A Captain new to the Airbus was on altitude; but fast passing GRAMM Intersection on the LAX RIVER TWO ARRIVAL. ATC questioned the crew's speed; but allowed them to continue while slowing with Runway 25L traffic in sight.
Synopsis
A Captain new to the Airbus was on altitude; but fast passing GRAMM Intersection on the LAX RIVER TWO ARRIVAL. ATC questioned the crew's speed; but allowed them to continue while slowing with Runway 25L traffic in sight.
Narrative
Just passed GRAMM Intersection at FL190 assigned and 280 KTS. Was cleared to descend via the arrival; assigned 250 KTS; and cleared for the 24R Approach. In order to try to make the 14000 FT restriction on the STAR; I disengaged the autopilot and increased the descent rate; also extending full speed brakes. I wasn't sure at this point if I could make the restriction; but I decided to make the altitude and let the speed increase. I made the restriction; but the added speed had closed the distance on parallel traffic for 25L. SOCAL Approach Controller asked about my speed; and First Officer admitted we had been going faster. Being pretty new to the Airbus; I wasn't sure if we could make the restriction; and wasn't sure how much extra speed would be the result of the increased descent. What I should have done is tell SOCAL as soon as we were assigned 250 KTS that we couldn't make the restriction; thus giving SOCAL the option to change the clearance or vector us away. I had thought of an alternate plan; to slow to 245 KTS (below the landing gear limit speed); lower the landing gear; and try to make the restriction that way; but that still requires a speed deviation; and doesn't guarantee that the altitude restriction can be met anyway.
Second reporter narrative
After we made the altitude constraint and the Captain was slowing back to 250; the Controller inquired about our airspeed; which I told him was 260 slowing back to 250. He said in a scolding tone; you were assigned 250; and I responded that we could not meet the altitude constraint without increasing airspeed. He then asked if we had the RJ traffic on the SEAVU arrival to 25L in sight; to which we replied affirmative. That traffic appeared to be about 5 NM away from us and well below our altitude. Changing his tone; he said maintain visual; he's for 25L you're for 24R and switched us to the next SOCAL Controller for the north runways. He had given us conflicting directives; which we did our best to comply with; but could not; and he said nothing more.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.