Narrative:

Altitude deviation. I was obtaining oceanic clearance on headset and the first officer was monitoring ATC and flying on headset when he started a climb from FL330 to FL350. After writing down the clearance and turning back on the #1 radio, london asked if we were climbing. I said yes and asked what altitude they wanted. London advised that we had climbed without clearance and to maintain FL350. The first officer had monitored the oceanic clearance and when shannon gave the time and altitude for 5710N of not before XA42Z and to cross at FL350, he thought that london had told us to cross. I was not monitoring ATC and did not know that he climbed without clearance until the climb was complete. I have flown with the first officer on several occasions and he always does a fine job. Shannon sounded like london and he simply made an error. It did not dawn on him that I was answering shannon and not london until london control called us. Supplemental information from acn 451910: at FL330 captain was getting oceanic clearance from shanwick while I was monitoring center. When oceanic clearance was coming I turned up the volume on that frequency to the clearance. After the 57n010w not before XA42Z and at FL350. I did not realize that the clearance was not given by london control and thought we were cleared to FL350 anytime before reaching 010W. While climbing to FL350 the controller asked about the climb and we replied that we were cleared to FL350. The controller said we were not, but let us maintain FL350. At the time of the event we were already cleared direct to 57n010w.

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Original NASA ASRS Text

Title: B767 CREW HAD ALTDEV WHILE OBTAINING ATLANTIC CLRNC FROM EGGX.

Narrative: ALTDEV. I WAS OBTAINING OCEANIC CLRNC ON HEADSET AND THE FO WAS MONITORING ATC AND FLYING ON HEADSET WHEN HE STARTED A CLB FROM FL330 TO FL350. AFTER WRITING DOWN THE CLRNC AND TURNING BACK ON THE #1 RADIO, LONDON ASKED IF WE WERE CLBING. I SAID YES AND ASKED WHAT ALT THEY WANTED. LONDON ADVISED THAT WE HAD CLBED WITHOUT CLRNC AND TO MAINTAIN FL350. THE FO HAD MONITORED THE OCEANIC CLRNC AND WHEN SHANNON GAVE THE TIME AND ALT FOR 5710N OF NOT BEFORE XA42Z AND TO CROSS AT FL350, HE THOUGHT THAT LONDON HAD TOLD US TO CROSS. I WAS NOT MONITORING ATC AND DID NOT KNOW THAT HE CLBED WITHOUT CLRNC UNTIL THE CLB WAS COMPLETE. I HAVE FLOWN WITH THE FO ON SEVERAL OCCASIONS AND HE ALWAYS DOES A FINE JOB. SHANNON SOUNDED LIKE LONDON AND HE SIMPLY MADE AN ERROR. IT DID NOT DAWN ON HIM THAT I WAS ANSWERING SHANNON AND NOT LONDON UNTIL LONDON CTL CALLED US. SUPPLEMENTAL INFO FROM ACN 451910: AT FL330 CAPT WAS GETTING OCEANIC CLRNC FROM SHANWICK WHILE I WAS MONITORING CTR. WHEN OCEANIC CLRNC WAS COMING I TURNED UP THE VOLUME ON THAT FREQ TO THE CLRNC. AFTER THE 57N010W NOT BEFORE XA42Z AND AT FL350. I DID NOT REALIZE THAT THE CLRNC WAS NOT GIVEN BY LONDON CTL AND THOUGHT WE WERE CLRED TO FL350 ANYTIME BEFORE REACHING 010W. WHILE CLBING TO FL350 THE CTLR ASKED ABOUT THE CLB AND WE REPLIED THAT WE WERE CLRED TO FL350. THE CTLR SAID WE WERE NOT, BUT LET US MAINTAIN FL350. AT THE TIME OF THE EVENT WE WERE ALREADY CLRED DIRECT TO 57N010W.

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.