When I say windy, I mean inside 100+mph prop-wash, shooting from an open cockpit aircraft. The camera is an Olympus C-765 UltraZoom, which features a retracting zoom lens. It may be that manually controlling the focus fixes this problem, but I'd like to know what is going on and if there may be another possible mitigation.
It takes time to focus, sometimes a small fraction of the second, sometimes more. If your camera is moving or your subject is moving during that time then any camera will have trouble focusing. In your case, your camera is moving fast and winds add to that motion, making it even more difficult.
Focusing on most cameras which are not DSLRs, like yours, is done by contrast-detection. Contrast is measured at the AF point(s) and the lens is moved. The process is repeated until the point of highest contrast is found. If what is in the AF point(s) keeps changing (because of motion) then the camera has trouble completing this process and gives up.
The solution is to use manual focus (MF) but it is not available with all cameras. If not, you may have 'Infinity' or 'Pan' focus modes. The former gives you more depth of field by setting focus to the hyperfocal distance. Sometimes, those modes are not explicit but part of a Scene mode such as Landscape, the camera manual will tell how focus is locked for particular scene modes.
I do a lot of air to air photography, and even with a good DSLR like the Nikon D300 and a 16-85 lens, I always avoid to put the camera into the prop wash. It could easily take the camera off of your hands (I have seen this happen to a friend), and, in any case, the wind is so strong that you will never get a sharp picture. The plane you are flying surely has a wind screen, even a small one, and that should be sufficient to "hide" your camera and avoid most of the draft while you're taking pictures. Using a medium range zoom lens should provide enough depth of field so that you do not need to constantly change the focusing, even manually. Using a long tele/zoom lens would be different, but who needs that kind of lend up there ?… Just one last advice: NEVER un-buckle while you're flying ! Some strong turbulences and you could be out of your seat before you know it !!! :)
Sometimes in windy scenarios, you may get your lens dusty, so checkout if you have dirt or dust in your lens.