Flight Crew Air Transport Pilot (ATP)
Distraction; Communication Breakdown; Confusion; Workload
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Inflight Event / Encounter Other / Unknown
Air Traffic Control Issued Advisory / Alert; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Clearance; Flight Crew FLC complied w / Automation / Advisory
Human Factors; Procedure; Environment - Non Weather Related
After hand-off from Center to Approach; I heard the tail-end of an event warning from Approach control regarding our preferred runway - 34R. At check in with Approach I asked what the event at approach end 300 MSL was; and the controller did not answer me; instead giving instructions - assignment to a different runway than expected (34L); and a heading of 010 to intercept the localizer. I read the clearance back; then I queried controller two more times about the issue with 34R before controller responded to me - the event was unauthorized drone activity on the approach path. Shortly thereafter I was looking at the CDI and thinking the vector to join was not very good. Then Approach called and asked if we were off of the arrival. I responded that we were flying the assigned heading to join the localizer; and controller said that our clearance was present heading to join. At that point controller gave us heading 020 to join; which was a more effective vector. The approach to landing proceeded normally from that point; although the position of the drone reports changed somewhat. There were no terrain or traffic separation issues.The sudden report of the drone seems to have thrown everyone's game off just a bit. I only heard a fragment of the report; and in good weather conditions I was wondering what the warning could be about. The sudden change also changed the workload for the controller. I am pretty sure I heard 010 heading; I don't know if it was a controller error or hear back/read back error. I did make a mistake by combining my query with the check in call - I should have made that two separate communications. Or I also could have waited to hear the report again; as we were more than 20 miles from the airport and there was really no time pressure (other than getting our preferred runway to end the day).If my read back was in error; the controller did not correct me from 'heading 010' to 'present heading'.
Approach cleared us for the RNAV Arrival and we were told to expect Runway 34L. After passing QWENN intersection and within 20 miles of the airport; Approach instructed us to 'fly present heading (about heading 010) and intercept the localizer for Runway 34L.' We read back the instructions correctly and complied as instructed. Right after they gave the instructions; they also made a general announcement to all aircrafts within the airspace regarding an unauthorized drone activity at about 300 - 400 AGL between Runways 34L and 34R. The captain queried Approach at least twice for more information regarding the drone; but Approach failed to respond due to multiple aircrafts receiving instructions for arrival. While this was all happening; the same Approach Controller then queried us within a few minutes; after receiving our said instruction; on why we departed from the assigned arrival course. We reiterated to the same controller that they instructed us to 'fly present heading to intercept the 34L localizer.' We then asked a confirmation question to which controller responded 'nope.' We were then instructed to fly a heading of 020 to properly join the 34L localizer. The rest of the approach to landing was uneventful. The root cause was lack of communication. It was a busy time since Approach Control was handling multiple aircraft at once and at the same time they were dealing with an unauthorized drone activity in the vicinity of the final approach course. ATC should have said something to the contrary when we read back the instructions given to us to fly a heading to join a localizer.
A UAV presence at 300 feet on the final approach to SLC parallel runway overloaded the TRACON and disrupted communications with arriving flight crews. All associated personnel experienced workload increases.