Specialist Tully (SPOILERS)
When I saw his reactions regarding the missing plane and the people on board, I thought that he must have someone he knows/cares for on that plane.
First -
Seeing and hearing Frank talk, and then a certain look he gave I thought:
"hmmm... maybe they're going for the same-sex couple angle"
Frank and Tully are to be man and man, but alas I was mistaken.
Then -
I thought:
"well... maybe he's Tony's dad, and they were going to see him. But, why is Jennifer hitting on the Air Marshall? Weird."
Nope, that wasn't it either.
In the end it would seem that Tully was not related to any of the passengers on that flight.