Never seen Pallid before so armed with camera I rattled off as many shots as I was able to take. It showed at close range over the rooftops and School off New Street but the light was tragic and constant drizzle not helping either.
A few looks at it through the bins made me feel it was paler than I'd expect a Common Swift to look and that upper wing coverts were boldly fringed pale making the inner wing look scaly. The overall upper tones of the bird seeming fairly concolourous with no obvious saddle. Away from the upper wing I did not particularly notice a scaly look to the body plumage of notice any underwing features. Flight appeared more relaxed and lethargic, it appeared a bulky bird too.
Photos now processed show that no plumage features can be assessed safely from them. However, the shape and structure of the bird does make it look interesting. A few features to concentrate on are the relative length of t4 and t5, the broadness of the wing towards the tip, the bulk of the body and size of the bill. T4 & T5 seem fairly similar in length as expected for Pallid. Wings do appear broad towards the tip which is good for Pallid. The body appears fairly heavy which is good for Pallid. And the bill appears very prominent and big which is good for Pallid. Whether the structural appearance of this bird is enough to ID safely I'm not sure. Barry Stewart shares my sentiments and I thank him for his comments. We agree from the photos it probably is a Pallid but without the support of plumage features fear it might not be enough to be certain. Perhaps others might like to comment?