Hey, they're not bad shots...just if the light isn't as strong, keep in mind the shutter will be a bit slower, and get your camera on something solid, like the roof of a car or a fencepost, etc...
I have a nice shot of a Sikorsky that was taking off from Redding Airport while I was waiting for the Collings Foundation to land, back in June...I'll post that over in my photograph thread, if you want to compare!