Ever since I was in the United States Air Force I have been fascinated by flight and, in particular, the flight of high performance and stealth aircraft. I had "top secret" clearance but even that was not enough for me to be allowed to know if Area 51 really existed. Though the government won't confirm it, most of us do believe that Area 51 does exist as a secret airbase in a corner of Nevada where super secret flight activity occurs. I have some old Air Force buddies who live near Tonapah who keep their eyes on the skies for unusual activity.
Today I was called by one of these buddies who had sighted an unusual aircraft heading NE at an extraordinary rate of speed. Inexplicably (or perhaps not), it was transmitting unencrypted data such that we were able to track it from its origin at N 37o 18.5891', W 115o 38.0593' to where the data transmission abruptly ceased at N 33o 13.6841', W 25o 08.6640'. The aircraft's travel conformed strictly to a route of great circle navigation.
I was fascinated because the flight path took this aircraft directly over Traverse City. As you can see above, I took a photo of the aircraft as it passed overhead. Below is as a map of the flight path (as we knew it). Your guess is as good as mine as to what this aircraft was really up to.
I have hidden a geocache directly beneath the flight path where this aircraft had traveled precisely 1/3 of its total distance.
To locate this geocache, you will need to perform great circle navigation calculations. These are conveniently provided by Ed Williams in his Great Circle Calculator. Great circle routes are the shortest routes of navigating between points on the surface of the earth. This is not entirely intuitive as we all know that the shortest distance between two points is a straight line. However, to travel a straight line between any two distant points on a spheroid body like the earth would involve digging a substantial tunnel! Great circles, on the other hand, involve arcs of circles lying vertically above such straight lines in a plane passing through the center of the earth. In most cases great circles have true courses that vary from point to point. GPS receivers provide great circle navigation. For a more thorough understanding of great circle navigation, see Williams' Aviation Formulary.
The coordinates that introduce this webpage are not for the cache itself. Instead, they are for a convenient parking area. If you need some help, feel free to contact Whitard
With the coordinates in hand this will be an easy find. Have fun!