AN ACR MD80 FLC RPTS THAT THEY RECEIVED AN INSTRUCTION FOR AN EVASIVE TURN FOR TFC AND LATER SAW A COMPANY B757 PASS ABOVE AND TO THE L OF THEIR ACFT.

Narrative

THIS INCIDENT STARTED WHEN WE WERE W OF THE LAKE CHARLES VOR; HEADED E; CLBING THROUGH FL290 TO OUR ASSIGNED ALT OF FL330. THE CTLR CALLED US AND SAID TURN TO A HDG OF ABOUT 170 DEGS AS QUICK AS YOU CAN. I WAS FLYING THE AIRPLANE; SO I QUICKLY ROTATED THE HDG SELECTOR TO 170 DEGS AND INCREASED THE BANK SELECTOR TO 30 DEGS. AT ABOUT THE SAME TIME THE CTLR ADDED GO AHEAD AND GO BACK DOWN TO FL290; SO I PROMPTLY CHANGED THE CLB INTO A DSCNT. THE CTLR NEVER SOUNDED TO US AS IF THIS WAS A CRITICAL SIT. THESE CALLS WERE SO UNUSUAL THOUGH; THAT I TRIED TO REACT TO IT AS IF IT WERE A HAZARDOUS SIT WITHOUT UNDULY ALARMING THE PAX. DURING THIS PERIOD; WE OBSERVED A TCASII TARGET AT 12 O'CLOCK; 1500 FT ABOVE US; AND MOMENTS LATER SAW WHAT LOOKED LIKE ONE OF OUR B757'S PASSING ABOVE AND SLIGHTLY TO OUR L. IF WE HAD NOT STARTED THE R TURN; WE MIGHT HAVE PASSED DIRECTLY UNDER THIS ACFT. WE WERE FAR ENOUGH BELOW THE B757 THAT I DO NOT BELIEVE THERE WAS A COLLISION HAZARD; BUT I AM SURE THAT WE HAD LESS THAN THE REQUIRED SEPARATION THE CTLR NEEDED. AFTER WE HAD PASSED THE OTHER ACFT; THE CTLR RECLRED US ON COURSE AND BACK UP TO FL330. THE CTLR DID NOT EXPLAIN THE INCIDENT; AND THEY HANDED US OFF TO A DIFFERENT SECTOR A SHORT TIME LATER.