After abandoning autoflight due to its inability to comply with the altitude constraints on the trup...

Narrative:

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.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1043544
Time
Date	201210
Local Time Of Day	1801-2400
Place
Locale Reference	DCA.Airport
State Reference	DC
Aircraft 1
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR TRUPS1
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Altitude Crossing Restriction Not Met

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.