Date: 201812
Local time of day: 1201-1800
Location: MSP.Airport, MN
Flight conditions: IMC
Weather elements / visibility: Icing
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
ATC / advisory: TRACON M98
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation - Speed All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert
Contributing factors: Human Factors; Procedure; Airspace Structure
Primary problem: Human Factors

Narrative: Aircraft X was nearing the end of the KKILR3 Arrival into MSP; 12L transition; being vectored on a left downwind for Runway 12L. Several headings from ATC were given and complied with. A descent to 4000 feet was given with a slow to 210 knots or faster when reaching 4000 feet. At 4000 feet; we slowed to 210 knots. During this time; four different aircraft ahead of us were told they had exited the bravo airspace when being changed to the Tower frequency. This was noticed by us and extra care was taken to not do the same. While being given the final vector to join the localizer course and being cleared for the ILS 12L; we were told to cross WASHY (FAF) at 3000 feet. To the best of my knowledge; 3000 feet was set and 4000 feet was maintained until passing abeam HAMML to avoid leaving bravo airspace. When being told by MSP Approach to contact the Tower; we were told that we; 'still exited the bravo airspace for a second but were back in now.' Tower was contacted and the rest of the flight was accomplished without incident. I am not aware of the controller's motivations here; but this does appear to be a bit of a set up. When being vectored onto an approach in IMC and icing conditions; a flight crew does have a few things on their mind. Being assigned a speed of 210 knots is suspiciously 10 knots faster than is allowed below bravo airspace. Four aircraft in a row were given the same descent to the final approach fix being told to hold 210 knots. All were told they exited the bravo. ATC appeared to take no action to avoid this confusion with any subsequent aircraft. Despite recognizing this and taking our own precautions; we were told the same. If the Approach Controller assigned a 200 knot speed; this would be a non-issue. If a slightly steeper intercept was given with instructions of maintain 4000 until HAMML; cleared for the ILS 12L; again; this would be a non-issue. If a descent to 3000 feet is given outside of HAMML; a crew is likely to descend to get down to 3000 feet to avoid being above the glideslope at a high workload time period. It's not a shock that so many crews did this. Some other items of note: Being more than 10 degrees off the localizer means glideslope indications are not reliable to the flight crew. The approach plate for 12L shows two rings at 5nm and 10nm showing the MSA altitudes; not the class B altitudes/floors. The Class B airspace chart is horrible to read and understand in real time; but shows the floors of the Class B. Also; the distances on this chart are measured from MSP VOR. The distance being monitored on the approach and the distances on the approach chart are from the IPJL localizer. This is also a time when a crew is managing icing conditions in IMC; communicating with ATC; configuring the aircraft; running checklists; etc. In the future; when being given vectors and step downs in bravo airspace at MSP; I will advise the Approach Controller than I am unable to maintain faster than 200 knots.




Synopsis: Air carrier pilot reported ATC did not provide adequate guidance to remain within Bravo airspace.