Date: 201812
Local time of day: 1801-2400
Location: ATL.Airport, GA
Flight conditions: IMC
Weather elements / visibility: Thunderstorm; Turbulence
Aircraft: Medium Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B ATL
ATC / advisory: Tower ATL
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Distraction; Situational Awareness
Second reporter function: Pilot Not Flying
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I was on Local position. Aircraft X was flying erratic; going slightly north and south of localizer but within parameters. There was a monitor in place (A80) and the TCP transfer control point was set at 1 mile. There was zero visibility; 6500+ RVR reading. Monitor O at A80 never made a transmission. Once inside a mile; I noticed on [radar display] the aircraft drifting south at altitude of 1400. I told the pilot to go around; he didn't respond initially; I made another go around transmission which the pilot did respond to. Turned the aircraft south; issued wake turbulence [caution] from a departure and handed aircraft off to approach. The ASDE-X AMass did alert with the new system installed to warn of an aircraft lined up for a taxiway. Aircraft X appeared lined up for taxiway R.Other than approach maybe being more on top of the erratic behavior of pilot outside of TCP; everything worked out with the new system installed on ASDE-x good. It saved a potential accident.


Second narrative: I was the FO (First Officer) and pilot monitoring for the flight to ATL. This was my second flight in [this model of aircraft]; being common typed with our [other aircraft model]. My first flight was as pilot flying. On this particular flight in question we were returning to ATL. ATL had been experiencing a series of storms with low visibility (1 SM) and low ceilings (300 feet). ATL was advertising ILS PRM approaches. Our assigned STAR took us between 2 storm cells; nicely avoiding both but we had to enter some weather for the final approach. When we were handed off to ATL approach we were assigned runway 9R for the ILS PRM. This was the last leg of a [multi-]day trip that contained a lot of night flying and a significant amount of low ceilings and ILS approaches during the trip. The CA (Captain); as pilot flying; had generally turned off the autopilot and flight director between 7000 feet and 10;000 feet and hand flown the remainder of the arrival; approach and landing. He did so on every leg and as pilot monitoring I paid additional attention to monitoring the flight path. The CA was a good hand flying pilot and maintained heading or course; altitude and airspeed very well. On this leg he did as he had done all previous legs and turned off the autopilot and flight director after we were given a 360 degree heading to intercept the 9R ILS into ATL at 8000 feet. We were cleared for the ILS PRM approach and intercepted the localizer and then the glideslope. The monitoring controller did a radio check on the monitoring frequency while we were tracking the localizer before intercepting the glideslope. While tracking the localizer I noticed and announced a couple times we had a right quartering tail wind that could push us toward the 8L ILS path. The CA; hand flying; was tracking the localizer well. During the descent on glide slope at about 4000 feet MSL he got about 'of a dot high' at one point. I announced he was getting high at 'a dot' and he corrected back to glideslope while maintaining airspeed and calling for gear down to add drag and assist with the tailwind. As we descended the tailwind was shifting dramatically from a right quartering tailwind at 39 knots to a full tailwind and varying in speed up to 10 knots. During the approach; the CA was making left and right heading corrections to maintain the localizer but the wind shifts; and tailwind were making it more difficult and he was making larger and larger corrections to maintain the localizer. At this point we were sliding left and right on the localizer up to 'dot' but no greater. Somewhere between 3000 feet and 2000 feet MSL but above 1000 feet AGL the CA asked for approach mode; adding automation and the flight director to assist with his approach. I confirmed we were clear to land at 1000 feet AGL and the missed approach altitude was set. The CA was very closely following the flight director commands but the flight director was commanding even larger left and right heading changes; 10 to 15 degrees left and right of the inbound course; to track the localizer. We were still within 1 dot left and right but the flight director was commanding turns that were 'S' turning us across the localizer; back and forth. The flight director commands were becoming larger but it seems the director movement was delayed so we were passing through the localizer with greater and greater distance each time we passed through it. At 300 feet AGL (radio altimeter) I saw the approach lights at about our 10 o'clock to 10:30 position and announced approach lights left. As I came to the realization we could not align with the runway and I was about to call 'Go Around' the CA called 'Go Around' and we initiated the go around procedure (set power; flaps 8; gear up; speed mode; heading mode) and I called the tower to announce we were going around. I was attempting to select white needles; but because [this aircraft] only has one FMS my muscle memory of which direction and how manyclicks to move the source selector was proving challenging. Tower or final monitor then called again telling us to go around. I called back we were going around. At about 1500 feet to 2000 feet MSL the controller gave us a turn to heading 180; caution wake turbulence from a heavy departure but no altitude and queried if we lost the localizer. I confirmed the call heading 180 degrees; turned the heading knob to 180; and called our current altitude climbing to 4000 feet (from the published missed). The controller confirmed 4000 feet for our missed altitude; told us we would be going back for the ILS runway 10; gave us the localizer frequency; and queried on the cause for our missed. I told the controller I'd get back to him in a moment on the cause as I was putting in the localizer frequency and the CA was calling for flaps up. I needed a moment to verify we had everything set. The CA mentioned internally the go around was for an unstable approach. On my next radio call I passed to the controller we went around for an unstable approach. The CA apologized for going around and stated he would use the autopilot for the next approach. I told him no apology necessary; going around was the safe and right thing to do and that varying tailwind was very challenging to reassure him. Reaching 4000 feet he engaged the autopilot. We completed another; successful; ILS PRM approach to runway 10 with the additional automation assistance. During the taxi to the gate we were given a number to call for possible pilot deviation. The CA called the tower and spoke with the controller. It seems when I queued the mic to call go around; the tower was also trying to call us to tell us to go around and the second call for go around that came in was received after we had already initiated the go around. The CA explained the cause for our go around with the controller. Storms at the arrival airport caused variable tailwinds adding additional challenge to the ILS PRM approach. The crew's choice of automation level added complications to a critical phase of flight resulting in a missed approach.The controller during the go around did a good job and provided useful information. Go-arounds are challenging as pilots because we do them infrequently and there is a significant amount to do in a compressed time frame. It would have been more helpful if the controller; after we established we were going around and he wanted us to execute an alternate missed approach; if he had given us the heading and altitude to climb to and stopped at that information. He gave us the heading but I assumed the missed approach altitude from the published missed approach. He also queried about the reason for the go around during a critical initial phase of the missed approach. I needed a moment to prioritize brain power to flying and navigating before I could reflect on the recent past to effectively judge what was wrong. It would have been better if he asked that question about 30 seconds later not with the initial alternate missed approach information.


Synopsis: Local Controller and pilot not flying reported an unstable approach led to a go around.