FAA Aircraft Dispatcher (ADX)Navigation and ATCMedium
A dispatcher is comparing conventional RNAV with Required Navigation Performance (RNP). What key capability distinguishes an RNP system from a standard RNAV system?
- ARNP systems include onboard performance monitoring and alerting capability
- BRNP systems require ground-based DME updating while RNAV systems do not
- CRNP systems are only used for oceanic navigation, while RNAV is used domestically
- DRNP systems eliminate the need for a published missed approach procedure
Show answer & explanationAnswer & explanation
Correct answer: A. RNP systems include onboard performance monitoring and alerting capability
RNP is RNAV with the added requirement of onboard performance monitoring and alerting, allowing the aircraft to verify it is meeting the specified navigation accuracy and alert the crew if it is not. This distinguishes RNP from conventional RNAV, which lacks this self-monitoring capability.
Why the other options are wrong
- B. Neither RNAV nor RNP inherently requires DME updating; many systems use GPS/INS.
- C. Both RNP and RNAV are used in oceanic and domestic operations.
- D. Missed approach procedures are still required and published for RNP approaches.
RNP vs RNAV
RNP (Required Navigation Performance) is RNAV with added onboard monitoring and alerting of navigation accuracy performance.
- RNAV = area navigation using various sensors (GPS, DME/DME, INS)
- RNP = RNAV plus onboard performance monitoring and alerting
- RNP value (e.g., RNP 0.3) specifies required lateral accuracy in nm
- Used for approaches, departures, and enroute operations requiring higher precision
Memory trick: 'RNP watches itself' — self-monitoring accuracy