I assume you mean it being slightly overexposed and blowing the sky? I am not familiar with your camera, so don't know what the fastest shutter speed is, but if it is only 1/1000 sec, which is what the picture was taken at, it's not fast enough.
Shooting in Av mode, as you were, and at a selected aperture of 2.8, which is going to let a lot of light in on a bright sunny day, the camera is going to need to be able to pick a suitably fast shutter speed to get the exposure right. If 1/1000 is indeed the best your camera can do, you were asking it to do the impossible when you selected such a wide aperture.