B737-700
Flight Crew Last 90 Days 265
Communication Breakdown
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Procedure
Approaching DIRTY on the arrival into ATL several things occurred simultaneously that increased pilot workload. In addition; two fixes with similar names caused confusion that resulted in the flight initially flying to the wrong fix. First; we were assigned a runway different than planned and given an altitude/airspeed assignment that differed from the arrival. We were high and told to keep speed up. I notified the Flight Attendant to secure the cabin for arrival. Shortly thereafter; ATC cleared us direct to BAMBU (a fix on ILS 26R). As ATC was transmitting the flight attendants were making their cabin announcement. The First Officer (pilot not flying) didn't respond to ATC (he had PA volume up). I was monitoring the PA and thought I heard ATC clear us to BAMMM; which is on the arrival. Since the First Officer didn't respond I thought he had radio problems so I replied to ATC and started toward BAMMM. I didn't detect the difference in the two fixes. Shortly thereafter; ATC asked if we were direct to BAMBU and gave us a heading to BAMBU and the descent. I asked ATC if there was a problem and they said no. The First Officer is from another carrier and flew a different type of aircraft previously and has been on the line five months. They are too difficult to distinguish during a typically busy time. Second; unless absolutely sure; ask ATC to confirm that what you heard is fact.
B737 Captain reports confusion during a busy arrival; believing that a clearance direct BAMBU on ILS 26R is instead a clearance to BAMMM on the DIRTY 2 arrival. A track deviation is quickly corrected by ATC.