ASRS 2053244

Reporter 1

During RNAV arrival to [Runway] 31R ATC apparently cleared us to IAF SUMLN, but we thought we heard the alternate IAF of JALIM which was closer to our position. We read back and proceeded to JALIM. Neither we nor ATC caught the read back error, partially due to very congested communications on that frequency. After a couple of minutes ATC queried us asking us if we were proceeding to SUMLN. We responded negatively and that we thought we heard the similar sounding JALIM. ATC then immediately cleared us to JALIM and cleared us for the RNAV to 31R. We do not believe separation from other aircraft was lost. The rest of the approach went eventually. Solution: One of the two IAF waypoints needs to be renamed to a dissimilar sounding waypoint as the other IAF.

Reporter 2

Upon arrival via RNAV RNP 31R, ATC apparently cleared us to SUMLN IF and we read back JALIM. ATC inquired if we proceeding to SUMLIN and we again read back JALIM, which ATC then cleared us to start the approach from. The similar sounding fixes in a radio traffic saturated area led us to proceeding to the incorrect fix assigned by ATC. The approach, landing and taxi to the gate was uneventful. Solution: Change one of the IF names to something that is not similar in sound to the other.