Date: 201910
Local time of day: 1801-2400
Location: S46.TRACON, WA
Flight conditions: VMC
Light: Night
Aircraft: EMB ERJ 135 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B SEA
ATC / advisory: TRACON S46
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Confusion; Situational Awareness
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Airspace Structure; Procedure; Human Factors
Primary problem: Human Factors

Narrative: I was Pilot in Command and Pilot Flying. Aircraft was on approach. During the approach; the clearance was to descend to 2;000 ft. and a heading was given. The Pilot Monitoring and I confirmed with ATC to descend to 2;000 ft. 2;000 ft. was selected on the altitude alerter. The Aircraft leveled off at 2;000 ft. and a heading was given for vectors to the ILS approach. ATC after giving us a vector asked if we had the airport in sight. Both my First Officer and I at this time were looking outside to see if we could see the airport. At this time we both could not verify that we had the airport in sight. We continued with our heading and assigned altitude of 2;000 ft. At this time; the aircraft was about to go past the final approach course. We then told ATC that we still do not have the airport in sight. As soon as we contacted ATC; ATC replied by saying that he tried to call us numerous times and immediately gave us another vector and told us to immediately climb to 2;200 ft. At this time; I immediately climbed the aircraft from 2;000 ft. to 2;200 ft. with a new heading. After climbing to 2;200 ft. and flying to the new assigned heading I verified with my First Officer if we missed any radio calls from ATC. We both confirmed that we did not hear ATC trying to get a hold of us after ATC asked if we had the airport in sight. We actually made a call to ATC to alert ATC that we do not have the airport in sight because we were going to go through the final approach course. ATC then gave us a few vectors back for the ILS approach and cleared us for the approach. We proceeded to contact Tower and were cleared to land.After landing; Ground Control contacted us and told us to call Approach indicating that there might be a possible pilot deviation. My First Officer and I were shocked to hear that there might be a possible Pilot deviation. We were unaware of any pilot deviations. We flew the correct altitudes; speeds; and headings all throughout the approach. As soon as engines were shut down and passengers deplaned I proceeded to call Approach on my cell phone. I introduced myself as the Pilot in Command. There was a lady that picked up the phone and told me that the reason for the call was because the aircraft flew below MVA (Minimum Vectoring Altitude) I was shocked! She then asked for my pilot certificate number; cell number; and address. She indicated to me that the ATC read backs have not been checked and played at this time. She indicated that there will be a review of the tapes and it will be up to FSDO to decide whether any actions will be taken. It is to my surprise that I was told to contact Approach due to possible Pilot deviation. Both my First Officer and I are not aware of ANY pilot deviations. Both my First Officer and I were certain that we did not miss any radio calls when on approach. We read back altitude clearances and verified the altitude after setting the altitude on the altitude selector per our SOP. From this day forward; I will ensure to leave 121.50 on Com #2 until we have touched down and when Ground Control is to be contacted. This will ensure that we would receive a call from ATC in the event Com #1 cannot be communicated through for whatever reason.




Synopsis: Air carrier flight crew reported a communication breakdown and possible ATC error that caused them to fly below the MVA while on approach.