I've never been to Duncan Airport, so I'm not sure about the situation, but at most airports there's something called a "circuit" that aircraft follow. Generally speaking, it's a rectangle about 3 km long and 1 km wide, with the runway in the middle of one of the long sides (and it can flip locations depending on the wind direction). At an airport without a control tower (that's most airports), everybody flies the same circuit for the sake of safety. They'll be at about 1,000 ft above ground level on the long side that doesn't have the runway (what we call the "downwind" side). It's important that everyone use the same circuit to avoid the risk of midair collisions, and to provide an orderly way for multiple aircraft to approach the airport and land (it's sort-of the flying equivalent of a four-way stop, where there's no light, but all the drivers know and follow the same rules).
So if you live under the circuit, unfortunately, there will be many aircraft flying repeatedly at 1,000 ft above your house on days when the wind favours the corresponding runway. That information is public (there are even often different zoning regulations near an airport), but most realtors either suppress it or outright lie about it to make house sales, then any home owners who don't like airport operations are left feeling angry and duped once the realtor has run off with the sales commission.
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