Flight Crew Air Transport Pilot (ATP)
Workload; Situational Awareness; Human-Machine Interface; Distraction
Deviation - Altitude Crossing Restriction Not Met
General Work Refused
Procedure; Aircraft; Human Factors
I wrote an ASAP a few months ago on this subject; and I am writing again; because I cannot over stress the importance of this subject. We were cleared to descend via the BOOSH RNAV STAR into STL in our CRJ900. Prior to the flight; we had spent approximately 15 to 20 minutes reviewing and planning the very complex arrival. Enroute; we reviewed the arrival again for several minutes prior to being cleared to 'descend via' the STAR. During the arrival; I was very busy monitoring the progress of the very complex arrival; getting things on the aircraft ready for approach and landing; making and getting calls from the cabin; calling ops; getting ATIS; programming the ACARS and FMS; setting speeds; briefing the approach; and the list continues. During that time; I felt it necessary to prompt my First Officer several times on restrictions I felt he was verging on busting (or setting himself up to be unable to make another subsequent restriction) had I not said something. This caused many interruptions to my other duties; which made them take MUCH longer than they normally would; and kept me from giving the necessary attention to the arrival that it requires. I don't particularly fault my First Officer for being behind the airplane. I more fault the difficulty of the complying with the arrival at all in this aircraft. What would have happened on this flight; if my First Officer; who is new to the CRJ and is still getting used to it; was with a sub-par Captain? You can bet there would have been at least one; if not multiple busts on this flight. Because of the complexity of the situation; it is certainly possible that I; too; may not have caught one or more restrictions; as I was; again; distracted by other high priority tasks. I don't believe we violated any restrictions. However; I cannot say with certainty that we did not. As we neared 10;000 FT; I felt it necessary to advise ATC that we may have difficulty meeting some of the subsequent restrictions. The Controller immediately gave us a heading and altitude which took pretty much all of the heavy workload off of us. A intense workload I don't feel we should have had in the first place. I DO NOT believe that we should be flying these VERY COMPLEX arrivals in our aircraft. The CRJ is simply not equipped for them. They are so complex they require nearly 100% attention by both pilots during nearly the entire arrival. I understand that the arrivals may work well enough with an aircraft with autothrottles and autopilot coupled VNAV. We have neither which GREATLY increases our workload. My VERY STRONG recommendations are: (1) a new flight release equipment code be designated for autothrottle and/or autopilot/coupled VNAV aircraft (either one group code or two separate codes). (2) Mandate that in order to be filed; cleared; or fly these complex arrivals both the autothrottles and autopilot coupled VNAV must be operational. (3)All other aircraft must be cleared via some other form of navigation. Here's a little perspective on the matter. An aircraft without GPS [or DME/DME/IRU] may not fly these arrivals. Why? Because lesser avionics lack the required track accuracy! Question: Is compliant vertical navigation less important than Lateral navigation? I certainly don't think so. Here's a little more perspective. If the controller were to individually issue each altitude and speed restriction on these arrivals as we approach them; each aircraft would need a dedicated controller; since the controller wouldn't have time to do anything except issue new clearances; that's how frequent the restrictions come. Should flight crews be required to be that busy? That we have to check; crosscheck; and crosscheck again multiple times all the way down the arrival? There is just too much complexity and too much potential for error. Until this problem is fixed; in the future I will have to see what my options are; but my current plan is to advise the controller that I am unable to accept a clearance to 'descend via' on these complex arrivals. If ATC asks why; I'll simply advise that our aircraft are not equipped for such complex arrivals; and I don't feel I can assure that I can comply with all of the required restrictions as a result. I wish I knew of a better option for me; but I don't. Every time we fly one of these arrivals we are setting ourselves up for a potential violation at nearly every fix; because one deviation increases the potential for another on the next. If we misjudge one; we may not make the next one. Finally; I don't understand the reason for the complexity of these arrivals. If each restriction is truly necessary there must be a real safety concern involved. If there isn't a real need--and busting an altitude or speed isn't a major safety issue--then why on earth do they make them so complex? If the complexity is really necessary; either issue these arrivals to aircraft equipped to fly them and keep the rest of us off of them or; at the very least; do not require that we 'descend via' when on these arrivals. Something needs to be done before something tragic happens.
A CRJ900 Captain expressed serious concerns about the ability of his aircraft to comply with the complex and numerous altitude/airspeed restrictions on OPD RNAV STARs such as the BOOSH at STL. He asked valid questions as to why there are distinct requirements for lateral navigation accuracy (GPS or DME/DME/IRU) but no equivalent requirements for airborne autoflight/VNAV systems which would enable equally precise vertical navigation.