It's already been proven that cars with Onstar can be hacked to slam the brakes, accelerate, and that the Airbus family has ground control over rides in case of hijacking or pilot incapacitation.
It's not new news that there is only so many frequency bands that electronics work on, that any phone can be hacked to transmit or a ground signal can transmit to an airliner the code necessary to screw things up on the deck.
It might have been what happened on 447.
The answer is simple, if you hire pilots that are competent, that you can trust, then you don't have to rely on gear that can be compromised so easily.