There's a fantastic book, "Clashes" by Marshall Michell all about this subject, which I can highly recommend. All about the air war in Vietnam.

https://www.amazon.com/Clashes-Combat-North-Vietnam-1965-197...

From my reading of the excellent book Clashes: Air Combat over North Vietnam, 1965-1972 (http://www.amazon.com/Clashes-Combat-North-Vietnam-1965-1972...) that would imply your father was fighting over South Vietnam (or perhaps to the west), but, hmmm, it didn't mention F-111 missions at all. For the big operations up north, the Air Force used up its F-105 inventory, and had to switch to their own version of the Navy's (spit) F-4.

Ah, per Wikipedia the F-111 was employed, but I can see why it wasn't covered in book, it was ideally employed as a low level terrain following penetrator, so it would not be a part of the big daytime flocks of birds that the NVA were be able to follow and vector their Migs to for one pass attacks. So not relevant to a book focused on air combat per se.

Heh, love the anecdote about the Edsel. The Official Story, on Wikipedia at least, is that he saved Ford not by pushing it, but by killing it, but I have my doubts, everything he touched after that turned to shit, including his disastrous tenure at the World Bank where he destroyed untold agricultural systems in the Third World....