Narrative:

Approximately 10 mi southeast of the cha airport, level at 10000 ft MSL, while on a vector of 160 degree heading, we received a clearance from cha departure to 'turn left on course and contact ZTL on 133.1.' after reading back the clearance, the controller came back and said 'disregard, stay with me.' we assumed that mean to continue the left turn and stay with him on his frequency 125.1. I asked the PNF to verify what the controller meant by 'turn left on course' and to ask him for direct spa which was a fix further into the flight. The PNF tried at least 3 times to verify the clearance and was not successful at reaching the controller. Apparently, the controller was working more than 1 frequency. After approximately 90 degrees of turn to the left from the 160 degree heading, the cha controller came back and directed us to make an immediate right turn to a 180 degree heading. We complied and again asked for verification for the initial clearance, at which point the controller said that he had negated the clearance right after he had given it to us. I feel that the controller's us of nonstandard phraseology was the main contributing factor towards this incident. Had he said 'disregard, maintain 160 degree heading, and stay with me' the incident would not have occurred.

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Original NASA ASRS Text

Title: A CITATION 560 CPR CAPT RPTED THAT A CHA TRACON CTLR'S NON STANDARD PHRASEOLOGY CAUSED CONFUSION WHICH COULD NOT BE CLRED UP IN A TIMELY FASHION DUE TO FREQ CONGESTION.

Narrative: APPROX 10 MI SE OF THE CHA ARPT, LEVEL AT 10000 FT MSL, WHILE ON A VECTOR OF 160 DEG HDG, WE RECEIVED A CLRNC FROM CHA DEP TO 'TURN L ON COURSE AND CONTACT ZTL ON 133.1.' AFTER READING BACK THE CLRNC, THE CTLR CAME BACK AND SAID 'DISREGARD, STAY WITH ME.' WE ASSUMED THAT MEAN TO CONTINUE THE L TURN AND STAY WITH HIM ON HIS FREQ 125.1. I ASKED THE PNF TO VERIFY WHAT THE CTLR MEANT BY 'TURN L ON COURSE' AND TO ASK HIM FOR DIRECT SPA WHICH WAS A FIX FURTHER INTO THE FLT. THE PNF TRIED AT LEAST 3 TIMES TO VERIFY THE CLRNC AND WAS NOT SUCCESSFUL AT REACHING THE CTLR. APPARENTLY, THE CTLR WAS WORKING MORE THAN 1 FREQ. AFTER APPROX 90 DEGS OF TURN TO THE L FROM THE 160 DEG HDG, THE CHA CTLR CAME BACK AND DIRECTED US TO MAKE AN IMMEDIATE R TURN TO A 180 DEG HDG. WE COMPLIED AND AGAIN ASKED FOR VERIFICATION FOR THE INITIAL CLRNC, AT WHICH POINT THE CTLR SAID THAT HE HAD NEGATED THE CLRNC RIGHT AFTER HE HAD GIVEN IT TO US. I FEEL THAT THE CTLR'S US OF NONSTANDARD PHRASEOLOGY WAS THE MAIN CONTRIBUTING FACTOR TOWARDS THIS INCIDENT. HAD HE SAID 'DISREGARD, MAINTAIN 160 DEG HDG, AND STAY WITH ME' THE INCIDENT WOULD NOT HAVE OCCURRED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.