EMB ERJ 135 ER/LR
Flight Crew Air Transport Pilot (ATP)
Workload; Time Pressure; Situational Awareness; Human-Machine Interface; Confusion; Distraction
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew FLC Overrode Automation
Weather; Chart Or Publication; Procedure; Human Factors
For our descent into BOS; we were initially filed on the GARDNER 4 arrival. At some point during our descent; ATC asked if we could accept the QUABN 3 RNAV arrival. As pilot monitoring; I replied 'stand-by' to ATC so that the pilot flying and I could review the QUABN 3 RNAV arrival before accepting it. We mutually determined that we could accept the change in the arrival and notified ATC. We were then cleared present position direct to the UROWT intersection on the QUABN 3 RNAV arrival. At some point while direct UROWT; we were told to expect to cross UROWT at 11;000; however; we did not actually receive clearance to cross UROWT at 11;000 feet until we were already within 15-18 nautical miles from the fix. I do not recall what specific altitude we were at when we received the clearance down to 11;000 feet; but we were above FL200 with a substantial tailwind. We tried in good faith to meet the crossing restriction; but was unable. We notified ATC that we would not meet the crossing restriction about 3 nautical miles prior to UROWT. It is worth mentioning in this report; that while flying this arrival; we were given 3 different runway assignments (Runway 33L; 27; and 32). Considering that the QUABN 3 RNAV arrival is runway specific; our workload was exponentially increased due to trying to comply with altitude restrictions and making sure we were on the proper lateral courses for the assigned runway. We could have notified ATC of our inability to meet the crossing restriction earlier in the descent. ATC should not assign too many runway changes during runway specific arrivals.
Level at FL240 at maybe 30 nm from UROWT and given descend and maintain FL200; expect UROWT at 11;000 feet. We had a 75 knot tailwind and I already had doubts about making the clearance and commented to the First Officer (FO) to that effect. I started down at about 2500 fpm and then the controller gave us 300 knots or less. Again we didn't say unable. Then passing through FL210 and starting to level off about 23 nm from UROWT we were given descend and maintain 17;000 feet expect UROWT at 11;000 feet. I said 'we can't make that' to the FO; but I don't believe he said the words 'unable' to ATC....then when we were trying to tell the controller we were unable to make the crossing she was already telling us to fly the Runway 27 transition and to reduce to 270 KIAS. This further complicated things because the ATIS was advertising 33L. So the FO was verifying that she said Runway 27 and re-programming the FMS to Runway 27. About 14;000 feet we were finally able to tell the controller unable on the crossing. We crossed UROWT 1;100 feet high and 28 knots fast with a tailwind of 68 knots. To further complicate the situation; before the crossing was resolved we were handed off to approach who then assigned us Runway 32 (a 5;000-foot Runway that hadn't been set or briefed and the numbers hadn't been checked and at an airport that I had flown a few times). We refused this immediately and emphatically told them unable. We had been set up and briefed for 33L since we were 150 nm out and then at a critical phase of flight 2 different controllers had tried to change our runway twice in 3 minutes interfering with our ability to tell the controller that she waited too long to give us our descent clearance and that she was unrealistic about her expectations about our performance.  It should have been apparent to all parties involved that it wasn't going to happen and I should have insisted that the FO use the words 'unable' much earlier instead of allowing less assertive words to be good enough.
An EMB-135 flight crew initially cleared by the GARDNER STAR but switched to descend on the QUABN RNAV STAR to BOS with a substantial tailwind--was unable to comply with an ATC directed crossing altitudes at UROWT. Multiple runway changes combined with imprecise altitude expectations created a flight crew workload environment that forced them to reply 'unable' to the last runway change.