Narrative:

Approaching dfw with WX north and west. Briefed runway 18R at top of descent. After checking with approach and looking at radar, requested runway 17L to provide most distance from WX. Approach concurred. At approximately 10000 ft over dfw, approach cleared us to 6000 ft and requested expedite to 'beat WX to the field.' captain suggested gear down, which we did and expedited at 230-240 KTS. Approximately abeam end of runway and prior to leveling, we were cleared to 4000 ft and shortly after to 3000 ft. Captain indicated to approach we had field in sight. Approach cleared us for visual and down to 2000 ft. Captain initiated heading selected to approximately 230 degrees. At this point, we were on a fairly close in downwind and I knew we would have a busy approach. During turn to final, there was some miscom with captain. I planned on intercepting final outside FAF and on localizer. I was dividing my time looking outside and in, as I had the airport in sight. We were still on autoplt and in left turn when captain said to keep it turning and suggested I 'click it off' (apparently meaning autoplt). I disconnected autoplt just prior to and as we were leveling and continuing intercept at approximately 25-30 degree bank. We also needed to slow rapidly for flap extension, so I pulled throttles back (disconnecting autoplt). At this point, I heard 'dual input' and captain indicating to keep it turning. He was concerned about WX to west of final. Unfortunately, between looking outside, quickly leveling, 'dual input' call, captain's comment, and need to slow, I failed to retract speed brake and maintain full situational awareness of speed. Speed slowed below vls. I noticed at same time captain called 'speed' I had added some power, but not enough. As I aggressively added power, captain retracted speed brake and selected flaps 1 degree. We then accelerated to managed speed, intercepted GS and proceeded remainder of approach stable. During flare we encountered some rough air and some float. As I landed in touchdown zone, I again heard 'dual input.' captain had apparently added nose down to ensure we got and kept nose down. I initially thought captain 'dual input' may have been accidental due to captain in ready position and turbulence. It was also clear that he wanted more bank during turn. We extensively debriefed after flight. Looking back, the suggestion by ATC that we expedite for WX initially made me think, should we be rushing to beat WX and did not advocate strongly to question this. When we were on downwind, I thought and mentioned we might widen/extend, but as I mentioned, we were cleared for visual and again, I could have advocated strongly. During turn to final, I let the rapid pace and distrs of WX, ATC and unusual dual input distract me from the task at hand. This resulted in slow airspeed. I also should have recognized that the captain was in a better position for a visual on left side of aircraft and better view of WX and runway. I should have suggested he fly the visual. Lastly, this was the 4TH leg of a very long duty day and I should have recognized my limitations and indicated desire for more leisurely approach. I learned a great deal from this and will carry many tools with me to future flts. Supplemental information from acn 619517: the dual inputs resulted in my attempt to assist without relinquishing control of the aircraft, allowing the first officer latitude to fly the arrival when in retrospect I should have taken control since the airport was on my side.

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Original NASA ASRS Text

Title: A319 FLT SLOWED BELOW VLS DURING VISUAL APCH TO DFW.

Narrative: APCHING DFW WITH WX N AND W. BRIEFED RWY 18R AT TOP OF DSCNT. AFTER CHKING WITH APCH AND LOOKING AT RADAR, REQUESTED RWY 17L TO PROVIDE MOST DISTANCE FROM WX. APCH CONCURRED. AT APPROX 10000 FT OVER DFW, APCH CLRED US TO 6000 FT AND REQUESTED EXPEDITE TO 'BEAT WX TO THE FIELD.' CAPT SUGGESTED GEAR DOWN, WHICH WE DID AND EXPEDITED AT 230-240 KTS. APPROX ABEAM END OF RWY AND PRIOR TO LEVELING, WE WERE CLRED TO 4000 FT AND SHORTLY AFTER TO 3000 FT. CAPT INDICATED TO APCH WE HAD FIELD IN SIGHT. APCH CLRED US FOR VISUAL AND DOWN TO 2000 FT. CAPT INITIATED HDG SELECTED TO APPROX 230 DEGS. AT THIS POINT, WE WERE ON A FAIRLY CLOSE IN DOWNWIND AND I KNEW WE WOULD HAVE A BUSY APCH. DURING TURN TO FINAL, THERE WAS SOME MISCOM WITH CAPT. I PLANNED ON INTERCEPTING FINAL OUTSIDE FAF AND ON LOC. I WAS DIVIDING MY TIME LOOKING OUTSIDE AND IN, AS I HAD THE ARPT IN SIGHT. WE WERE STILL ON AUTOPLT AND IN L TURN WHEN CAPT SAID TO KEEP IT TURNING AND SUGGESTED I 'CLICK IT OFF' (APPARENTLY MEANING AUTOPLT). I DISCONNECTED AUTOPLT JUST PRIOR TO AND AS WE WERE LEVELING AND CONTINUING INTERCEPT AT APPROX 25-30 DEG BANK. WE ALSO NEEDED TO SLOW RAPIDLY FOR FLAP EXTENSION, SO I PULLED THROTTLES BACK (DISCONNECTING AUTOPLT). AT THIS POINT, I HEARD 'DUAL INPUT' AND CAPT INDICATING TO KEEP IT TURNING. HE WAS CONCERNED ABOUT WX TO W OF FINAL. UNFORTUNATELY, BTWN LOOKING OUTSIDE, QUICKLY LEVELING, 'DUAL INPUT' CALL, CAPT'S COMMENT, AND NEED TO SLOW, I FAILED TO RETRACT SPD BRAKE AND MAINTAIN FULL SITUATIONAL AWARENESS OF SPD. SPD SLOWED BELOW VLS. I NOTICED AT SAME TIME CAPT CALLED 'SPD' I HAD ADDED SOME PWR, BUT NOT ENOUGH. AS I AGGRESSIVELY ADDED PWR, CAPT RETRACTED SPD BRAKE AND SELECTED FLAPS 1 DEG. WE THEN ACCELERATED TO MANAGED SPD, INTERCEPTED GS AND PROCEEDED REMAINDER OF APCH STABLE. DURING FLARE WE ENCOUNTERED SOME ROUGH AIR AND SOME FLOAT. AS I LANDED IN TOUCHDOWN ZONE, I AGAIN HEARD 'DUAL INPUT.' CAPT HAD APPARENTLY ADDED NOSE DOWN TO ENSURE WE GOT AND KEPT NOSE DOWN. I INITIALLY THOUGHT CAPT 'DUAL INPUT' MAY HAVE BEEN ACCIDENTAL DUE TO CAPT IN READY POS AND TURB. IT WAS ALSO CLR THAT HE WANTED MORE BANK DURING TURN. WE EXTENSIVELY DEBRIEFED AFTER FLT. LOOKING BACK, THE SUGGESTION BY ATC THAT WE EXPEDITE FOR WX INITIALLY MADE ME THINK, SHOULD WE BE RUSHING TO BEAT WX AND DID NOT ADVOCATE STRONGLY TO QUESTION THIS. WHEN WE WERE ON DOWNWIND, I THOUGHT AND MENTIONED WE MIGHT WIDEN/EXTEND, BUT AS I MENTIONED, WE WERE CLRED FOR VISUAL AND AGAIN, I COULD HAVE ADVOCATED STRONGLY. DURING TURN TO FINAL, I LET THE RAPID PACE AND DISTRS OF WX, ATC AND UNUSUAL DUAL INPUT DISTRACT ME FROM THE TASK AT HAND. THIS RESULTED IN SLOW AIRSPD. I ALSO SHOULD HAVE RECOGNIZED THAT THE CAPT WAS IN A BETTER POS FOR A VISUAL ON L SIDE OF ACFT AND BETTER VIEW OF WX AND RWY. I SHOULD HAVE SUGGESTED HE FLY THE VISUAL. LASTLY, THIS WAS THE 4TH LEG OF A VERY LONG DUTY DAY AND I SHOULD HAVE RECOGNIZED MY LIMITATIONS AND INDICATED DESIRE FOR MORE LEISURELY APCH. I LEARNED A GREAT DEAL FROM THIS AND WILL CARRY MANY TOOLS WITH ME TO FUTURE FLTS. SUPPLEMENTAL INFO FROM ACN 619517: THE DUAL INPUTS RESULTED IN MY ATTEMPT TO ASSIST WITHOUT RELINQUISHING CTL OF THE ACFT, ALLOWING THE FO LATITUDE TO FLY THE ARR WHEN IN RETROSPECT I SHOULD HAVE TAKEN CTL SINCE THE ARPT WAS ON MY SIDE.

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.