B757-200 FO CANNOT CONVINCE THE PIC ON TAXI OUT THAT NEW PERFORMANCE DATA MUST BE OBTAINED FOR A RWY LENGTH AVAILABLE ADJUSTMENT AT JFK; NY.

Narrative

PROB: QUESTIONABLE TKOF PERFORMANCE DATA. DURING PREFLT; I BROUGHT TO THE CAPT'S ATTN A NOTAM REGARDING OUR TKOF RWY; LAST 3872 FT CLOSED/10700 FT AVAILABLE. THIS SIT WAS NOT ADDRESSED ON OUR TKOF PERFORMANCE DATA. THE CAPT INSISTED THAT THIS WAS IN FACT INCORPORATED INTO THE AVAILABLE TKOF DATA. I POINTED OUT TO HIM THAT THIS DATA REFED A RWY AVAILABLE LENGTH OF OVER 14000 FT. I ASKED IF I COULD SEND DISPATCH A MESSAGE REQUESTING UPDATED NUMBERS. HE SAID IT WAS NOT NECESSARY; BUT I COULD IF I WANTED TO AND HE FURTHER INSISTED THAT OUR DATA WAS VALID. I SENT THE MESSAGE; BUT NEVER RECEIVED THE INFO. THE CAPT WAS CLR THAT HE WOULD NOT TAKE A DELAY FOR THIS AND REFED DATA FOR THE SAME RWY OPPOSITE DIRECTION WITH 10700 FT AVAILABLE AND SHOWED AT 26000 LB PERFORMANCE MARGIN. I INFORMED HIM THAT THIS WAS ONLY VALID IF THE RWY HAD NO GRADE. FORTUNATELY; JFK IS QUITE LEVEL. I FURTHER INFORMED HIM THAT MODIFICATION TO OUR EXISTING DATA SHOWED US ILLEGAL AND OFFERED TO CALCULATE THE DATA MANUALLY. BY NOW; WE WERE #1 FOR TKOF AND HE HAD ALREADY EMPHASIZED THAT HE WOULD NOT ACCEPT A DELAY. HE FURTHER REFED OUR EXISTING DATA AND INSISTED IT WAS ADEQUATE. ALTHOUGH THE OP WAS VERY SAFE AND A VERY LARGE PERFORMANCE MARGIN EXISTED (OVER 25000 LBS) THE MEANS OF QUANTIFYING THIS WAS NOT ACCORDING TO STANDARD METHODS. ALTHOUGH THIS IS A VERY MINOR TECHNICALITY; IT IS STILL IN CONTRADICTION TO SOP AND REPRESENTS A CRM FAILURE. I WAS INSISTENT AS I COULD BE WITHOUT CREATING A NEGATIVE ENVIRONMENT. IF THIS WERE A CRITICAL SAFETY ISSUE; I WOULD HAVE BEEN EVEN MORE DIRECTIVE. IT WOULD BE USEFUL TO HAVE AN FAA PROC SUCH AS CRM 'CODE WORD' SUCH AS THE MIL'S 'TIME-OUT' TO STOP OP AND RESOLVE CONFLICT.