In article , Ron Natalie wrote:

Your information on RAIM is wrong. What is unique about the RAIM used in IFR
approved GPS's is not that it determines when the satellite geometry is giving you
an error NOW, but computes if it will fail while during the expected duration of flying
an instrument approach.

That's RAIM *prediction*. RAIM is very capable of failing during an approach if
you don't check the prediction ahead of time, at least on our Garmin 430.

I don't know what John's information on RAIM is, since it will be two or three
hours before his books is downloaded.

Regards,

Mike