A320 FLT CREW EXECUTES AN LDA DME RWY 19 APCH TO DCA USING THE CDAP (CONSTANT DSCNT APCH PROCS) WITH ONLY 1 CREW MEMBER QUALIFIED FOR THE PROC.

Narrative

FIRST LEG OF THE FLT AND THE CREW HAD NOT PREVIOUSLY FLOWN TOGETHER. EACH CREW MEMBER HAS ABOUT 18 MONTHS EXPERIENCE IN LINE OPS ON THE AIRBUS. MIXED CREW: CAPT CDAP QUALIFIED; FO NOT. BRIEFED ILS RWY 1 DCA. JUST PRIOR TO BASE TURN FOR THE ILS; APCH CTL ANNOUNCED LDA DME RWY 19 NOW IN USE. WX HAD JUST BECOME 1000 FT/3 MI (ALTHOUGH THERE WERE SEVERAL LAYERS OF SCATTERED SCUD BEING RPTED BELOW THE CEILING) AND THERE WAS A VARYING 6-9 KT TAILWIND COMPONENT ON RWY 1 CAUSING THE ACFT FROM OTHER COMPANIES TO REQUEST RWY 19 OR NEED TO DIVERT. WE WERE TURNED AROUND FOR VECTOR FOR THE LDA. THE LDA RWY 19 IS NOT LINE SELECTABLE. CAPT AND FO WERE NOW RUSHED. WE ENTERED AS MUCH DATA AS WE COULD IN THE FMGC; BRIEFED THE APCH AND I BRIEFED THE FO ON HIS DUTIES AS PNF ON A CDAP APCH. FO WAS UNFAMILIAR WITH THE TRK-FPA FLT DIRECTOR MODE AND INDICATIONS. WE WERE IMMEDIATELY CLRED FOR THE APCH ONLY 4 MI FROM THE FAF. AFTER MEETING THE INITIAL STEP-DOWN FIX WE DSNDED TO THE 'FA' AND SELECTED TRK-FPA. AT THE FLY-OFF DISTANCE (PUBLISHED) I CALLED FOR 'FPA' 3 DEGS DOWN. THE FO WAS TASK SATURATED WITH OTHER DUTIES AND DID NOT RESPOND. I SELECTED 3 DEGS AND PULLED BUT 'FPA MODE' DID NOT ENGAGE. AT THE SAME TIME I BECAME VISUAL WITH THE RWY AND CONTINUED THE APCH. BY THE TIME I REALIZED THE 'FPA MODE' HAD NOT ENGAGED WE WERE HIGH ON THE CDAP GS. I SELECTED 4 DEGS DOWN; DESELECTED AUTOPLT AND ATTEMPTED TO MAINTAIN 1000 FPM DSCNT RATE. AT ABOUT 500 FT WE RECEIVED A SINGLE 'DSCNT RATE' VERBAL ANNUNCIATION. I IMMEDIATELY CORRECTED BACK TO 1000 FPM AND CONTINUED THE APCH. TOUCHDOWN WAS APPROX 1500 FT DOWN THE RWY AND FIRM BUT NOT HARD. ROLLOUT WAS NORMAL. IN RETROSPECT; I SHOULD HAVE GONE AROUND. I WAS RELUCTANT TO DO SO BECAUSE OF THE VARIABLE WX AND WINDS AND AFTER THE LOW-ALT MANEUVERING; I WAS BECOMING CONCERNED ABOUT FUEL FOR THE ALTERNATE OF PITTSBURG. I ALSO BELIEVED THAT I COULD ACHIEVE A STABILIZED APCH. THERE ARE 2 OUTSIDE FACTORS WHICH CONTRIBUTED TO THIS INCIDENT. FIRST IS THE REQUIREMENT TO FLY A CDAP APCH WITH AN UNTRAINED CREW MEMBER. THIS LEFT ME WITHOUT THE 2-MAN CONCEPT SUPPORT WHICH ACR X PLTS ARE ACCUSTOMED TO AND IS EMPHASIZED IN EVERY OTHER ASPECT OF ACR X FLT OPS. I BELIEVE WE WOULD HAVE BEEN SAFER TO FLY THIS APCH USING THE OLD 'DIVE AND DRIVE' METHOD WHICH BOTH CREW MEMBERS ARE FULLY TRAINED TO FLY. MIXED CREWS SHOULD REVERT TO THE FULLY TRAINED 'DIVE AND DRIVE' RATHER THAN HAVING 1 PERSON TRY TO FLY A PROC WHICH IS TOTALLY UNFAMILIAR TO THE OTHER CREW MEMBER. (I BELIEVE ACR X DID JUST THAT WHEN WE WERE BEING TRAINED ON PRM APCHS.) SECOND; THE LDA RWY 19 SHOULD BE LINE SELECTABLE. IT IS A PRIMARY APCH TO AN ARPT THAT ACR X 319/320'S ROUTINELY USE. I HAVE HEARD OTHER ACR X AIRBUS PLTS EXPRESS CONFUSION REGARDING THE PROPER PROCS TO USE WHEN ASSIGNED THIS APCH. PLEASE DON'T HESITATE TO CALL ME IF I CAN PROVIDE ANY OTHER INFO REGARDING THIS INCIDENT. MY COPLT AND I EXTENSIVELY DEBRIEFED THE APCH. WE HAVE BOTH FILED FSAP RPTS.