FLC OF AN MLG ACR ACFT CLBED ABOVE ASSIGNED ALT DUE TO A MISUNDERSTANDING OF AN EXPECTED CLB CLRNC.

Narrative

ROUTINE FLT UNTIL AT XA40 AT FL330 NEAR ABQ. I DECIDED TO ASK FOR FL370 FOR FUEL ECONOMY PURPOSES AND REQUESTED SUCH FROM ZAB. A CLRNC WAS RECEIVED AND READ BACK 'TURN L 15 DEGS; VECTORS FOR CLB. MAINTAIN FL370.' BY THEN THE CTLR WAS TALKING TO ANOTHER ACFT AND DID NOT ACKNOWLEDGE MY READBACK. PASSING FL337 A TCASII TA OCCURRED. I RPTED THIS TO ZAB. THE REPLY WAS 'YOU'RE SUPPOSED TO BE AT FL330.' BOTH PLTS IMMEDIATELY REACTED AND A QUICK DSCNT TO FL330 WAS DONE. A FEW MINS LATER I WAS NOTIFIED THAT A POSSIBLE PLTDEV RPT MIGHT BE FILED AND GIVEN A ZAB TELEPHONE NUMBER. I CALLED ON JUL/XX/93 AND LISTENED TO THE TAPE. THE CLRNC ISSUED BY THE CTLR WAS 'TURN L 15 DEGS; VECTORS FOR YOUR CLB; MAINTAIN FL330; EXPECT FL370 WHEN CLR OF TFC.' BOTH PLTS MISHEARD THIS AND MY READBACK WAS MADE FOR A CLB. ALTHOUGH WE WERE NEAR THE END OF A LONG TEDIOUS DAY I DID NOT FEEL UNUSUALLY FATIGUED. THE FACT THAT THE CTLR WAS TALKING TO SEVERAL ACFT IN A SHORT TIME FRAME AND DID NOT RECOGNIZE THE ERROR OF OUR READBACK SEEMS TO BE THE MAIN FACTOR IN THIS INCIDENT. I WAS TOLD BY THE ZAB MGR THAT A CTLR OPERROR INCIDENT RPT HAD BEEN PROCESSED. NO FURTHER INCIDENTS THIS FLT.