It depends. We now have this little thing called the Internet, and you can quickly learn a ton of things on it. Even if you just learn a few points and without all the details, that's still better than nothing and at least a starting point for further study, if needed.

And it depends on the direction of the answers too.

For example I think most autoland still require some amount of visibility a few seconds before touchdown, and the pilots are supposed to go around if they do not have it. Plus, I believe planes also use a radio altimeter while landing. But I don't believe they use GPS for the final approach.

So you might put a plane in a difficult position with that kind of attack, but not necessarily making it crash. And there are probably more easy ways to do more damage.