Narrative:

We were descending for arrival at fco (rome, italy). We had been cleared down from FL350 to FL270 and were expecting further descent. As we passed corsica we received and acknowledged a clearance to FL170 which we believed was for us. As we were descending through FL185 the italian controller asked for our altitude. He then stated that we should still be at FL270 and requested us to maintain FL190, which we immediately complied with. We had been in descent for at least 4 mins before ATC noticed our deviation. 2 pilots heard and agreed on the clearance to FL170. To say we were surprised is an understatement. No conflict in traffic was observed on the TCASII during the event. Some italian controllers are particularly hard to understand as was the case here and obviously contributed to the miscom. We often ask for clrncs to be repeated to verify routings etc, in europe. In this case we were expecting a descent and the clearance was heard and agreed upon by 2 pilots as was the call sign air carrier X, but was either given in error or misinterp. We continued to rome without incident. We all know we must listen very carefully in a foreign environment, but sometimes anticipating a clearance calls for even greater vigilance because of the clearance you don't set.

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Original NASA ASRS Text

Title: ACR LEAVES ASSIGNED ALT IN FOREIGN OP WHEN CALL SIGN IS USED IN ERROR OR CLRNC WAS MISUNDERSTOOD.

Narrative: WE WERE DSNDING FOR ARR AT FCO (ROME, ITALY). WE HAD BEEN CLRED DOWN FROM FL350 TO FL270 AND WERE EXPECTING FURTHER DSCNT. AS WE PASSED CORSICA WE RECEIVED AND ACKNOWLEDGED A CLRNC TO FL170 WHICH WE BELIEVED WAS FOR US. AS WE WERE DSNDING THROUGH FL185 THE ITALIAN CTLR ASKED FOR OUR ALT. HE THEN STATED THAT WE SHOULD STILL BE AT FL270 AND REQUESTED US TO MAINTAIN FL190, WHICH WE IMMEDIATELY COMPLIED WITH. WE HAD BEEN IN DSCNT FOR AT LEAST 4 MINS BEFORE ATC NOTICED OUR DEV. 2 PLTS HEARD AND AGREED ON THE CLRNC TO FL170. TO SAY WE WERE SURPRISED IS AN UNDERSTATEMENT. NO CONFLICT IN TFC WAS OBSERVED ON THE TCASII DURING THE EVENT. SOME ITALIAN CTLRS ARE PARTICULARLY HARD TO UNDERSTAND AS WAS THE CASE HERE AND OBVIOUSLY CONTRIBUTED TO THE MISCOM. WE OFTEN ASK FOR CLRNCS TO BE REPEATED TO VERIFY ROUTINGS ETC, IN EUROPE. IN THIS CASE WE WERE EXPECTING A DSCNT AND THE CLRNC WAS HEARD AND AGREED UPON BY 2 PLTS AS WAS THE CALL SIGN ACR X, BUT WAS EITHER GIVEN IN ERROR OR MISINTERP. WE CONTINUED TO ROME WITHOUT INCIDENT. WE ALL KNOW WE MUST LISTEN VERY CAREFULLY IN A FOREIGN ENVIRONMENT, BUT SOMETIMES ANTICIPATING A CLRNC CALLS FOR EVEN GREATER VIGILANCE BECAUSE OF THE CLRNC YOU DON'T SET.

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.