Date: 201811
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Icing; Turbulence
Aircraft: B777-200
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Initial Approach
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Second aircraft: Commercial Fixed Wing
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Workload; Situational Awareness; Confusion; Communication Breakdown; Time Pressure
Second reporter function: First Officer; Pilot Not Flying
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification; Flight Crew FLC Overrode Automation; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Human Factors; Procedure; Weather
Primary problem: Ambiguous

Narrative: Flight out was 30 min late due to late arriving aircraft. WX and NOTAMS for ZZZ indicated a north landing configuration with instrument approaches to [Runway] XXL and XXR. NOTAMS contained a somewhat obscured note among all the CAT2 and CAT3 non-available approaches indicating that the localizer to [Runway] XXL may not be available [for two hours]. No reason for the possible localizer non-availability was given. Our scheduled ETA into ZZZ was [before that give time frame]; but as previously stated; we expected to arrive later than that time. The flight to ZZZ was smooth and uneventful. Last ATIS nearing top of descent indicated ILS approaches to [Runway] XXL and XXR in use with no indication of any localizer non-availability or FAA flight check aircraft operations affecting any localizers. We planned and briefed the ILS to [Runway] XXL; but failed to plan and brief contingencies (mistake). Descent with ZZZ Center was uneventful with only one minor delay vector off of the STAR. Handoff to ZZZ Approach Control occurred as we turned toward ZZZZZ. Approach gave us an easterly heading with a 'descend to 6000 feet' and an 'expect the ILS to XXL.' This affirmed our approach expectation a 'as briefed.' First Officer (Pilot Monitoring) cleaned up; the FMS with course line to [Runway] XXL. We were given a further descent to 4;000 feet and a southeasterly heading and instructed to slow to 160 kts. At the appropriate point we were given a turn toward 020 degrees and instructed to intercept the Localizer to [Runway] XXL. At this moment in time; this localizer was validly tuned and identified. We were then handed off to Final Controller.  Check-in was difficult due to heavy radio chatter by controller to previous aircraft and with an FAA flight-check aircraft arcing at various distances thru ZZZ TRACON airspace in IMC conditions with a high density inbounds in progress. The presence of this FAA aircraft was a blue threat decrease in the safety situation within the ZZZ TRACON airspace and very bad scheduling judgment. Its presence was not in the NOTAMS nor on the ATIS. The Final Controller finally acknowledged our check-in just outside of ZZZZZ1 (14nm) and cleared us for the ILS to [Runway] XXR. We advised the controller that we were on the localizer to [Runway] XXL. The controller then told us that the localizer to [Runway] XXL was not available (the signal was still tuned and identified) and that we could either take the ILS to [Runway] XXR or have the RNAV to [Runway] XXL. We accepted the RNAV clearance to [Runway] XXL. First Officer proficiently changed the FMS to the RNAV [Runway] XXL and briefed differences. Captain switched Flight Directors OFF then ON; but failed to disconnect the autopilot in conjunction. Our altitude was 3;000 feet; speed 160K; and IMC. The engaged localizer would not and did not release. LNAV was therefore not usable. Attempts to manually deselect the LOC switch were unsuccessful. VNAV was engaged with the autopilot tracking the localizer; but our clearance was for the RNAV only. At this point; a yellow autopilot EICAS alert occurred (A/P still engaged) and the aircraft turned rather abruptly to the right. First Officer (Pilot Monitoring) called the deviation immediately. Captain (Pilot Flying) immediately disconnected the A/P and manually flew the aircraft back to the course line for [Runway] XXL. Captain instructed First Officer to tell Final Control that we could not continue our approach and to vector us to the ILS for [Runway] XXR. First Officer quickly reset the FMS to [Runway] XXR and briefed the differences. Approach and landing to [Runway] XXR was uneventful. Advised by Ground Control after landing to call ZZZ TRACON.  Disconnect in effective comm about the situation with the FAA flight check aircraft and its effect on the localizer for [Runway] XXL. Clearing us to intercept the (Localizer) to [Runway] XXL with a situation in play that would stealthily impair the use of that same localizer by causing perturbations to the accuracy of the localizer while giving indications of a good tuned signal to an aircraft using the localizer. Disconnect within the TRACON between the Approach Control and the Final Control about what type of approaches were usable and available. Scheduling an FAA flight check aircraft to operate within the TRACON airspace and to affect the localizer to [Runway] XXL during IMC conditions with a period of high density inbound traffic!!! (VERY BAD JUDGEMENT)Do not conduct FAA flight checks in the ZZZ TRACON during high arrival rate times; especially when the WX is IMC! If this is not possible; then issue better communications about the possible threat of the FAA aircraft's presence in ZZZ airspace. Communicate better with [Operations Control] through the FAA liaison about this threat. Better communication within the TRACON between Approach Control and Final Control about what the plan is and what is happening within the airspace.


Second narrative: The flight was uneventful until we were with the ZZZ Final Controller. In our preparation for our arrival into ZZZ; the Captain (Pilot Flying) briefed the [RNAV] Arrival Landing North Transition with an ILS to Runway XXL. We had checked the ATIS and ZZZ was showing ILS approach to [Runway] XXL available. On descent with Center; I quickly checked the ATIS for an updated altimeter setting and reported information 'H' to ZZZ Approach. On descent with ZZZ Approach; we were given a descent to 6;000 [feet] and vectors to expect Runway XXL. As we approached Runway XXL we were switched over to the Final Controller and given a heading of south (180) and I could see on the TCAS that we were placed in order for the arriving traffic. Eventually; we were given a descent to 4;000 [feet] and then a vector to the east and then again another vector and told to 'intercept the localizer for Runway XXL'. We had a solid ident for Runway XXL and completed the Approach Checklist. We were then given a further descent to 3;000 [feet] and slow to 160 [knots].There was a lot of talking on the radios at this point between the Final Controller and an aircraft that appeared to be conducting flying maneuvers near the airport. The amount of communication from the aircraft and Approach Control was so bad that I was wondering when we would be cleared for the approach. I recall approaching close to ZZZZZ and we had not yet been cleared for the approach and slowly approaching glide path intercept. I wanted to request clearance but could not get a chance with all of the communication between the Final Controller and the aircraft conducting maneuvers. It was frustrating. I was just about to key the mic when the Approach Controller told us that we (what sounded like) were cleared for the ILSXXR. That confused both myself and the Captain; so I responded that we were on the ILS for [Runway] XXL. This seemed to confuse the Approach Controller. Then; the controller told us that the ILS for Runway XXL was not up and that we needed to accept the RNAV to [Runway] XXR or vectors to the ILS [Runway] XXR. This was confusing as we were getting solid indications that the ILS [Runway] XXL was tune and identified and we were tracking on the localizer. The Captain quickly decided that we would accept the RNAV to [Runway] XXL; and as I was heads down loading the FMS; I noticed an 'autopilot' EICAS pop up. We tried to get the autopilot to accept the RNAV (Engage LNAV/VNAV) but the localizer would not disengage. This led to more confusion and then I noticed that our heading was indicating that we were also no longer tracking down the localizer but now heading northeast. I notified the Captain and he disconnected the autopilot; corrected out flight path; and flew manually. The Captain quickly made the decision to abort the approach and told me to request vectors for the ILS XXR. I remember the controller giving us a command to turn left to 030 [heading]. This was very confusing again as 030 [heading] was to our right 30 degrees. The Approach Controller changed the heading to; I believe 090; and at 3;000 [feet]; we aborted the approach to [Runway] XXL. As we were heading eastbound I noticed that the autopilot EICAS message was no longer visible and the Captain activated the autopilot. I built the ILS for XXR and briefed the Captain of the new changes and then we executed the ILS XXR to a landing. Sometime on this approach we were told to call [a phone number].I am sure I am missing some of the fine details as this all happened very quickly in a very short time. After landing I pulled up the ATIS and printed out 'H'. At that time I noticed that [Runway] XXL went from and ILS to an RNAV. I did not catch this on the descent and I regret not seeing it. We had briefed the ILS XXL and the last time I checked ATIS that is what it showed. We were told to expect [Runway] XXL and we were given vectors to intercept the localizer for [Runway] XXL so that also reinforced that the ILS was still operational. We also had indications the localizer was tuned and identified. Cause1. Confusing NOTAMS- I took this NOTAM to read that CAT II/III instrument approaches were not operational. (No rollout guidance) I did take this to read that CAT I instrument approaches were still available. I overlooked the time impact on this as I was expecting to arrive before [scheduled start time]. When we were delayed 30 minutes; I should have caught this and I did not. 2. Radio Chatter- The radio chatter between the Final Controller and the aircraft conducting maneuvers was excessive and badly timed with the arrival of aircraft. It was difficult to decipher comms and determine what was going on. 3. Cleared for the Localizer- In all of my years flying at [my company]; cleared to intercept the localizer is the call you receive while inbound for an ILS approach. I believe the controller was expecting us to fly the ILS XXL and something happened while we were inbound on the course. Or maybe he thought he was giving us vectors to intercept the localizer XXR. There was definite confusion between us and the controller. Suggestions1. For myself; and us as flight crew; pay closer attention to the NOTAMS and updated ATIS information. 2. For the aircraft conducting maneuvers; consider doing this at some other time. Definitely not during the arrival of many [company] aircraft. Why not conduct these tests at times when [the company] is not conducting major operations and in VMC conditions only. The radio chatter between the aircraft and Approach Control was far too much which led to communications overload for the controller and added more confusion.3. For Approach Control; we should have been told to expect the RNAV XXL on initial check-in. We were never given that instruction and instead given vectors to intercept a localizer. I am sure there was some confusion with the controller giving us vectors for the localizer instead of direct to the initial for the RNAV approach. While on the localizer; the Approach Controller told us to either accept the RNAV or vectors to an ILS for the other runway. This is very high stress in the cockpit in the final approach phase of the flight; not standard procedures and not trained for. There was definite confusion compounded by the FAA aircraft conducting ill-timed instrument checks on an active runway.


Synopsis: B777 flight crew reported confusion in regard to the clearance provided by the Final Controller.