Narrative:

The flight was a scheduled flight from atl to ccs. It was my first time into ccs, the first officer had been there several times before. On letdown, we were switched from maiquetia control to caracas approach. A descent clearance was given to 7000 ft. I became concerned we were getting in too close for a descent to the airport. The radios were quiet, and I glanced at the radio and realized we were on the wrong frequency. I am not sure how it happened. I flipped the frequency selector to approach and they gave us an immediate vector to avoid traffic and intercept the localizer, and a descent clearance. The only traffic observed and on TCASII was ahead to the right about 2500 ft below us. From this point we completed a normal approach and landing. For the life of me I don't know how this happened, how we got on the wrong frequency. The radio is a dual frequency selector and it's possible it was accidentally knocked from approach back to maiquetia control. After thinking about this a few days, another possibility occurred to me. During the descent, a flight attendant knocked on the door to enter and asked if we were sterile. I said no, we were above 10000 ft. Apparently he just wanted to look out the window. I don't remember if the first officer engaged him in conversation or not. This may have contributed to the whole scenario. I may have set in the approach frequency then either became distraction with the flight attendant and forgot to call, or called on the wrong frequency and flipped the selector back to maiquetia after unlocking the door. It seems whenever you are interrupted in the middle of a sequence, it is very easy to miss even the most obvious steps. This would have been an incredible error on my part, but the more I think about it, the more I feel this is what happened. Managing or eliminating distraction is important. At air carrier is seems the flight attendants always come forward at the end of the flight, usually at the top of descent. Usually it is just chit-chat, but it is nonetheless a distraction. This is at a time when their workload is decreasing, but ours is increasing as we enter a critical phase of flight. One way to eliminate this would be to extend the sterile cockpit rule to cruise level -- in other words, pushback to leveloff and descent to block-in. Climbs and dscnts are readily identifiable in the cabin and would be easily recognized by the crews. This would have to be mandated by the FAA. If it wasn't and any captain tried to implement this on his own, it would be misinterped as being cold and unfriendly and this would lead to other problems in crew coordination. This would have other benefits as well. In the area of altitude deviation, at air carrier almost all of ours occur in the mid-levels above 10000 ft and FL330. The safety department attributes the lack of busts below 10000 ft, in part, to the sterile cockpit rule. I completely agree, and feel it is in everybody's best interest to extend the sterile cockpit to cruise level. If nothing else, it could be implemented on a trial basis, with both objective data obtained and subjective crew input gathered as to its benefits, down sides, and ultimate value.

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Original NASA ASRS Text

Title: FLC OF A B757 MISSES FREQ CHANGE OF DSCNT TO CCS.

Narrative: THE FLT WAS A SCHEDULED FLT FROM ATL TO CCS. IT WAS MY FIRST TIME INTO CCS, THE FO HAD BEEN THERE SEVERAL TIMES BEFORE. ON LETDOWN, WE WERE SWITCHED FROM MAIQUETIA CTL TO CARACAS APCH. A DSCNT CLRNC WAS GIVEN TO 7000 FT. I BECAME CONCERNED WE WERE GETTING IN TOO CLOSE FOR A DSCNT TO THE ARPT. THE RADIOS WERE QUIET, AND I GLANCED AT THE RADIO AND REALIZED WE WERE ON THE WRONG FREQ. I AM NOT SURE HOW IT HAPPENED. I FLIPPED THE FREQ SELECTOR TO APCH AND THEY GAVE US AN IMMEDIATE VECTOR TO AVOID TFC AND INTERCEPT THE LOC, AND A DSCNT CLRNC. THE ONLY TFC OBSERVED AND ON TCASII WAS AHEAD TO THE R ABOUT 2500 FT BELOW US. FROM THIS POINT WE COMPLETED A NORMAL APCH AND LNDG. FOR THE LIFE OF ME I DON'T KNOW HOW THIS HAPPENED, HOW WE GOT ON THE WRONG FREQ. THE RADIO IS A DUAL FREQ SELECTOR AND IT'S POSSIBLE IT WAS ACCIDENTALLY KNOCKED FROM APCH BACK TO MAIQUETIA CTL. AFTER THINKING ABOUT THIS A FEW DAYS, ANOTHER POSSIBILITY OCCURRED TO ME. DURING THE DSCNT, A FLT ATTENDANT KNOCKED ON THE DOOR TO ENTER AND ASKED IF WE WERE STERILE. I SAID NO, WE WERE ABOVE 10000 FT. APPARENTLY HE JUST WANTED TO LOOK OUT THE WINDOW. I DON'T REMEMBER IF THE FO ENGAGED HIM IN CONVERSATION OR NOT. THIS MAY HAVE CONTRIBUTED TO THE WHOLE SCENARIO. I MAY HAVE SET IN THE APCH FREQ THEN EITHER BECAME DISTR WITH THE FLT ATTENDANT AND FORGOT TO CALL, OR CALLED ON THE WRONG FREQ AND FLIPPED THE SELECTOR BACK TO MAIQUETIA AFTER UNLOCKING THE DOOR. IT SEEMS WHENEVER YOU ARE INTERRUPTED IN THE MIDDLE OF A SEQUENCE, IT IS VERY EASY TO MISS EVEN THE MOST OBVIOUS STEPS. THIS WOULD HAVE BEEN AN INCREDIBLE ERROR ON MY PART, BUT THE MORE I THINK ABOUT IT, THE MORE I FEEL THIS IS WHAT HAPPENED. MANAGING OR ELIMINATING DISTR IS IMPORTANT. AT ACR IS SEEMS THE FLT ATTENDANTS ALWAYS COME FORWARD AT THE END OF THE FLT, USUALLY AT THE TOP OF DSCNT. USUALLY IT IS JUST CHIT-CHAT, BUT IT IS NONETHELESS A DISTR. THIS IS AT A TIME WHEN THEIR WORKLOAD IS DECREASING, BUT OURS IS INCREASING AS WE ENTER A CRITICAL PHASE OF FLT. ONE WAY TO ELIMINATE THIS WOULD BE TO EXTEND THE STERILE COCKPIT RULE TO CRUISE LEVEL -- IN OTHER WORDS, PUSHBACK TO LEVELOFF AND DSCNT TO BLOCK-IN. CLBS AND DSCNTS ARE READILY IDENTIFIABLE IN THE CABIN AND WOULD BE EASILY RECOGNIZED BY THE CREWS. THIS WOULD HAVE TO BE MANDATED BY THE FAA. IF IT WASN'T AND ANY CAPT TRIED TO IMPLEMENT THIS ON HIS OWN, IT WOULD BE MISINTERPED AS BEING COLD AND UNFRIENDLY AND THIS WOULD LEAD TO OTHER PROBS IN CREW COORD. THIS WOULD HAVE OTHER BENEFITS AS WELL. IN THE AREA OF ALTDEV, AT ACR ALMOST ALL OF OURS OCCUR IN THE MID-LEVELS ABOVE 10000 FT AND FL330. THE SAFETY DEPT ATTRIBUTES THE LACK OF BUSTS BELOW 10000 FT, IN PART, TO THE STERILE COCKPIT RULE. I COMPLETELY AGREE, AND FEEL IT IS IN EVERYBODY'S BEST INTEREST TO EXTEND THE STERILE COCKPIT TO CRUISE LEVEL. IF NOTHING ELSE, IT COULD BE IMPLEMENTED ON A TRIAL BASIS, WITH BOTH OBJECTIVE DATA OBTAINED AND SUBJECTIVE CREW INPUT GATHERED AS TO ITS BENEFITS, DOWN SIDES, AND ULTIMATE VALUE.

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.