The PROC button toggles the screen between its current state and a display of the currently
selected approach procedure. If no procedure has been selected, a procedure can be chosen
for the airport in the flight plan using this function.

Processing the approach is a two-step procedure. The first click of the PROC button produces a screen that looks like the one at the top. This allows you to select the approach you want from the list of available approaches. Once selected, it can be either loaded or activated. Loading allows the existing GPS navigation functions to continue, but makes the approach available with only two button presses. Activation marks the IAP or another fix you may have indicated as the "direct to" navigation point. Once there, the GPS will sequence the approach as each fix is passed.