A319
Confusion; Communication Breakdown
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance
Procedure; Human Factors
Approaching ORD; runway and arrival plan changing continuously. Throughout arrival and approach; instructed to change speed repeatedly (slow/fast/slow/fast). Eventually told to join the LOC for [Runway] 27L. About 40 miles out and 10;000 feet and 250 KTS; cleared to cross GRABL at 7;000 feet and cleared for the ILS 27L approach. Told to maintain 210 KTS; which was complied with. A few minutes later; we were instructed to be at 170 KTS at TAFFS and contact Tower at TAFFS. I did not switch to Tower immediately; but did within a few minutes and prior to TAFFS. Approach continued; established on GS and at 210 KTS; Captain started slowing down in order to reach 170 KTS by TAFFS. Gear Down/Configuration 1 and spoilers extended. Approximately 6-7 mile final; Tower called and instructed us to go-around and up to 4;000 feet. Go-around executed on autopilot initially; than hand flown by Captain. Right traffic and switched to Departure who vectored us for a visual to 27R. During downwind; Controller informed us we needed to call the Tower after we landed. Remainder of flight uneventful. Captain's call to the Tower revealed two issues: first; a misunderstanding of the speed restriction at TAFFS; both crew members believed we should be at 170 KTS by TAFFS; not slow to 170 KTS immediately and maintain until TAFFS. Since the last few speed assignments were to speed us up; this was logical. Second; we switched to Tower frequency too quickly (but did not contact per ATC instructions) and Approach was not able to get a hold of us in a timely manner when they became aware of our excessive speed. I have only been to ORD a half dozen times; but remember switching to Tower immediately on previous visits; including on IOE. In fact; our publications state 'it is imperative that you change immediately [to Tower] and monitor that frequency for RADAR advisories.' However; Approach Controller claims that we were supposed to stay with them but this was not clear from communications. The Captain was informed that a loss of separation had occurred. No cockpit indications (TA or RA) were received and proximity to aircraft ahead never crossed my mind during the approach. The 'hand off' to Tower occurs at least 20 miles and 5 minutes before they actually want you to switch frequencies! If you want me to stay on your frequency; don't tell me to switch to Tower when I'm 20 miles out if you really want me to switch to Tower when I'm on a 5 mile final. Why give me the instruction to switch if you really want me to stay? ORD is one of very few airports that I have seen this happen and in my opinion is a setup for this kind of situation to happen. Different controllers have different expectations. Operations department needs to have a discussion with ORD ATC and see what their expectations are in this regard. Our company pages should be updated to remove or correct possibly misleading information in Arrivals section.
Air carrier arrival to ORD voiced concern regarding the ATC handling reference speed assignments and transfer of communication instructions.