I am studying for my CFII check-ride and I was wondering to know why SIDs and STARs are not RNP 1 but RNAV 1?
Let's start with the following two definitions
RNP - Required Navigation Performance: It's a PBN navigation method/specification in which the airplane achieves an specified accuracy (RNP 1, RNP 2, etc) the a 95 % of the flight time. It has an onboard monitoring system that alerts the pilot when the integrity is loss. Examples of Equipments that are able to perform RNP 1, RNP2, etc are IFR GPS receivers with RAIM or WAAS (integrity monitor).
RNAV - Area Navigation: As we know, FAA uses RNAV in chart tittles only to determine Area Navigation. But RNAV it is also a PBN method/specification in which the airplane achieves an specified accuracy (RNAV 1, RNAV 2, etc) the a 95 % of the flight time. The only difference is that the aircraft won't alert the pilot when the integrity of the system is loss. I've never used an RNAV system without integrity monitor, I guess that DME/DME/IRU is wan of those. Is an IFR GPS with RAIM capability lost considered an RNAV system without integrity monitor?
The final and most important question is: On SIDs and STARs, Why is it not required to have a system that monitors the integrity of the equipment and alert the pilot if the accuracy can't be determined? Are pilots supposed to monitor the integrity of the systems by themselves? How?
I found the following on AC 90-100A CHG2 8. RNAV SYSTEM APPROVAL PROCESS (b)(1)
"For procedures requiring GPS and/or aircraft approvals requiring GPS, if the navigation system does not automatically alert the flightcrew of a loss of GPS, the operator must develop procedures to verify correct GPS operation"