Bladeangle, after reading your & Glekichi's remarks about late model GPS receivers, I did some reading. I learned something.
(I use a C129 Universal receiver myself.)
In SBAS-enabled units, which includes Universal SCN 1000-series software,
RAIM predictions are not automatic prior to an approach. I guess you know that you are much less likely to get a RAIM outage with an SBAS-enabled receiver, because it has a better GPS decoding algorithm (less likely to suffer from rain fade etc) and because the Japanese SBAS geostationary satellite is permanently in view, giving you an extra GPS satellite in view at all times in Australia. (Can't use it for SBAS, can use it as an extra GPS transmitter.)
So if your SOP requires you to have an in-flight RAIM prediction, and you have an SBAS-enabled receiver, you will need to do it manually. My operator does not require it for C129 or for 145/146 receivers, as the NAIPS notam system meets all practical requirements. But SOPs differ, as we all know!
If your SOPs just say that RAIM must be available, same as the flight test requirement, like I said earlier, it IS available provided you don't have a warning, INTEG light, etc.
Correct, for all receivers. Do CASA regs require an in-flight prediction? I don't think so, although goodness knows I'm no expert on this particular country's regulations. They require a prediction before flight, and actual RAIM availability on the approach.
AFAIK.
I've had RAIM warnings on approach even though both NAIPS and the in-flight prediction were ok.
I've seen a receiver give the ok even though NAIPS said there would be a RAIM hole (approach not flown in that case.)
I've had NAIPS say ok, only to have the receiver (briefly) predict no RAIM at the FAF, then flown the approach successfully.
You'll have to excuse my belief that manual receiver predictions are not worth the time it takes to perform them!
One error above, regarding loss of RAIM on the approach in the so-called 5 minute "coasting" segment inside the FAF. It's a bit off the topic.
RAIM warnings are generated if a) RAIM is available and b) integrity limits are greater than required. These will always be presented to the pilot immediately, requiring a missed approach. Where a "
loss of RAIM" occurs due to seeing only 4 satellites, the LOI alert may be inhibited for 5 minutes. Depending on the statistical integrity of the fix in other circumstances, "Loss of RAIM" may or may not be presented to the pilot in this 5 minute segment.