A publication of the National Air Traffic Controllers Association
Issue link: http://natca.uberflip.com/i/603672
This GBAS approach uses this concept on a single runway and removes the lateral component but uses a displaced thresho ld. It d oes need a crosswind component. Pilots in a German experiment rejected this concept on parallel operations when being the trailing aircraft on a parallel runway because the threshold was displaced to stay above the wake turbulence and they didn't like the shortened runway. Analysis was performed for displaced thresh olds of 3500, 4500 and 5500 ft. Analysis uses current implemented GBAS performance (mimicking ILS CAT I) . o For the 5500 ft displaced threshold scenario (most significant wake mitiga tion but sacrifices > 1⁄2 of runway length) o H - H separation could be reduced from 4NM to 3.5 NM o H - L separation could be reduced from 5 to 4 NM o Only 3300 ft of landing runway would remain for the aircraft landing the displaced threshold (1200 ft displaced ILS) o The final separation reduction may be less depending on NGE analysis results o ANG may have sufficient data to proceed based on the OGE analysis results alone · Comments (combination of FAA and Volpe input) o As the Threshold S tagger increases the likelihoods decrease o However, the decrease is not enough to compensate the severity to consider it no worse than today o If 3 NM type of separation is desired for L behind H, then the analysis does not support that amount of redu ction. o L behind L shows possible reduction to 1.5NM (same as 7110.308) o If half runway can be "given up", would it be advantageous to incorporate that into WTMA - P/.308 (i.e., essentially HALS/DTOP) · Boeing/Honeywell assumed separation reducti ons are far greater than wake encounter risk analysis shows · PARC Report o Assumptions on fleet mix equipage assume most optimistic scenario, and projections have gone down since that report o Airport equipage is also an issue (i.e., beyond EWR) o Assumptions on separation reduction are not known by the Wake Office · Existing operational risks are still open – no documentation received by FAA to date o Pilot acceptance of displaced threshold approaches o Can lead aircraft safely and r epeatedly turn off the runway prior to the trailing aircraft touching down on the same runway · PBN STATs - Since 2009, an additional 208 RNAV Standard Terminal Arrival (STAR) procedures were implemented, resulting in a total of 308 RNAV STARs throug hout the NAS. Also since 2009, 240 RNAV Standard Instrument Departure (SID) procedures were implemented, bringing the total in the NAS to 415. For the 77 Aviation System Performance Metrics (ASPM77) airports, 80% now have RNAV SIDs or STARs. Recent procedu re implementations for large airport Metroplexes (e.g., Houston, North Texas, Washington , D . C . , and Northern California) benefitted from using the collaborative Metroplex process, working across stakeholders to ensure that effective and efficient procedures a re developed on an expedited timeline. The conventional Jet route and Victor