And Mode S has serious implications for TCAS systems (preventing air to air collisions.)
Extremely bad to be messing with those frequencies. Potentially catastrophic.
If someone with a hobby electronics kit can cause that much damage, the system needs to change. Hobby projects like this can help expose the serious flaws in aircraft control, making us all safer.
Security by obscurity is no security at all. Security by hoping people don't do bad things is even worse.
Just because you can do something does not mean its ok to do.
And we have a lot of controls around this! Congrats! You've discovered airline security!
> expected to not operate equipment on wrong frequencies that interfere with others
If I can build a small electronic device, that goes through no controls, and can cause catastrophic damage, that is a HUGE problem.
> Just because you can do something does not mean its ok to do.
lol, you missed the point. If it's that easy to do something, the system needs to change.
However, any deterioration in that redundancy is considered a serious safety risk and immediate action is usually taken.
Bottom line: The high redundancy is there to prevent accidents, however any idiot who compromises that redundancy deserves to learn an expensive lesson.
But since you're disabling safety equipment or their redundancies, in practise it's rightfully treated as harshly as it is. TCAS almost never activates in practise but if your HAM radio jams it and a crash happens... You disabled that redundancy to prevent accidents.
Damn, this sounds like a huge risk. Kinda like the risk I mentioned in my first comment.
This system relies on safety be reliability / availability. All of the operating parameters are public, to prevent anyone from accidentally interfering with these systems. They are not designed against adversarial attacks, and really with radio systems. It is very hard to defend against jamming attacks. Doing so successfully makes the system a lot more complicated. More importantly, doing so successfully makes the system use much more bandwidth.
Bandwidth is actually really scarce. If you start doing defensive stuff, then more and more frequencies get used, and you end up with everyone screaming over each other just to be able to add all the required error correction. That is why we decided to coordinate on frequency allocation. It prevents a tragedy of the commons. As a side effect, it also means transmit power can be lower. This allows you to operate more systems in the same area without interfering.
Now, this does leave a somewhat fragile system. Because jamming (and other attacks) are not mitigated by the system. But this is an acceptable price to pay to actually allow people to use radio communication.
Besides, jamming attacks have an interesting downside. They are somewhat easy to track down. The higher level attacks can be defeated by cryptography. There is a mid-level of smart jamming, that attacks the low level protocols with more than just power. These require significant effort to develop though. And military hardware tends to have mitigations against this sort of thing. A sufficiently sophisticated attacker could disrupt civil systems, but to what gain?
> Now, this does leave a somewhat fragile system
Thank you for reiterating my point. If such a system is not designed to stop adversarial attacks, and is a fragile system, something needs to change.
I appreciate you trying to explain why it's fragile, but it doesn't negate the risk.