Narrative:

I was the pilot monitoring on a flight to lga. We were inbound on the korry 3 arrival and began to receive numerous clrncs to change the arrival in one way or another. After passing eno we were given the ATC clearance to 'descend via the korry arrival and to also cross skipy at or below FL220.' the first officer initially selected flight level change to expedite our descent to get below FL220 while he inputted this change to the arrival; and after we descended below FL220 he went back to VNAV. We complied with all of these clrncs. A short time after this we were given anther clearance to cross brand at 250 KTS. My first officer made the necessary input to the FMS. The ATC controller informed us he would have holding instructions in a moment. Sometime around the time of issuing holding instructions at rbv to us; he also restated the clearance to descend via the korry arrival; however; to now cross brand at 11000 ft. The printed arrival has brand listed at 11000 ft or above. I remember checking to see that my first officer had correctly changed the FMS to reflect that we now needed to cross brand at 250 KTS and at 11000 ft. The FMS reflected this and I remember that our altitude select window on the MCP reflected 10000 ft as that was the final altitude on the arrival. I had monitored the crossing of all of the previous fixes and was busy checking the arrival page to verify that we had also correctly entered the holding information at rbv when we received a clearance to climb to 11000 ft as there was an aircraft holding at 10000 ft. We were just passing 10600 ft and my first officer immediately selected vertical speed and rolled in a climb of 1500 FPM. I queried the controller to verify that we were cleared to 'descend via the korry arrival;' and he responded that we were but we were to cross brand at 11000 ft. Since I was busy xchking the holding information on the arrival plate; brand was the one fix that I did not actually verify the passing of as we were doing it. The seemingly continual changes that were given to us for the korry arrival caused a significant amount of confusion; into what is already a very busy STAR. If the controller's real intent was for us to never descend below 11000 ft; then that clearance was never received or acknowledged by us. If he wanted us to cross brand at 11000 ft and then descend to 10000 ft; I have to believe that we complied with that as I had previously seen that clearance loaded into the legs page of the FMS. However; I cannot be 100% sure as I did not visually confirm the passing of that particular fix as I was checking the arrival plate to see that the holding instructions were also correctly in the FMS. I think it would help to either have the clearance to descend via or to be given regular ATC clrncs to descend. Using a combination of the two along with holding instructions is potentially creating a situation for miscom or confusion; and most definitely adding a great deal to the pilot's workload.

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Original NASA ASRS Text

Title: A B757 CREW ON THE LGA KORRY 3 STAR DSNDED BELOW THEIR CLRED ALT WHEN TASK SATURATED WITH HOLDING INSTRUCTIONS AND DSCNT CLRNC.

Narrative: I WAS THE PLT MONITORING ON A FLT TO LGA. WE WERE INBOUND ON THE KORRY 3 ARR AND BEGAN TO RECEIVE NUMEROUS CLRNCS TO CHANGE THE ARR IN ONE WAY OR ANOTHER. AFTER PASSING ENO WE WERE GIVEN THE ATC CLRNC TO 'DSND VIA THE KORRY ARR AND TO ALSO CROSS SKIPY AT OR BELOW FL220.' THE FO INITIALLY SELECTED FLT LEVEL CHANGE TO EXPEDITE OUR DSCNT TO GET BELOW FL220 WHILE HE INPUTTED THIS CHANGE TO THE ARR; AND AFTER WE DSNDED BELOW FL220 HE WENT BACK TO VNAV. WE COMPLIED WITH ALL OF THESE CLRNCS. A SHORT TIME AFTER THIS WE WERE GIVEN ANTHER CLRNC TO CROSS BRAND AT 250 KTS. MY FO MADE THE NECESSARY INPUT TO THE FMS. THE ATC CTLR INFORMED US HE WOULD HAVE HOLDING INSTRUCTIONS IN A MOMENT. SOMETIME AROUND THE TIME OF ISSUING HOLDING INSTRUCTIONS AT RBV TO US; HE ALSO RESTATED THE CLRNC TO DSND VIA THE KORRY ARR; HOWEVER; TO NOW CROSS BRAND AT 11000 FT. THE PRINTED ARR HAS BRAND LISTED AT 11000 FT OR ABOVE. I REMEMBER CHKING TO SEE THAT MY FO HAD CORRECTLY CHANGED THE FMS TO REFLECT THAT WE NOW NEEDED TO CROSS BRAND AT 250 KTS AND AT 11000 FT. THE FMS REFLECTED THIS AND I REMEMBER THAT OUR ALT SELECT WINDOW ON THE MCP REFLECTED 10000 FT AS THAT WAS THE FINAL ALT ON THE ARR. I HAD MONITORED THE XING OF ALL OF THE PREVIOUS FIXES AND WAS BUSY CHKING THE ARR PAGE TO VERIFY THAT WE HAD ALSO CORRECTLY ENTERED THE HOLDING INFO AT RBV WHEN WE RECEIVED A CLRNC TO CLB TO 11000 FT AS THERE WAS AN ACFT HOLDING AT 10000 FT. WE WERE JUST PASSING 10600 FT AND MY FO IMMEDIATELY SELECTED VERT SPD AND ROLLED IN A CLB OF 1500 FPM. I QUERIED THE CTLR TO VERIFY THAT WE WERE CLRED TO 'DSND VIA THE KORRY ARR;' AND HE RESPONDED THAT WE WERE BUT WE WERE TO CROSS BRAND AT 11000 FT. SINCE I WAS BUSY XCHKING THE HOLDING INFO ON THE ARR PLATE; BRAND WAS THE ONE FIX THAT I DID NOT ACTUALLY VERIFY THE PASSING OF AS WE WERE DOING IT. THE SEEMINGLY CONTINUAL CHANGES THAT WERE GIVEN TO US FOR THE KORRY ARR CAUSED A SIGNIFICANT AMOUNT OF CONFUSION; INTO WHAT IS ALREADY A VERY BUSY STAR. IF THE CTLR'S REAL INTENT WAS FOR US TO NEVER DSND BELOW 11000 FT; THEN THAT CLRNC WAS NEVER RECEIVED OR ACKNOWLEDGED BY US. IF HE WANTED US TO CROSS BRAND AT 11000 FT AND THEN DSND TO 10000 FT; I HAVE TO BELIEVE THAT WE COMPLIED WITH THAT AS I HAD PREVIOUSLY SEEN THAT CLRNC LOADED INTO THE LEGS PAGE OF THE FMS. HOWEVER; I CANNOT BE 100% SURE AS I DID NOT VISUALLY CONFIRM THE PASSING OF THAT PARTICULAR FIX AS I WAS CHKING THE ARR PLATE TO SEE THAT THE HOLDING INSTRUCTIONS WERE ALSO CORRECTLY IN THE FMS. I THINK IT WOULD HELP TO EITHER HAVE THE CLRNC TO DSND VIA OR TO BE GIVEN REGULAR ATC CLRNCS TO DSND. USING A COMBINATION OF THE TWO ALONG WITH HOLDING INSTRUCTIONS IS POTENTIALLY CREATING A SITUATION FOR MISCOM OR CONFUSION; AND MOST DEFINITELY ADDING A GREAT DEAL TO THE PLT'S WORKLOAD.

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.