When I was a lot younger…in the mid '80's... I was traveling with my son from Lewistown heading to Billings. There's a long slope from the top of the plateau north of Roundup down to the bridge over the Musselshell river. A B-52…probably an H model was sneaking down the river valley. Out of Minot, they were trying to sneak over to Great Falls to see if it was possible to surprise the Missile base there. They lifted up over the bridge and dropped back to the valley floor…it was pretty impressive. I had no idea a '52 could be that quite or fly that slow.
That's where I got the idea for the A-10's in the valley. I figure if a B-52 can be that quiet it's got to be possible to do the same with an A-10.