Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
ATC Issue All Types; Conflict NMAC; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action
Weather; Human Factors; Procedure
Heavy thunderstorms in the area; and ATC was having difficulty getting traffic into MEM. Only two arrival gates were open; so we experienced multiple arrival revisions and vectors. At the time of the incident there were multiple aircraft in close proximity and the controller was very busy. What happened was very dangerous; a near mid-air; so my recollection of the sequence of events may not be exactly correct. After the flight the three of us discussed the events to clarify what happened.After multiple vectors we were finally cleared direct to ROCAB for the HOBRK 1 arrival. We were at FL220. My first officer asked the controller if we were cleared to descend; since we were high. Location was between HOBRK and ROCAB. Clearance was 'descend via the HOBRK 1'. We said we'd have trouble making the 10;000 ft. restriction at ROCAB and the controller said do the best you can. As we started down we got a TCAS 'Traffic; Traffic' alert; and the display showed an aircraft directly in front of us 100 Ft. above. I did not note the exact distance but I think it was within 5 nm. Immediately thereafter came the TCAS RA; 'descend; descend now.' I referenced the display and started an aggressive descent. A few seconds later we got 'climb; climb; increase rate to climb'; with the corresponding display on the PFD. I complied and then got a level off command. We leveled off back at FL220; and told the controller we had the RA. Right after or during the RA; we were given a heading of 360; and I complied. The controller then said we were supposed to be at FL220. The first officer said no; we had been cleared to descend via the arrival; to 10;000 ft. All three of us clearly remember the descent clearance. Then we were cleared direct HOBRK; and the FO said that was behind us; so the controller cleared us back to ROCAB and descent to 7;000; and we complied. We were then vectored to final for RWY 36L and flew the visual/ILS approach and landed.
[Report narrative contained no additional information.]
Air carrier flight crew reported a close encounter with another heavy aircraft while on descent to MEM. Evasive action was taken.