57B: RNP APPROACHES Flashcards
How is RNP APCH different from RNP AR APCH?
According to ICAO Doc 9613 Performance Based Navigation Manual (PBN Manual), there are two types of navigation specifications for approach operations:
(i) RNP approach (RNP APCH) and (ii) RNP authorisation required approach (RNP AR APCH) e.g.
Kathmandu RNP Rwy 02 AR.
Special aircraft and aircrew authorization are required from regulatory authorities for RNP-AR Approaches.
IndiGo is currently not approved to conduct RNP-AR Approaches.
Where can we check the GPS RAIM NOTAMs for Outages?
GPS RAIM NOTAMs are provided under UNCATEGORISED section of the FIR NOTAMS as part of the Briefing Folder.
How and when is a RAIM check performed?
Flight crew are to refer to NOTAMs at the dispatch stage to check RAIM. In flight, there is no need to check the PREDICTIVE GPS page for a RAIM check and the GPS RAIM check via the NOTAMs suffices. The approach maybe commenced as long as GPS PRIMARY is available on at least one side.
Additionally, in case of E/TSO-C129a Class A1 receivers installed on all IndiGo A320 aircrafts, an auto check is performed 2 NM before FDP. If RAIM is lost after FDP it continues to provide navigation for up to 5 minutes before triggering RAIM LOST indications.
Do all RNP APCHs need to be Early Stabilized?
Decelerated Approach technique is preferred for RNP Approaches flown using FINAL APP
Early Stabilized Approach technique is mandatory when FPA (Vertically Selected) guidance is used.
What is the maximum acceptable discrepancy between altimeters?
Maximum tolerance accepted during Preliminary Cockpit Preparation:
±20 ft between both PFDs And depending on the aircraft configuration:
±100 ft between ISIS Land PFDs, or
±300 ft between mechanical standby altimeter and PFDs.
Maximum acceptable discrepancy between altimeters prior to commencing RNP Approach is 100 ft.
Can we accept DIRECT-TO Intermediate Fix (IF) when cleared by ATC?
DIR-TO Intermediate Fix (IF) is permitted provided the resulting track change at IF does not exceed 45 degrees
When does one press the APPR pb on FCU?
Press the APPR pb when all of the following conditions are satisfied:
- The aircraft is cleared for approach
- TO waypoint is the Final Descent Point.
If APPR pb is pressed earlier, FINAL APP mode may engage. As a consequence, resulting speed and altitude management in FINAL APP may be inappropriate before FDP.
Is the Distance Height check referenced to VOR DME or Runway Threshold?
The Distance Height check for RNP APCHs are always referenced to Runway Threshold. This can be read of the top right of ND after crossing FDP (TO WPT).
Alternately use the R/W Threshold that has been inserted on PROG Page for position monitoring during Approach Preparation.
Can we plan and execute NP APCHs into all airfields for which Approach Plates are available in Jeppesen and the corresponding approach is correctly coded in the FMS NAV Database?
Few of the RNP APCHs included in the FMS NAV Database are for trial purposes. List of the same are available in C-NOTAM 04 series (NAV DATABASE BULLETIN). Pilots are informed not to select the mentioned approaches.
Minimum Equipment Required to Start an RNP APCH states a requirement for 01 FMS & 01 GPS. However, the IndiGo RNP APCH Briefing Guide lists the need for 02 FMS & 02 GPS receivers as part of the “Pre-Flight Checks”. Why the discrepancy?
Disregard the requirement of 02 FMS & 02 GPS receivers mentioned in the briefing guide. It will be corrected in the next edition.
Can the AP/FDs be kept on below the minima on a RNP approach?
The AP must be must be disconnected by AP Minimum Use Height or MAP, whichever is higher. For Minimum Use Height of the AP, Refer to LIM-AFS-10 Autopilot Function
