Gps
The US Air Force requires IFR flights to have an alternate when;
8.4.2.1.1. All compatible approaches require radar.
8.4.2.1.2. GPS is the only available NAVAID.
8.4.2.1.3. Required NAVAIDs are unmonitored.
8.4.2.1.4. When the destination has no weather reporting capability.
Now radar can go U/S, Unmonitored naviads can be U/S and one may not know, having no weather reports is not great when IFR. All good reasons for having an alternate.
However, GPS?
Isn't that the navaid that it owned and operated by the US military who have access to all it's bells and whistles?
Isn't it the most accurate and reliable bit of equipment that even a simple UK PPL can use for navigation - in fact if IO540's and other's comments are to be believed it is always the best thing available.
Then why does the mighty US Air Force put restrictions on it's use above the restriction thay place on a simple VOR or ILS?
Ideas anyone?
Regards,
DFC