Narrative:

During cruise at FL300, center requested a turn 30 degrees at the same time the first officer was having a coughing fit. It was the first officer working the radios as I was flying the leg. I looked at the first officer and wanted to see if he had heard the request and if he was going to respond. He was still coughing, so, as I was told by center, I responded '30 degrees left, flight X,' but made a 30 degree right turn instead. During the next 30 seconds or so, center was giving turn requests to another airline's flight but airline flight Y was not responding. I remember center saying 'flight Y, turn 30 degrees,' but I do not remember the flight number or direction of turn requested by ZME. There were 3 attempts to contact flight Y and I heard no response. Just after the third attempt to contact flight Y, I received instructions from ZME to 'turn left immediately' and 'descend to FL310,' which I did. I turned about 60 degrees left and when beginning the descent received a TA. After a min or so, I climbed back to FL330 and proceeded on course as requested by center. I never saw flight Y. This was a unique combination of errors. My first officer was coughing and sneezing at an alarming rate and was not very helpful with confirming radio calls or instructions. He went home sick the next day. The controller did not give reason for the heading change. Numerous aircraft had been requesting heading changes for WX. I usually receive heading changes for 'in trail spacing,' and did not know this request was for converging traffic at the same altitude. The center did not follow my course change and questioned the direction of my turn. It is much safer to assign a magnetic heading after asking the aircraft the present heading, which is routine. Flight Y was either not on the frequency and should have been or the controller was working numerous frequencys. Since the other aircraft was in close proximity to my aircraft and at the same altitude, I would expect the aircraft to be sharing the same frequency I was sharing with the controller.

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Original NASA ASRS Text

Title: A TURNING THE WRONG DIRECTION BY THE PIC OF A B737 AT FL330 PLACES HIS ACFT IN POTENTIAL CONFLICT WITH ANOTHER ACR FLT AT THE SAME ALT, 80 NM FROM MEM, TN.

Narrative: DURING CRUISE AT FL300, CTR REQUESTED A TURN 30 DEGS AT THE SAME TIME THE FO WAS HAVING A COUGHING FIT. IT WAS THE FO WORKING THE RADIOS AS I WAS FLYING THE LEG. I LOOKED AT THE FO AND WANTED TO SEE IF HE HAD HEARD THE REQUEST AND IF HE WAS GOING TO RESPOND. HE WAS STILL COUGHING, SO, AS I WAS TOLD BY CTR, I RESPONDED '30 DEGS L, FLT X,' BUT MADE A 30 DEG R TURN INSTEAD. DURING THE NEXT 30 SECONDS OR SO, CTR WAS GIVING TURN REQUESTS TO ANOTHER AIRLINE'S FLT BUT AIRLINE FLT Y WAS NOT RESPONDING. I REMEMBER CTR SAYING 'FLT Y, TURN 30 DEGS,' BUT I DO NOT REMEMBER THE FLT NUMBER OR DIRECTION OF TURN REQUESTED BY ZME. THERE WERE 3 ATTEMPTS TO CONTACT FLT Y AND I HEARD NO RESPONSE. JUST AFTER THE THIRD ATTEMPT TO CONTACT FLT Y, I RECEIVED INSTRUCTIONS FROM ZME TO 'TURN L IMMEDIATELY' AND 'DESCEND TO FL310,' WHICH I DID. I TURNED ABOUT 60 DEGS L AND WHEN BEGINNING THE DSCNT RECEIVED A TA. AFTER A MIN OR SO, I CLBED BACK TO FL330 AND PROCEEDED ON COURSE AS REQUESTED BY CTR. I NEVER SAW FLT Y. THIS WAS A UNIQUE COMBINATION OF ERRORS. MY FO WAS COUGHING AND SNEEZING AT AN ALARMING RATE AND WAS NOT VERY HELPFUL WITH CONFIRMING RADIO CALLS OR INSTRUCTIONS. HE WENT HOME SICK THE NEXT DAY. THE CTLR DID NOT GIVE REASON FOR THE HDG CHANGE. NUMEROUS ACFT HAD BEEN REQUESTING HDG CHANGES FOR WX. I USUALLY RECEIVE HDG CHANGES FOR 'IN TRAIL SPACING,' AND DID NOT KNOW THIS REQUEST WAS FOR CONVERGING TFC AT THE SAME ALT. THE CTR DID NOT FOLLOW MY COURSE CHANGE AND QUESTIONED THE DIRECTION OF MY TURN. IT IS MUCH SAFER TO ASSIGN A MAGNETIC HDG AFTER ASKING THE ACFT THE PRESENT HDG, WHICH IS ROUTINE. FLT Y WAS EITHER NOT ON THE FREQ AND SHOULD HAVE BEEN OR THE CTLR WAS WORKING NUMEROUS FREQS. SINCE THE OTHER ACFT WAS IN CLOSE PROX TO MY ACFT AND AT THE SAME ALT, I WOULD EXPECT THE ACFT TO BE SHARING THE SAME FREQ I WAS SHARING WITH THE CTLR.

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.