But that's the question: How? The spoofed messages is easy to believe, but these message systems (ADS-B and ACARS) do not interface with the FMS and thus an at

But that's the question: How? The spoofed messages is easy to believe, but these message systems (ADS-B and ACARS) do not interface with the FMS and thus an attacker should not be able to take over the FMS in this way. So some critical piece of information is missing.