CACHE IS NOT AT POSTED COORDINATES, but it is a good place to start
I found out about this place just this summer. This new area is great for watching planes in all directions. The other viewing area, off Post road, is an awful place to watch planes come and go, ever since they added all kinds of fences and barriers.
Viewing area is open 7 am to 9 pm.
Use the information sign at the posted coordinate's to get the needed answer's to the final location. The Final location can be found at: N44 AA.BBB, W093 CC.DDD
Update info 10/23:
I've updated the puzzle due to the signage has changed. If you have the old numbers, that should still work. The final location has not changed, even though I've updated the coordinates. You can use the QR code on the new sign to see what the old sign looked like.
CC = The general aviation airplane's cabin length divided by 2.
DDD = The cargo plane's overall length in feet plus 785.
AA = The commercial airplane's top speed minus 500.
BBB = The military airplane's top speed plus 647.
The final is 1.5/1.5. The cache will be an easy find once you get to the final GZ