Yeah, important to note that some unattended machines still allow Chip+Signature cards even though they try to use Chip+PIN if available. So you want to be sure that you're using a terminal that requires a PIN before making strong conclusions. (Ideally you'd find a terminal that required offline Chip+PIN since that's the mode that the fewest cards support, but this is probably harder to tell.)

I'm quite certain that the AA Exec card does not support Chip+PIN. In general, US cards do NOT support Chip+PIN, so it's generally reasonable to assume that US-issued cards are Chip+Signature only unless you have relatively good reason to believe otherwise. Maybe this will change one day, but it's a fair statement of the state of play right now.