A B747-400 FLC FLYING IN NFFF AIRSPACE; CLBS TO FL350 PREMATURELY.

Narrative

AT APPROX XX35Z THE CAPT (PNF) REQUESTED A CLB FROM FL310 TO FL350. AT XX39Z WE WERE CLRED TO 'AT XX08 CLB TO AND MAINTAIN FL350.' AT THIS TIME WE WERE USING CPDLC (FANS) FOR COM; SO WE PRINTED THIS CLRNC AND BOTH READ THE CLRNC. FOR SOME REASON; WHICH WE BOTH CONTRIBUTE TO FATIGUE; WE MISSED THE CONTINGENCY 'AT YY08...' AND CLBED RIGHT AWAY. AT XY54 I SENT A MESSAGE 'LEVEL FL350' AND ABOUT THAT TIME CHANGED SEATS WITH THE RELIEF PLT. AT XY04Z THE PLTS IN THE SEAT SENT A POS RPT WHICH INCLUDED THE FLT LEVEL AFTER WHICH THEY RECEIVED A MESSAGE FROM NADI CTR THAT READ 'YOU WERE NOT CLRED AT FL350 UNTIL XY08.' BASICALLY WE HAD CLBED APPROX 26-28 MINS EARLY. BOTH THE CAPT AND I (PF) WERE VERY TIRED WHEN THIS INCIDENT OCCURRED. WE HAD BEEN FLYING FOR ABOUT 5 1/2 HRS AND IT WAS ABOUT ZZ30 IN OUR HOME TOWNS. IT WAS RIGHT BEFORE WE WERE TO TAKE OUR BREAK. WE BOTH ARE CERTAIN THAT WE WOULD NOT HAVE MISSED THIS CONTINGENCY IF WE WERE NOT TIRED. I REALLY FEEL THAT CONTINGENCY CLRNCS SHOULD NOT BE GIVEN OVER FANS AND ESPECIALLY THIS TIME OF NIGHT WHEN CREWS ARE TIRED. I DON'T EXCUSE OUR ERROR AND DIDN'T THINK THIS WOULD EVER OCCUR TO ME. SUPPLEMENTAL INFO FROM ACN 426344: ACTION IS BEING TAKEN AGAINST US BY THE FAA AND MY PERSONAL FEELINGS ARE THAT I AM EXTREMELY UPSET WITH FANS CONDITIONAL CLRNCS. I AM GOING TO REJECT ANY I RECEIVE. THE PROB LIES WITH PHRASEOLOGY. THEY SHOULD STATE; 'MAINTAIN FL330 THEN STATE AT XY08 CLB AND MAINTAIN FL350.' THAT WOULD HAVE SOLVED THE PROB.