I think there’s a bombing range out at Fort Indiantown Gap. They’ll use regional airports like Lancaster for T&G’s so that the pilots can keep their proficiency up.
I used to live in Brickerville and later over in Northern York County. I used to see the A-10’s swooping over Ski Roundtop. I presumed that they were shooting approaches over at New Cumberland Airport or possibly Harrisburg International where I used to see KC-135’s & Ospreys.
That’s my thought. I used to live in the Lititz area and still see them flying in the neighborhood, from time to time. I’ve also seen Navy training planes of some sort, smaller Cessna types with US Navy markings, doing touch and goes at LNS.