Date: 201507
Local time of day: 1801-2400
Location: ATL.Airport, GA
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B ATL
ATC / advisory: TRACON A80
Second aircraft: Airbus Industrie Undifferentiated or Other Model
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Situational Awareness
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Landing Without Clearance; Inflight Event / Encounter Wake Vortex Encounter
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented
Contributing factors: Environment - Non Weather Related; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: While on the arrival into Atlanta; approach control cleared us direct to GRMPI intersection with a speed of 210 KTS. They then gave us a clearance direct to DEPOT intersection join the localizer slow to 180 KTS. They advised us we were following an Airbus and asked if we had the field or the traffic. We had the field in sight so we called it. ATC then gave us the instructions slow to 170 KTS. Follow the Airbus Cleared for the visual approach contact tower at DEPOT 119.3. Before we would have switched they gave us a final instruction to slow to 160 KTS. This last clearance occurred just prior to joining the ILS. This required us to make some additional configuration changes to get the plane slowed (we configured out of sequence by putting the gear down before we went flaps 30 to silence the horn). As soon as we hit DEPOT the plane rocked as we felt wake turbulence from the Airbus ahead. The captain opted to turn off the autopilot and hand fly the remainder of the approach and stated he wanted to stay a little high to avoid the Airbus's wake. I checked TCAS and noted that we were approximately 2-2.5 miles in trail of the Airbus. Quickly after we encountered the wake turbulence; as things smoothed out; we got the stick shaker briefly which lasted for a second or less. The captain and I were confused as to why that occurred. Our speed was over ref by about 3 KTS and had no indication of windshear; nor were any rapid control inputs made. We discussed this briefly and since we were above 1000 FT we decided to continue. This event caused me to become extra vigilant and focused on monitoring the gauges especially the airspeed and low speed cues and for windshear indications. We never received any other indications of low speed or the shaker for the remainder of the approach. Just prior to touchdown; ATC called us and advised us to contact tower. I looked down and had the tower frequency in the 'PRE' select side of the RTU (Radio Tuning Unit). I switched over immediately and gave our call sign to the tower. The tower responded back with our call sign and nothing else. We touched down immediately following that exchange and continued with a normal roll out. As we exited the runway the tower controller advised us to hold short of 27R at N5 and monitor tower 123.85. We continued to taxi to the gate without any further incidents other than noting the 27R controller gave a windshear alert for his runway. After parking the captain and I discussed what had happened and came to the conclusion that during the multiple ATC instructions; aircraft configuration changes; and wake turbulence all at DEPOT; immediately followed by the stick shaker; we became task saturated followed by fixating on the threat of what caused the shaker to go off along with the wake turbulence and possible windshear; we lost sight of the task of contacting the tower. The threats we identified during this sequence of events were; the multiple ATC instruction changes while joining the localizer at the outer marker; the quick configuration changes to keep the aircraft on speed; the wake turbulence we encountered following the Airbus; the inadvertent stick shaker; the weather; and loss of the big picture by focusing on the one problem (the shaker). An additional threat occurred when approach contacted us right before touchdown to call the tower. This caused additional confusion and panic as we scrambled to contact them while realizing our mistake. The obvious error we made was not contacting the tower for landing clearance. We were able to mitigate some the other threats by staying ahead of the airplane and adjusting as necessary. This has been a learning experience; and we were able to take out of it to be more vigilant with radio communication and possibly set up personal reminder that we have in fact been cleared to land (turning on the landing light). Going around was another option we discussed and we did choose to continue since we were about 5 miles out and hadplenty of speed and altitude when the shaker activated; nor did we know what caused the shaker to come on for that brief moment.




Synopsis: CRJ-200 First Officer reported they had to be reminded to call Tower on short final into ATL; after being distracted by a wake turbulence encounter.