This is a bonus cache that you can find when you successfuly complete the Nelson Aviation Advenure Lab.
When you have the collected the required information information, you can find the cache a short drive (or walk or ride) away at:
S 41 17.ABB E 173 13.CDE
The cache is a bison micro container with log only. Bring your own writing device. No need to detach from where it is.