NAV CANADA is planning updates for some arrival procedures at YYC. The changes affect a specific type of approach - known as Required Navigation Performance (RNP) procedures. RNP allows an aircraft to fly a precise route that is often shorter and quieter compared to conventional approaches.
This type of procedure has been available at the airport since 2016. NAV CANADA has identified opportunities to enhance safety while providing new options for pilots to employ an RNP approach when arriving from certain directions.
Also, YYC will be the first location in the world to implement a new international standard that will improve how all traffic is integrated and enable increased usage of RNP, with associated environmental benefits.
What is Required Navigational Performance?
RNP is part of a family of technologies that lever the capabilities of modern flight management systems and the Global Navigation Satellite System for safer and more efficient navigation. RNP is increasingly being used to provide safe and accurate arrival routes to busy airports; it is also a significant piece of the technology toolkit being utilized to meet commitments made by the global aviation industry to reduce greenhouse gas emissions.
The benefits of RNP include operational predictability, environmental impact reductions and the use of Continuous Descent Operations (CDO) which enables a quieter approach. A little less than half the flights to Calgary International are currently equipped to fly RNP approaches.
Safety Enhancements (Implementation: September 2018)
Adjustments to crossover segments and new tangents were designed to increase situational awareness and allow for earlier recognition of risk. The common “arc” for a portion of crossovers creates a late detection if there is an error in the arrival runway selected by the pilot as the point of divergence occurs late in the approach phase (see figure 1). This affects a small subset of traffic and requires a minor adjustment to the location of divergence. The new crossovers will enhance safety while new tangents will provide additional opportunities to use quieter CDO approaches.
Figure 1 - Adjustments to RNPs
The following maps show the changes on a runway by runway basis. A sample of flight tracks as flown are shown in light blue; current RNP segments are shown in blue while new segments are shown in yellow (crossovers) and pink (tangents).
Figure 2 - RNPs Runway 35R and 35L
Figure 3 - RNPs Runways 17R and 17L
Figure 4 - RNP Runway 29
New International Criteria (Implementation: Late 2018)
Established on RNP (EoR) is a new International Civil Aviation Organization (ICAO) separation standard that leverages the predictability of RNP to improve how traffic is integrated. Today, aircraft that are landing on parallel runways must be separated by either three nautical miles laterally or 1,000 feet vertically until they are “established on final” (i.e. lined up with the runway and being guided by the Instrument Landing System). As a result, some aircraft operating to parallel runways must be pushed to a lower altitude or employ a longer trajectory to provide safe separation as they head towards parallel runways. This can create more noise and increase emissions as a result of low altitude level flying and longer routings. With the new EoR standard, aircraft will be considered “established on final” as soon as they commence the RNP procedure, before turning on to final. In some instances, it will reduce the need to push aircraft to lower altitudes for sequencing reasons while providing more opportunities to benefit from quieter, continuous descent operations in a parallel runway environment. YYC will be the first airport in Canada and one of the first in the world to utilize the new ICAO standard to improve how traffic is integrated.
Watch the video below, produced prior to the initial launch of RNP at YYC, to learn more about RNP.