Date: 201603
Local time of day: 0001-0600
Location: BWI.Airport, MD
Flight conditions: VMC
Light: Night
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Human factors: Workload
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew FLC Overrode Automation
Contributing factors: Chart Or Publication; Human Factors; Airspace Structure
Primary problem: Chart Or Publication

Narrative: Based on a past constructive phone conversation with our ATC Liaison Chairman; listening to an argument between a pilot and Houston air traffic controller pertaining to a descend via clearance plus having just flown the ANTHM2 RNAV arrival into BWI; it has finally prompted [me] to write this [report]. I find it fascinating in our industry how change causes the pendulum to always swing from one extreme to another thus constantly unbalancing the equation. The sole purpose of this [report] is not to look at any one specific SID or STAR but to raise awareness from a process and global perspective. In this instance I would recommend viewing the complex nature of the ANTHM 2 RNAV arrival BWI as an example.It appears much of the focus during the implementation phase of RNAV procedures has been on automation and efficiency with possibly some of the weight being lifted from the ATC folks. However; from a pilot's perspective; the result has been a heavier burden and workload in the cockpit. The lateral guidance associated with the SIDS and STARS appears to be a positive improvement; but on the other hand; the vertical and speed portion of the procedure is dysfunctional in many cases.From a safety and process perspective; every altitude restriction and speed change has to be perceived as a threat. Having been a past Safety representative; our task was to minimize the threat environment and mitigate risk; not to increase it exponentially. The design and development of the RNAV procedures is heavily dependent on automation; which in some cases fails to meet the criteria; requiring pilot direct intervention.For example; at times the FMGC will plan to cross a required fix 1;000 [to] 2;000 feet high; leaving it in the hands of the pilots to identify and correct the error prior to failure. In many cases; there is much confusion amongst the pilots and controllers once any parameter associated with a descend via clearance has been modified; thus once again creating another type of threat.Unfortunately our world is dynamic but the design of these procedures is typically best built for standard conditions. Coming from a person who is extremely process oriented; I would classify the RNAV SID's and especially STAR's to be over designed. I realize there has been a lot invested into these procedures and they are here to stay; but please take a moment to honestly look at some of the more complex STAR's and count the number of threats; keeping in mind the high velocity of the aircraft and the mental gymnastics we do on a routine basis to meet the assigned parameters. Just because the aircraft FMGC is programed to descend via an automated vertical flight path; doesn't provide the pilots with immunity; which suggests simpler is better!In referencing our operating priorities; this is a complete process failure. The operating priorities are inversely applied. For example; the SIDS [and] STARS do benefit efficiency from what I have been told; however; definitely limit our ability to affect On-time performance; reduce passenger comfort with the constant use of speed brakes; plus frequent pitch changes and most of all; sacrifices the almighty safety aspect just based on threat environment alone.  Besides issues associated with actually flying the RNAV procedures; charting is not standardized; thus creating another classification of threat. The shear mass of information we must cross check or enter from the charts leaves room for error. Technology is a wonderful thing; but only when used within its proper capacity! In this case; I would strongly suggest rebalancing the equation. If SAFETY is truly our top priority as an airline and more importantly as an industry; then this issue needs to be addressed in a proactive manner! Don't forget the old adage; FLY THE AIRPLANE!!!!! Thanks for your time and consideration! Hopefully these comments will stimulate a thought process and gain some traction towards re-analyzing our RNAV threat environment; as we shouldn't have to apply the CRM/ Threat and Error Management (TEM) Model on a descend via clearance.




Synopsis: A pilot makes commentary as to the challenges with RNAV descents for aircrews.