Looked like a military personel carrier just above the trees but wasn't moving.

My husband and I were driving from Jasper, Mo to Carthage,Mo to go grocery shopping.  
About 2 1/2-3 miles out of town we saw an aircraft that looked like a military personel carrier right above the trees.  It was a dull green color. It was not moving or making any noise. We could see the propellers but they were not moving either.  I don't know if this was a UFO or what it was.
We looked for ropes thinking maybe it was some life size military craft balloon but there were no ropes. 
It was the weirdest thing we have ever seen. We kept driving and got our groceries. When we returned it was gone. 
I swear that this is no joke. We would really like to know what this could have been. 
Can anyone help?
Witness indicates that the date of the sighting is approximate.  We have assigned an arbitrary date.  PD