These changes are found in para 6.7 in PANS ATM (ICAO Doc 4444) and supported by the Manual on Simultaneous Operations on Parallel or Near-Parallel Instrument Runways (SOIR) Edition 2 (ICAO Doc 9643); the latter provides further explanation and implementation guidance.
The following notes focus on Independent Parallel Approach operations (Mode 1), however, the reader is to refer to the two documents above for definitive requirements for these types of operation.
Historically, parallel approach operations were only supported by ILS and MLS and could only be initiated once the aircraft were established on the final approach track or course. In addition, radar vectoring was the only way to establish the aircraft on that final approach path. The PANS ATM amendment now allows a published PBN approach procedure as an alternative method to intercept the final approach track.
In addition, the table below details the different options to support parallel approaches:
The ICAO Separation and Airspace Safety Panel (SASP) recognised that if RNP AR APCH performance was safe enough to support operations into terrain challenged aerodromes, it would equally be safe enough to support independent parallel approach operations (Mode 1) to runways spaced more than 1035m (3400 ft) apart.
Where all parallel approach operations using a precision approach (PA) landing system (ILS, MLS or GLS) require the aircraft conducting parallel approach operations to be established on the final approach course or track before the No Transgression Zone (NTZ) can be invoked and the 3NM or 1000’ separation standard be discontinued, the Established on RNP AR APCH operation provides an alternative approach. Established on RNP AR APCH, sometimes incorrectly referred to as EoR, permits the NTZ to be invoked and the 3NM/1000’ separation discontinued prior to the aircraft rolling out on the final approach track.
Established on RNP AR APCH is a RNP AR approach designed with RF legs and with a specific waypoint in excess of 3NM from the other approach path at which point the aircraft flying the RNP AR approach will be ‘established’ on the procedure, the standard separation will be discontinued. The aircraft will be left to follow the cleared procedure and no further normal ATC instructions will be given; however, an emergency ‘breakout’ instruction will be issued by the monitoring controller to the RNP AR aircraft if the aircraft on the other approach path deviates off its approach path and transgresses into the NTZ.
Although the diagram above shows a RNP AR Approach against an ILS, Established on RNP AR APCH can be applied on both runways as it is in Calgary Canada; more information can be found here. In addition, although the diagram shows a ‘wrap around’ 180 RF leg, the amount of turn can be is at the procedure designer’s discretion.
Further information on ‘Established on RNP AR APCH’ can be found in PANS ATM (ICAO Doc 4444) Chapter 6, para 6.7.3.5 and further detailed in Appendix A of the Manual on Simultaneous Operations on Parallel or Near-Parallel Instrument Runways (SOIR) (ICAO Doc 9643, Ed 2).