Narrative:

At 8800 ft MSL and climbing at 1400 FPM, phx TRACON told us to level at 9000 ft for 9500 ft VFR traffic. As PNF, I set 9000 ft in the altitude window on the master control panel, (the first officer was flying with autoplt #2 engaged, we were previously cleared to 15000 ft) and selected open descent. The A320 does not respond quickly -- it's flight control laws will protect a pitch up or pitch over to maintain no more than a 1 'G' maneuver. The first officer pushed the stick forward as we were passing 9100 ft. The autoplt disconnected but altitude still rose to 9600 ft. The first officer and the FAA inspector in the jumpseat saw the traffic just before I did and the first officer turned right to avoid the traffic, a single-engine aircraft. We passed by around 1/2 mi away at the same altitude before we could descend to 9000 ft. The problem was a very late call by ATC combined with the fact that our TCASII did not give a timely warning. At air carrier X the TCASII alert has very narrow parameters to display traffic and, in this case, the parameters did not come into play until we were within 500 ft of the traffic and climbing. It would be better if we had the ability to show traffic 1000-2000 ft above or below us. Also, the A320 flight control laws slow the ability to make a quick change via autoplt and our training emphasizes smooth control inputs. A possibly quicker input to the stick may have kept our altitude lower. The TCASII resolution commands were correct and we made the proper inputs but the conflict would have been quite close without the turn.

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Original NASA ASRS Text

Title: ALTDEV. LATE CALL FROM ATC FOR LEVEL OFF. ACFT PROTECTION MODES DISCOURAGE EXTREME MANEUVERS.

Narrative: AT 8800 FT MSL AND CLBING AT 1400 FPM, PHX TRACON TOLD US TO LEVEL AT 9000 FT FOR 9500 FT VFR TFC. AS PNF, I SET 9000 FT IN THE ALT WINDOW ON THE MASTER CTL PANEL, (THE FO WAS FLYING WITH AUTOPLT #2 ENGAGED, WE WERE PREVIOUSLY CLRED TO 15000 FT) AND SELECTED OPEN DSCNT. THE A320 DOES NOT RESPOND QUICKLY -- IT'S FLT CTL LAWS WILL PROTECT A PITCH UP OR PITCH OVER TO MAINTAIN NO MORE THAN A 1 'G' MANEUVER. THE FO PUSHED THE STICK FORWARD AS WE WERE PASSING 9100 FT. THE AUTOPLT DISCONNECTED BUT ALT STILL ROSE TO 9600 FT. THE FO AND THE FAA INSPECTOR IN THE JUMPSEAT SAW THE TFC JUST BEFORE I DID AND THE FO TURNED R TO AVOID THE TFC, A SINGLE-ENG ACFT. WE PASSED BY AROUND 1/2 MI AWAY AT THE SAME ALT BEFORE WE COULD DSND TO 9000 FT. THE PROB WAS A VERY LATE CALL BY ATC COMBINED WITH THE FACT THAT OUR TCASII DID NOT GIVE A TIMELY WARNING. AT ACR X THE TCASII ALERT HAS VERY NARROW PARAMETERS TO DISPLAY TFC AND, IN THIS CASE, THE PARAMETERS DID NOT COME INTO PLAY UNTIL WE WERE WITHIN 500 FT OF THE TFC AND CLBING. IT WOULD BE BETTER IF WE HAD THE ABILITY TO SHOW TFC 1000-2000 FT ABOVE OR BELOW US. ALSO, THE A320 FLT CTL LAWS SLOW THE ABILITY TO MAKE A QUICK CHANGE VIA AUTOPLT AND OUR TRAINING EMPHASIZES SMOOTH CTL INPUTS. A POSSIBLY QUICKER INPUT TO THE STICK MAY HAVE KEPT OUR ALT LOWER. THE TCASII RESOLUTION COMMANDS WERE CORRECT AND WE MADE THE PROPER INPUTS BUT THE CONFLICT WOULD HAVE BEEN QUITE CLOSE WITHOUT THE TURN.

Data retrieved from NASA's ASRS site as of July 2007 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.