When people fear boarding a plane because of a recent terrorist attack, while ignoring the fact that the likelihood of experiencing a terrorist attack while aboard a plane is extremely small, this heuristic is at work?

It is small only if you are not involved in such an incident. If you are, then it is extremely large. 

First  hand experience is what I would give as the answer. If I am wrong leave a message for me, and I will have my answer deleted. 

I’d say e civil liberties