Photographing birds in flight is getting much easier with the new cameras.
Not to long ago I purchased the Nikon D 500. It has proven to be one of the best Nikon cameras I have ever owned for birds in flight.
Setting the focusing to 153 focus points I never missed a photo that was not sharp. The two Goldeneyes above were against the snow, but the camera never had a problem locking on.
1/2000 sec at F 6.3 ISO 2000