.
Picture 16, to my mind the wings look good for pallid but the throat patch looks to small
Picture 15 the lower wing is at a different angle to the sunlight, suggesting common to me
Picture 17 common swift
Never mind the bird appearing paler on some views in the field than others, the angle of the bird and shadowing can be seen on the photographs.
My initial belief the bird was a pallid swift, based on the wing pattern, never mind the head and throat pattern and eye, was misplaced now photographs are available to study at leisure.
Common swift for me, then