A321
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Human-Machine Interface; Time Pressure; Workload
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; Aircraft; Procedure
Washington Center cleared us to cross MAYOS at FL220. While descending in manage descent and on profile; Washington Center instructed us to slow to 250 knots for spacing into CLT. This would put us high on the profile and would cause us to not make the crossing restriction at MAYOS. I applied speed brakes; but this was not enough to increase our rate of descent. We were given a frequency change to Atlanta Center. After the First Officer checked in; I asked him to tell Atlanta Center that we would not be able to cross MAYOS at FL220 because of the 250 knots restriction. Atlanta Center responded 'disregard the speed restriction and cross MAYOS at FL220'. In an attempt to comply with Atlanta Center I selected open descent and increased the speed to 320 knots. At approximately FL250 and about 10 miles to MAYOS the FMGC showed that I was now on profile. I selected the manage descent mode. The aircraft slowly began to decrease both speed and rate of descent. The FMGC continued to show the aircraft was on profile to cross MAYOS at FL220 and 280 knots. It was apparent that the aircraft was not going to make the crossing restriction; I reselected open descent and increased the speed to increase the rate of descent. We crossed MAYOS at 23;700 feet on our way to FL220 and 280 knots.  There was no response from Atlanta Center on the missed altitude restriction at MAYOS.  The event occurred because:1) The controller did not understand that reducing our speed affected our descent rate and therefore our ability to make a given crossing restriction.2) The Pilot Flying was not assertive enough with the controller. He should have stated that they were not able to comply with the crossing restriction regardless of speed.3) The Pilot Flying should have stayed in open descent and probably would have made the crossing restriction.    For the Pilot Flying to be more assertive with a controller when he/she makes complying with a restriction very difficult. As in reducing speed and still expecting to make a crossing restriction. To stay in open descent instead of believing what the FMGC profile is telling you when you do not have a lot of room for error.
An A321 flight crew flying the IVANE RNAV STAR to CLT was cleared to cross MAYOS at FL220 and; then; to reduce IAS to 250 knots.  After doing so it became obvious they couldn't cross MAYOS at FL220 even with speedbrakes extended.  ATC then removed the airspeed and the rate of descent was increased until the FMGC indicated the crossing would be met.  Upon selecting managed descent; the FMGC made no attempt to manage the FL220 crossing at MAYOS and it was crossed at FL237.  ATC made no comment about the failure to comply.