underfire
Cosmo, where are you flying RNP DEP?
Just to clarify where RNP and ANP comes into the equation. The FMC will show you what lateral value you have to comply with to fly RNAV-X/P-RNAV. Should these values be exceeded you will get the "UNABLE REQD NAV PERF-RNP" message. In the respective QRH checklist you will find the following option:
On a procedure or airway without an RNP alerting requirement:
Verify position.
...hence, you won't need to do a raw data check as long as the FMC is not alerting you to do so, and even if a VOR is part of your departure, as such you can fly it in LNAV and do not need to tune it and fly it in VOR/LOC....
....which was in response to Captaintcas:
How else to follow a VOR? Do you go in heading sel.?! And follow up raw data?!
Lnav?! Then you risk map shift and input error at low altitude or terrain
On the LEGS PAGE of the FMC at the bottom left, you can keep an eye on your navigation performance written as RNP/ACTUAL, hence:
For departure, cruise and arrival, we rely on Require Navigation Performance vs. Actual Navigation Performance and associated caution messages (without raw data cross check).
Yes, Boeing doesn't really care about the definitions of RNAV-X/B-RNAV/P-RNAV vs. RNP (it seems). Should we as pilots care? As long as we know what lateral limits are applicable and appropriate response should they be exceeded.