A publication of the National Air Traffic Controllers Association
Issue link: http://natca.uberflip.com/i/961329
This issue has not been resolved and we were slated to meet wit h AJV on March 26 . PBN to ILS Update In order to provide information, you first must understand what occurred. On March 27, 2017 A LPA national voiced concern over the removal of VNAV as a minimum requirement for future RNAV approach procedures. Specific issues noted included Flight Crew workload increases during Closely Spaced Parallel Operations (CSPO), the risk of un - stabilized app roaches will increase, contradiction to the premise that all runways will have a vertical guidance to every runway end. (Recent reference to this paradigm is noted in the PARC produced PBN NAS Strategy 2016.), increased probability of Class B incursions du e to lack of vertical guidance, previous studies that addressed operations using localizer only or LNAV only did not address the risk of Controlled Flight into Terrain (CFIT), and aforementioned studies were in a "simulator setting" and did not accurately reflect what a pilot would experience in actual, real world operations. Mitigations were suggested (inferred) such as; consider further proliferation of ATC Minimum Safe Altitude Warning Systems (MSAW) to include altitudes normally inhibited today due to nuisance alerts, terrain avoidance warning systems are not available during non - - ‐ precision approaches (Specifically glideslope deviation alerts, ATC monitoring only provides lateral guidance for collision),flight crews operating non VNAV equipped aircraft prefer vertically guided procedures over non - - ‐ vertically guided procedures, and majority of mainline airlines have VNAV capability (RJ aircraft are LNAV only). So, what happens now? In response to the concerns, NextGen Integration Performance Based Navigation Working Group (NIWG PBN WG) is looking into the issues, developing a data driven dialogue to address concerns, which includes asking for objective basis for challenges noted. While this activity is going on, the de sire is to keep moving forward and not bring the evolution of PBN to a halt. Are there other means to provide vertical guidance while flying RNAV EoR style procedures? Of course, RNP to ILS… On October 17 AVS ‐ 1 requested PARC look into RNP to ILS procedur es and operations in order to leverage RNAV procedures to an ILS approach. This was given to the PARC Navigation Working Group (PARC NAV WG) through a letter, which basically stated, "based on recent concerns raised by industry regarding pilot workload and the availability of vertical guidance when conducting simultaneous approaches, we request that the PARC Navigation Working Group review operational considerations that mitigate operational risk to ensure aircraft can safely transition from RNP to xLS g uidance. Factors that may be elevated include, but are not limited to, the availability and necessity of vertical guidance, pilot workload required to transfer between guidance modes, potential benefits of a longer straight final approach segment, and risks associated with dual/parallel operations." Moving forward, the PARC NAV WG will review and provide a ToR for PARC SG which led to an Action Team and we just me t for the first time on Feb. 21 in Atlanta . Speed Cancellation Guidance Recent concerns ha ve been raised by controllers pertaining to current guidance in the 7110.65 regarding the issue of speed termination when a Descend Via (DV) clearance is issued and the STAR has no speed restrictions and pilots whose guidance is different within the Airmen 's Information Manual (AIM). Based on the guidance contained within