Narrative:

We departed kztc (treasure key bahamas) en route to mco VFR. Climbing through 7000 to 12500 we received our IFR clearance to mco. RNAV direct vrb climb to FL200. (ZMA 134.20). Passing 12000 ft, I told the first officer (PF) I was off radio to talk to the passenger (company requirement out of 10000 ft, sterile cockpit not in effect). As I was doing so, the first officer advised me he was going to request 16000 ft as a final. I said ok. I did the PA with my ATC radio off. When I was done with the PA I tuned up my ATC radio and told the first officer 'I'm back.' he said, 'no changes.' minutes later, ZMA asked us what our altitude was. I replied 17000 ft climbing 20000 (20000 was set in the altitude selector). ZMA said, didn't you request 16000 ft? I gave you 16000 ft. We descended to 16000 ft. The first officer did request 16000, but didn't change the altitude selector or inform me when I said, 'I'm back,' in the change in altitude. We were off airway direct vrb, controller said, 'no conflict, but I thought you wanted 16000 ft.' the first officer failed to communication the change verbally or by indicating it with the altitude selector. I failed by not questioning it when I returned, and I now monitor ATC when I make a PA. As well try to avoid single pilot operations on the radio.

Google
 

Original NASA ASRS Text

Title: ALTDEV ALT OVERSHOT IN NON ADHERENCE TO ATC CLRNC.

Narrative: WE DEPARTED KZTC (TREASURE KEY BAHAMAS) ENRTE TO MCO VFR. CLBING THROUGH 7000 TO 12500 WE RECEIVED OUR IFR CLRNC TO MCO. RNAV DIRECT VRB CLB TO FL200. (ZMA 134.20). PASSING 12000 FT, I TOLD THE FO (PF) I WAS OFF RADIO TO TALK TO THE PAX (COMPANY REQUIREMENT OUT OF 10000 FT, STERILE COCKPIT NOT IN EFFECT). AS I WAS DOING SO, THE FO ADVISED ME HE WAS GOING TO REQUEST 16000 FT AS A FINAL. I SAID OK. I DID THE PA WITH MY ATC RADIO OFF. WHEN I WAS DONE WITH THE PA I TUNED UP MY ATC RADIO AND TOLD THE FO 'I'M BACK.' HE SAID, 'NO CHANGES.' MINUTES LATER, ZMA ASKED US WHAT OUR ALT WAS. I REPLIED 17000 FT CLBING 20000 (20000 WAS SET IN THE ALT SELECTOR). ZMA SAID, DIDN'T YOU REQUEST 16000 FT? I GAVE YOU 16000 FT. WE DSNDED TO 16000 FT. THE FO DID REQUEST 16000, BUT DIDN'T CHANGE THE ALT SELECTOR OR INFORM ME WHEN I SAID, 'I'M BACK,' IN THE CHANGE IN ALT. WE WERE OFF AIRWAY DIRECT VRB, CTLR SAID, 'NO CONFLICT, BUT I THOUGHT YOU WANTED 16000 FT.' THE FO FAILED TO COM THE CHANGE VERBALLY OR BY INDICATING IT WITH THE ALT SELECTOR. I FAILED BY NOT QUESTIONING IT WHEN I RETURNED, AND I NOW MONITOR ATC WHEN I MAKE A PA. AS WELL TRY TO AVOID SINGLE PLT OPS ON THE RADIO.

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.