MD-80 Series (DC-9-80) Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Workload; Human-Machine Interface; Distraction
Aircraft Equipment Problem Critical; Deviation - Altitude Crossing Restriction Not Met
Flight Crew FLC Overrode Automation; Flight Crew Returned To Clearance
Procedure; Human Factors; Aircraft
We were assigned the TRUP RNAV STAR into DCA in our MD80. We initiated the profile descent using GPS VDI in VS mode; however; the VDI guidance had us high on the first hard crossing altitude so I reverted to manual (human brain) vertical guidance to complete the arrival. My observation and concern for safety is that this type of procedure requires a total heads down operation and the pilot flying is almost completely removed from traffic watch; systems monitering etc. If anything were to happen during the intense VNAV operation of trying to make all the stupid crossing and speed restrictions; chances are great the anomalies would go unobserved.I suggest we have the guys who design procedures get in the lowest common denominator aircraft; test fly the procedure and evaluate the safety ramifications prior to publishing. The designers must ask ordinary users on both sides of the radar screen if changes are reasonable; necessary and safe.
After abandoning autoflight due to its inability to comply with the altitude constraints on the TRUPS RNAV STAR to DCA an MD-80 Captain expressed his belief the STAR (and other RNAV STARS of similar complexity) are incompatible with rudimentary RNAV systems such as those installed on his aircraft.