FLR-PSA,
Any half way smart person can get the plans off the internet and go to Radio Shack and for measly money make a unit that will make it very hard for any airport to accept traffic. The only reason it is not done is that you paint a target on yourself by sending out so much signal. If them dumbass terrorists ever figure it out, baghdad airport will be a only operate during the day and your flying manual. You also won't be talking to the tower either.
A cargo UAV? All alone out over the ocean? Golly, sounds like you will generate a whole new bread of pirates that will hyjack the signal and direct the UAV to land at some remote island where it's cargo is offloaded and then send it back on its merry way. That sounds really brilliant.
If man can make it, man can break it. That is gospel in the electronics industry.
