I'm no expert at flight shots but here goes ...
I find the hardest bit is keeping the bird centrally in the frame so I don't lose focus. Some birds are very considerate and fly in fairly straight lines. Others tend to change direction without warning
Your lens should be fine. What you may find is that, because the camera is mostly metering a fairly bright sky, it will result in the bird being an under-exposed silouette. I dial in some +ve EV compensation to overcome this. You'll need to experiment to find an EV value which works for your camera/lens combination.
Hope this helps.