B737-800
Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 3750
Deviation - Altitude Crossing Restriction Not Met; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Weather; Aircraft; Procedure
We were filed for the CHPTR2 arrival and just prior to its first point ATC asked if we were able to fly the BNKR2 arrival. We reviewed and discussed the arrival as published; conducted a route check; checked NOTAMS and concluded that we would be able to conduct that arrival. Upon acceptance; we updated the FMC with the BNKR2 and updated the altitude and airspeed constraints as well as the forecast winds for the descent. We made the first point of PONZE a hard altitude to enable geopath descent; and were given a speed of 270 knots by ATC prior to BANKR. At around CONTR prior to OPALS I ascertained that the autopilot VNAV would not be able to meet its restriction at OPALS and elected to utilize speed brakes and idle descent to increase descent rate. The autopilot upon passing OPALS then increased its downward pitch to meet the restriction by BLNCE and increased airspeed to 290 Knots. Shortly afterwards; we received a vector from ATC to aid in slowing to the published airspeed. After slowing below 270 knots I elected to utilize the gear to further increase our drag and descent rate to get on profile for the ILS 36L approach. During the approach the Controller asked us to contact their Supervisor upon landing to discuss this arrival as there were other instances of 737NG's not being able to meet the restrictions. The Captain discussed the scenario on the phone after landing via the number provided. After review of the arrival between the points DEBBT and BLNCE there is a large amount of altitude to lose in relatively short distance that the VNAV descent could not accomplish or calculate correctly. That in conjunction with a large tail wind further complicates the arrival. The VNAV function in the 737NG has difficulty commanding the aircraft for descent while conducting this arrival which is most evident at points CONT to OPALS. Altering CONT or OPALS to hard altitudes may aid the VNAV in calculating proper descent profiles.
Initially we were filed for the CHPTR2 arrival. Approaching IRQ the Controller asked if we could fly the BANKR2. We checked the NAV database in the FMC and the arrival was listed. I checked the company pages and comments and saw no restrictions for this arrival. The First Officer reconfigured the FMC and we completed a new route check to include published altitudes and airspeeds. In addition; the predicted winds were entered on the descent page for VNAV accuracy. We were recleared to PONZE and given a crossing restriction to cross PONZE at 27;000 feet and the VNAV descent switched to a geopath descent after crossing PONZE. The controller assigned a descent speed of 270 knots and the First Officer entered the new airspeed on the descent page. The VNAV profile was on speed and altitude from PONZE until CONTR when it suddenly indicated the aircraft was over 3000 feet high. The First Officer asked for the landing gear to be extended to help with the speed reduction and descent. The Controller noted our altitude just as I was going to ask for relief and gave us a vector to extend our base. We descended to the profile and descended to the assigned altitude. The Controller asked us to call their Supervisor upon landing. I called the Supervisor and he stated multiple 737-800 were having problems with this arrival similar to what we experienced. I noted that there were specific notes on the CHESLY arrival in our company pages; but nothing on the BANKR2. He indicated that it was his understanding there were company notes on this arrival. I checked our pages and flight paperwork and didn't find anything.After reviewing the arrival post landing it doesn't appear that the aircraft can handle the descent profile from CONTR above 11000 feet to the subsequent points and associated altitudes for OPALS and BLANCE. It is worth noting that we had a 90 knot tailwind in the descent making the restrictive crossing restrictions harder to reach. The altitudes on the STAR need to be adjusted to be less demanding during the final segment of the arrival or lower altitudes need to be published further back on the approach to ensure the arrival doesn't require a steep descent and deceleration at the same time
B737-800 flight crew reported the aircraft was unable to meet the published crossing restrictions.