These are the types of images I look to capture.
Besides the obvious need to be able to get in flight photographs the real issue is distance.
The bird needs to be in the ‘sweet spot’ of a long lens, and have the light right for that spot. Both of which you have no technical control over.
For these images it was position and luck. Luck was the bird not too close. Position was a clear open view from right to left.
The first shot in a series is a miss, a focus shot. I better have more clear opportunities panning with the moving bird or the sequence is all misses (the lens used needs a to shift focus fast).
These were shot using a Sigma 150-600 C lens. The distance was also right for my Tamron 18-400. However the focus speed is not near Sigma so I most likely would have missed these.
In fairness to the Tamron to reacquire focus the search must be from 18 – 400 or until it grabs the subject. A much longer search than Sigma.