CREW OF AN SMT CHARTER JET ADMITTED POOR CRM WHEN DEVIATING FROM ASSIGNED ALT. FO CITES LANGUAGE BARRIER AS A POSSIBLE CONTRIBUTING FACTOR.

Narrative

WE WERE ON VECTORS FOR QUEBEC CITY (CYQB). CTLR STATED; 'DSND AND MAINTAIN 6000 FT; TURN L 15 DEGS.' I READ THIS BACK; STARTED CALCULATING WHAT HDG THIS WOULD BE (WITH A 5 DEG DISCREPANCY BTWN L AND R HDG INDICATORS); AND HEARD THE CAPT REPLY; '5000 FT; 15 DEGS L.' I ASSUMED THAT I MUST HAVE MISHEARD THE ALT AND THAT THE CAPT HAD IT CORRECT. I DID NOT CHALLENGE OR VERIFY THE ALT. ON REACHING 5100 FT; ATC ADVISED US TO 'CLB TO 6000 FT FOR TFC.' I FEEL THAT I SHOULD HAVE VERIFIED THE ALT. I ALSO FEEL THAT SUCH AN EVENT CAN BE AVOIDED THROUGH PROPER CRM TECHNIQUES. ON BOTH THE FLT INTO AND THEN OUT OF CANADA; PARTICULARLY WITH REGARD TO THE FRENCH SPEAKING CTLR; I (AS THE PNF AND RADIO OPERATOR) HAD SEVERAL OCCURRENCES WHERE CTLRS GAVE ME INSTRUCTIONS; WHICH I ACCURATELY READ BACK; THEN THE CTLR WOULD GIVE DIFFERENT INSTRUCTIONS. FOR EXAMPLE; PRIOR TO THE RETURN FLT; QUEBEC CITY CLRNC GAVE ME A SQUAWK CODE OF 'WXZZ.' I READ BACK 'WXZZ' AND THE REST OF THE CLRNC WHICH THE CTLR CONFIRMED. THEN; UPON CONTACTING DEP CTL; I WAS ADVISED (IN A RATHER CONDESCENDING TONE) TO SQUAWK 'WYZZ' NOT 'WXZZ.' THE LANGUAGE BARRIER MAKES THINGS TRICKY ENOUGH WITHOUT THERE BEING AN 'ATTITUDE BARRIER.'