B737-800
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew FLC Overrode Automation; Flight Crew Requested ATC Assistance / Clarification
Aircraft; Human Factors; Procedure
Flight planned via the HAWKZ2 arrival. At FL350; weight 139.2 at T/D; Wind 277/70; DESC FORECAST winds loaded; local altimeter loaded; Cost Index 45 and Descent speed .78/280 per the flight plan. Shortly after beginning descent with Autothrottles armed speed slowed 20 KTS. Thrust levers manually advanced to 50% N1 to stay on speed while descending on path. 45-50% N1 was required until HAWKZ intersection to stay on speed. Quartering headwind had decreased to 24 KTS at FL240 and below. Vertical rate of descent was 1;900 fpm the entire descent. ATIS stated ILS 34L in use which was loaded in FMC prior to T/D. Between HAWKZ and LIINE we were assigned the ILS 34C with the SONDR transition. ILS 34C with SONDR transition entered into FMC. Immediately Vertical bearing showed we were 1;200 FT high and commanded speed dropped to 250 from 270 KIAS. Approaching FOOTT we requested direct to the mall for the visual approach stating we did not want to continue the arrival. Our request was granted. Our workload was significantly increased dealing with trying to get back on path regain the correct airspeed etc. This arrival is neither fuel efficient nor does it reduce our workload. It increases the workload. The new RNAV arrivals into SEA have multiple waypoints with crossing restrictions and speed constraints. These arrivals create task saturation and lack of situational awareness for both pilots monitoring the path and speed on the arrival. ATC changes to the arrival create further complications as the path and speed are affected. These new RNAV arrivals are a safety risk.
B737-800 Captain experiences difficulties complying with the new HAWKZ2 arrival to SEA.