Narrative:

Diverted to fll, ory, mia due to WX. I was off ATC, first officer flying. I was speaking to dispatch, when I returned to ATC 5000 ft was set. Aircraft was descending through 8000 ft. At 6000 ft I called 6000 ft for 5000 ft. At 5500 ft ATC said to maintain 6000 ft, please. We climbed back to 6000 ft and I told ATC we were cleared to 5000 ft. They said we were not. Flight continued without further problems and landed in fll.

Google
 

Original NASA ASRS Text

Title: A DSNDING B767-300 OVERSHOT ITS ASSIGNED ALT OF 6000 FT. CAPT HAD BEEN ON COMPANY CALL WITH DISPATCH FOR A DIVERSION OP.

Narrative: DIVERTED TO FLL, ORY, MIA DUE TO WX. I WAS OFF ATC, FO FLYING. I WAS SPEAKING TO DISPATCH, WHEN I RETURNED TO ATC 5000 FT WAS SET. ACFT WAS DSNDING THROUGH 8000 FT. AT 6000 FT I CALLED 6000 FT FOR 5000 FT. AT 5500 FT ATC SAID TO MAINTAIN 6000 FT, PLEASE. WE CLBED BACK TO 6000 FT AND I TOLD ATC WE WERE CLRED TO 5000 FT. THEY SAID WE WERE NOT. FLT CONTINUED WITHOUT FURTHER PROBS AND LANDED IN FLL.

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.