Narrative:

Filed route: mia agw BR53L rajay BR55V cobbl BR3L gtk A555 ddp sju. On a flight from mia-sju and receiving various radar vectors from ZMA, we were issued a heading to intercept A555 southeast of gtk then flight plan route, which was read back by the first officer as 'heading 130 to intercept A555 flight plan route.' if ZMA issued a different arrival route for sju we did not acknowledge it through our readback. After being handed off to ZSU we were instructed 'cleared to FL290 cross coqui intersection at 11000 ft, pilot's discretion.' after discussing the clearance with the first officer we determined the clearance was pilot's discretion to FL290 then cross coqui at 11000 ft. Reviewing the arrival routing based on our last assigned clearance from ZMA, coqui intersection was not on our routing. I informed ZSU our last clearance was A555 to ddp then sju. Coqui intersection is on airway route 6. Using terminology such as 'flight plan route' when an airway uses a name like 'route 6' could have resulted in the misinterp. ZSU issued a heading to intercept route 6. A short time later ZSU informed us that we were to descend to FL290 then cross coqui at 11000 ft, that descent to FL290 was not at pilot's discretion, but the descent to cross coqui was. I informed ZSU that we understood the clearance to be pilot's discretion to FL290 then cross coqui at 11000 ft. We received a 20 degree heading change and complied with center's instructions. When a clearance is issued, which contains nonstandard terminology or format, it should be questioned until its intended meaning is understood. We receive descent clrncs with crossing restr very regularly from ZID, but in a different format than issued by ZSU which led to misinterp. Supplemental information from acn 274034: when a clearance is issued which contains nonstandard terminology or format, it should be questioned until completely understood. Often there is an implied pressure on the crew to get the clearance right the first time and there is a reluctance to take the time to question/clarify the controller's clearance. We regularly receive a variety of descent clrncs with crossing restrs from ZID and they are all very clear because they use standard terminology, phraseology and format, and seem to be different than the one issued by ZSU which resulted in this confusion and misinterp.

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Original NASA ASRS Text

Title: ATC ENRTE CLRNC NOT UNDERSTOOD.

Narrative: FILED RTE: MIA AGW BR53L RAJAY BR55V COBBL BR3L GTK A555 DDP SJU. ON A FLT FROM MIA-SJU AND RECEIVING VARIOUS RADAR VECTORS FROM ZMA, WE WERE ISSUED A HDG TO INTERCEPT A555 SE OF GTK THEN FLT PLAN RTE, WHICH WAS READ BACK BY THE FO AS 'HDG 130 TO INTERCEPT A555 FLT PLAN RTE.' IF ZMA ISSUED A DIFFERENT ARR RTE FOR SJU WE DID NOT ACKNOWLEDGE IT THROUGH OUR READBACK. AFTER BEING HANDED OFF TO ZSU WE WERE INSTRUCTED 'CLRED TO FL290 CROSS COQUI INTXN AT 11000 FT, PLT'S DISCRETION.' AFTER DISCUSSING THE CLRNC WITH THE FO WE DETERMINED THE CLRNC WAS PLT'S DISCRETION TO FL290 THEN CROSS COQUI AT 11000 FT. REVIEWING THE ARR ROUTING BASED ON OUR LAST ASSIGNED CLRNC FROM ZMA, COQUI INTXN WAS NOT ON OUR ROUTING. I INFORMED ZSU OUR LAST CLRNC WAS A555 TO DDP THEN SJU. COQUI INTXN IS ON AIRWAY RTE 6. USING TERMINOLOGY SUCH AS 'FLT PLAN RTE' WHEN AN AIRWAY USES A NAME LIKE 'RTE 6' COULD HAVE RESULTED IN THE MISINTERP. ZSU ISSUED A HDG TO INTERCEPT RTE 6. A SHORT TIME LATER ZSU INFORMED US THAT WE WERE TO DSND TO FL290 THEN CROSS COQUI AT 11000 FT, THAT DSCNT TO FL290 WAS NOT AT PLT'S DISCRETION, BUT THE DSCNT TO CROSS COQUI WAS. I INFORMED ZSU THAT WE UNDERSTOOD THE CLRNC TO BE PLT'S DISCRETION TO FL290 THEN CROSS COQUI AT 11000 FT. WE RECEIVED A 20 DEG HDG CHANGE AND COMPLIED WITH CTR'S INSTRUCTIONS. WHEN A CLRNC IS ISSUED, WHICH CONTAINS NONSTANDARD TERMINOLOGY OR FORMAT, IT SHOULD BE QUESTIONED UNTIL ITS INTENDED MEANING IS UNDERSTOOD. WE RECEIVE DSCNT CLRNCS WITH XING RESTR VERY REGULARLY FROM ZID, BUT IN A DIFFERENT FORMAT THAN ISSUED BY ZSU WHICH LED TO MISINTERP. SUPPLEMENTAL INFO FROM ACN 274034: WHEN A CLRNC IS ISSUED WHICH CONTAINS NONSTANDARD TERMINOLOGY OR FORMAT, IT SHOULD BE QUESTIONED UNTIL COMPLETELY UNDERSTOOD. OFTEN THERE IS AN IMPLIED PRESSURE ON THE CREW TO GET THE CLRNC RIGHT THE FIRST TIME AND THERE IS A RELUCTANCE TO TAKE THE TIME TO QUESTION/CLARIFY THE CTLR'S CLRNC. WE REGULARLY RECEIVE A VARIETY OF DSCNT CLRNCS WITH XING RESTRS FROM ZID AND THEY ARE ALL VERY CLR BECAUSE THEY USE STANDARD TERMINOLOGY, PHRASEOLOGY AND FORMAT, AND SEEM TO BE DIFFERENT THAN THE ONE ISSUED BY ZSU WHICH RESULTED IN THIS CONFUSION AND MISINTERP.

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.