Narrative:

I was flying the aircraft descending on the arrival. We were instructed by ATC to cross 10 NM west from gqe at 10000 ft. We had an expectation of landing on runway 36L because we were coming from the west and ATIS called approachs to runway 36L and runway 36C. Our arrival entry spot into memphis was also on the west side of the field. I had already loaded runway 36L into the FMS and we were descending in profile automation through approximately 12000 ft MSL when our runway was switched to runway 36R. As we leveled at 290 KTS and 10000 ft; we rebriefed the new approach. A few moments later we were given a descent (9000 ft) and a change back to runway 36L. As my first officer began to acknowledge the transmission; I erroneously pulled the descend knob on the flight control panel instead of the heading select knob and began descending before slowing to 250 KTS. Upon realizing my error; I disconnected the autoplt and corrected back to 10000 ft until I slowed to 250 KTS and resumed descent. I went to approximately 9780 ft before correcting. ATC never mentioned or commented on the deviation as I surmise; it was just momentary. The causal factor was the crew; namely me; becoming distraction by the changes in the approach clrncs and allowing the deviation to occur. I was PF but also engaged in pilot monitoring duties by directing first officer on how to make quick FMS changes. In the future I will endeavor to maintain my roles and responsibilities and be more alert for the multiple changes in the approach environment while ensuring the PF maintains situational awareness and pilot monitoring does collateral duties.

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Original NASA ASRS Text

Title: A300 FLT CREW RECEIVES TWO RWY CHANGES ABOVE 10000 FEET DURING APPROACH AND PF INADVERTENTLY DESCENDS BELOW 10000 FEET BEFORE SLOWING TO 250 KTS.

Narrative: I WAS FLYING THE ACFT DSNDING ON THE ARR. WE WERE INSTRUCTED BY ATC TO CROSS 10 NM W FROM GQE AT 10000 FT. WE HAD AN EXPECTATION OF LNDG ON RWY 36L BECAUSE WE WERE COMING FROM THE W AND ATIS CALLED APCHS TO RWY 36L AND RWY 36C. OUR ARR ENTRY SPOT INTO MEMPHIS WAS ALSO ON THE W SIDE OF THE FIELD. I HAD ALREADY LOADED RWY 36L INTO THE FMS AND WE WERE DSNDING IN PROFILE AUTOMATION THROUGH APPROX 12000 FT MSL WHEN OUR RWY WAS SWITCHED TO RWY 36R. AS WE LEVELED AT 290 KTS AND 10000 FT; WE REBRIEFED THE NEW APCH. A FEW MOMENTS LATER WE WERE GIVEN A DSCNT (9000 FT) AND A CHANGE BACK TO RWY 36L. AS MY FO BEGAN TO ACKNOWLEDGE THE XMISSION; I ERRONEOUSLY PULLED THE DSND KNOB ON THE FLT CTL PANEL INSTEAD OF THE HDG SELECT KNOB AND BEGAN DSNDING BEFORE SLOWING TO 250 KTS. UPON REALIZING MY ERROR; I DISCONNECTED THE AUTOPLT AND CORRECTED BACK TO 10000 FT UNTIL I SLOWED TO 250 KTS AND RESUMED DSCNT. I WENT TO APPROX 9780 FT BEFORE CORRECTING. ATC NEVER MENTIONED OR COMMENTED ON THE DEV AS I SURMISE; IT WAS JUST MOMENTARY. THE CAUSAL FACTOR WAS THE CREW; NAMELY ME; BECOMING DISTR BY THE CHANGES IN THE APCH CLRNCS AND ALLOWING THE DEV TO OCCUR. I WAS PF BUT ALSO ENGAGED IN PLT MONITORING DUTIES BY DIRECTING FO ON HOW TO MAKE QUICK FMS CHANGES. IN THE FUTURE I WILL ENDEAVOR TO MAINTAIN MY ROLES AND RESPONSIBILITIES AND BE MORE ALERT FOR THE MULTIPLE CHANGES IN THE APCH ENVIRONMENT WHILE ENSURING THE PF MAINTAINS SITUATIONAL AWARENESS AND PLT MONITORING DOES COLLATERAL DUTIES.

Data retrieved from NASA's ASRS site as of January 2009 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.