Narrative:

Redeye arrival to lax runway 6R. ATC cleared us to 'descend via.' we had leveled off for an extended segment at 10;000 ft as charted; when ATC cleared us 'after smo descend to 4;000 ft.' both of us interpreted this to supersede other altitude restrictions on the arrival and ILS 6R; including smo at 8;000 ft; and waker at 5;100 ft. Accordingly; we crossed smo at 10;000 ft; set 4;000 ft in the altitude window and began descent. Shortly thereafter we were cleared for a visual approach to 6R. All concluded with no complaints from ATC. However; I am now wondering. 1) should we have crossed smo at 10;000 ft - altitude at the time of revised clearance -- or 8;000 ft as published? Did the revised clearance supersede the previous 'descend via?' 2) should we have stopped descent at 5;100 ft until passing waker then descended to 4;000 ft? The circumstances render these questions somewhat academic; since we were just dropping in on a visual approach with no conflicting traffic. A simple addition to the clearance by ATC would have helped; i.e. 'Cross smo at 10;000 ft; then descend to 4;000 ft' or 'cross smo at 8;000 ft; then descend to 4;000 ft.'

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Original NASA ASRS Text

Title: Air Carrier arrival into LAX posses a number of questions regarding ATC's clearance during an approach to Runway 6R.

Narrative: Redeye arrival to LAX Runway 6R. ATC cleared us to 'descend via.' We had leveled off for an extended segment at 10;000 FT as charted; when ATC cleared us 'after SMO descend to 4;000 FT.' Both of us interpreted this to supersede other altitude restrictions on the arrival and ILS 6R; including SMO at 8;000 FT; and WAKER at 5;100 FT. Accordingly; we crossed SMO at 10;000 FT; set 4;000 FT in the ALT window and began descent. Shortly thereafter we were cleared for a visual approach to 6R. All concluded with no complaints from ATC. However; I am now wondering. 1) Should we have crossed SMO at 10;000 FT - altitude at the time of revised clearance -- or 8;000 FT as published? Did the revised clearance supersede the previous 'descend via?' 2) Should we have stopped descent at 5;100 FT until passing WAKER then descended to 4;000 FT? The circumstances render these questions somewhat academic; since we were just dropping in on a visual approach with no conflicting traffic. A simple addition to the clearance by ATC would have helped; i.e. 'cross SMO at 10;000 FT; then descend to 4;000 FT' or 'cross SMO at 8;000 FT; then descend to 4;000 FT.'

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.