Thanks for the detailed explanation of the MANPADS. But I may be of service here. I was in the navy at the time and a submarine sailor aboard a Los Angeles class fast attack boat.
We don't have anti-aircraft missiles aboard fast attack submarines. Plus would be pretty hard to track an airliner with sonar.
So you can scratch submarine off the list too.
Thanks. I wasn’t sure if fast-attack had anti-aircraft missiles or not.