Thud Ridge

The plane is passing just south of Phuc Yen. Phuc Yen was a major NV airfield during the war, and more heavily defended than any other place in history. Primary attack aircraft in and around Hanoi were the F-105 Thunderchief, nicknamed the Thud by its pilots.

Thud Ridge is the ridge line just north of Phuc Yen--it extends NW to SE and almost points to Hanoi. Thud pilots called it that because they would use it to mask themselves against radar guided Surface to Air Missiles (SAMs) and AAA during ingress and egress to/from targets in and around Hanoi. If they flew low north of the ridge, the radar couldn't see them and SAMs as well as search radars could lose tracking.

You can see Thud Ridge looming just below the wingtip. Pilots would call it 'Going Downtown' when they had a strike mission to an area in or around Hanoi.

Republic made the F-105 and also the P-47 Thunderbolt and the A-10 Thunderbolt II (Warthog). They made very durable airplanes. The guys who flew the Thud had balls of steel. Many of their missions were around Hanoi, because the Thud carried lots of ordnance, had a gun, and could go faster than anything down low. They also used them as Wild Weasels--aircraft and aircrew specially made and trained to go after the SAMs. It was very dangerous work and Thud pilots suffered heavy losses. There's a great article that tells just one story here:
http://www.talkingproud.us/Military/Military/Military/LastCombatMissionSparks.html

I'm glad I got to see it finally.