sensitive areas, or through difficult terrain. History RNP procedures were introduced in the PANS-OPS (ICAO Doc 8168), which became applicable in 1998. These RNP procedures were the predecessor of the current PBN concept, whereby the performance for operation on the route is defined (in lieu of flight elements such as flyover procedures, variability in flight paths, and added airspace buffer), but they resulted in no significant design advantages. As a result, there was a lack of benefits to the user community and little or no implementation. In 1996, Alaska Airlines became the first airline in the world to utilize an RNP approach with its approach down the Gastineau Channel into Juneau, Alaska. Alaska Airlines Captain Steve Fulton and Captain Hal Anderson developed more than 30 RNP approaches for the airline's Alaska operations. In 2005, Alaska Airlines became the first airline to utilize RNP approaches into Reagan National Airport to avoid congestion. In April 2009, Alaska Airlines became the first airline to gain approval from the FAA to validate their own RNP approaches. On 6 April 2010, Southwest Airlines converted to RNP. Since 2009, regulators in Perú, Chile, and Ecuador have deployed more than 25 RNP AR approach procedures, designed in conjunction with LAN Airlines. Benefits included reduction in greenhouse gases emissions and improved accessibility to airports located on mountainous terrain. The use of RNP AR approaches in Cusco, near Machu Picchu, has reduced cancellations due to foul weather by 60 percent on flights operated by LAN. In October 2011 Boeing, Lion Air, and the Indonesian Directorate General of Civil Aviation, performed validation flights to test tailor-made Required Navigation Performance Authorization Required (RNP AR) procedures at two terrain-challenged airports, Ambon and Manado, Indonesia as pioneering the use of RNP precision navigation technology in South Asia. Established on RNP approaches Inspired by a 2011 white paper, the ICAO published in November 2018 the Established on RNP-Authorization Required (EoR) standard to reduce separation for parallel runways, improving traffic flow while reducing noise, emissions and distance flown. Similar to Denver International, it was implemented in over three years at Calgary International, lowering the final approach requirement from , before reaching trajectory-based operations. As 40% of aircraft arriving are equipped to fly RNP-AR, 3,000 RNP-AR approaches per month would save , and associated with continuous descent, would reduce greenhouse gases emissions by 2,500 metric tons in the first year. Description The current specific requirements of