Narrative:

We departed mkc for hpn in the company X departing behind us was the company xx going to mke. The mkc airport radar was down, and approach control radar was being operated out of kansas city ARTCC, some 30 mi south of the normal radar facility, due to closure of the regular facility by the FAA and osha. When switched to center we were instructed to climb to FL230 then were on the same frequency, and due to departure procedures were approximately in the same area. The controller working both of us was fairly busy with other traffic and would use the call sign xx for xx and use X for our aircraft. This call sign was difficult to figure out at first, but after listening for a response from our sister aircraft and getting none, I answered the first time as X and nothing was said by either the controller or our sister aircraft. This procedure was used when we were cleared from FL230 to FL270. The next time the controller came on he requested X 'climb to FL310' and I acknowledged as 'out of FL270 for FL310'. There was no reply from the controller. He cleared xx to FL330 shortly after this. As we were passing through FL280 the controller came on and asked if we were at FL270. I answered that we had been cleared to FL310. He left to a heading of 360, our previous heading was approximately 073. Once we were back at FL270 he cleared us back on course and nothing further was said from either center or ourselves. After this occurred, the controller resumed using more complete call signs. During the descent and turn both the pilot and myself watched carefully for conflicting traffic and did not see any. We were not sure if these instructions were for an actual traffic conflict or for an airspace separation incursion. What the pilot and I think may have happened is that the controller may have gotten the 2 aircraft confused due to similar call signs and similar directions and meant to clear our sister aircraft xx to FL310 but due to the number of aircraft he was working and the brief period of using an incomplete call sign may have gotten the 2 of us confused. Another factor which may have contributed to the cause was that initially the controller was calling us by X then after a couple of transmissions it became X. We are not sure whether this was intentional or whether the controller's microphone was being keyed after he said the first number and all we heard was ____. Questioning the controller as to who the last clearance was meant for, rather than answering and proceeding on would have prevented this occurrence. This has always been my policy in the past and why I did not adhere to it this time I do not know. It definitely reinforced, in my mind, to continue the policy.

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Original NASA ASRS Text

Title: 2 CORPORATE ACFT DEPARTING MKC AND CLBING WHILE ON SAME FREQ HAD SIMILAR IDENTS AND WERE MIXED UP BY ARTCC CTLR.

Narrative: WE DEPARTED MKC FOR HPN IN THE COMPANY X DEPARTING BEHIND US WAS THE COMPANY XX GOING TO MKE. THE MKC ARPT RADAR WAS DOWN, AND APCH CTL RADAR WAS BEING OPERATED OUT OF KANSAS CITY ARTCC, SOME 30 MI S OF THE NORMAL RADAR FACILITY, DUE TO CLOSURE OF THE REGULAR FACILITY BY THE FAA AND OSHA. WHEN SWITCHED TO CENTER WE WERE INSTRUCTED TO CLB TO FL230 THEN WERE ON THE SAME FREQ, AND DUE TO DEP PROCS WERE APPROX IN THE SAME AREA. THE CTLR WORKING BOTH OF US WAS FAIRLY BUSY WITH OTHER TFC AND WOULD USE THE CALL SIGN XX FOR XX AND USE X FOR OUR ACFT. THIS CALL SIGN WAS DIFFICULT TO FIGURE OUT AT FIRST, BUT AFTER LISTENING FOR A RESPONSE FROM OUR SISTER ACFT AND GETTING NONE, I ANSWERED THE FIRST TIME AS X AND NOTHING WAS SAID BY EITHER THE CTLR OR OUR SISTER ACFT. THIS PROC WAS USED WHEN WE WERE CLRED FROM FL230 TO FL270. THE NEXT TIME THE CTLR CAME ON HE REQUESTED X 'CLB TO FL310' AND I ACKNOWLEDGED AS 'OUT OF FL270 FOR FL310'. THERE WAS NO REPLY FROM THE CTLR. HE CLRED XX TO FL330 SHORTLY AFTER THIS. AS WE WERE PASSING THROUGH FL280 THE CTLR CAME ON AND ASKED IF WE WERE AT FL270. I ANSWERED THAT WE HAD BEEN CLRED TO FL310. HE LEFT TO A HDG OF 360, OUR PREVIOUS HDG WAS APPROX 073. ONCE WE WERE BACK AT FL270 HE CLRED US BACK ON COURSE AND NOTHING FURTHER WAS SAID FROM EITHER CENTER OR OURSELVES. AFTER THIS OCCURRED, THE CTLR RESUMED USING MORE COMPLETE CALL SIGNS. DURING THE DSCNT AND TURN BOTH THE PLT AND MYSELF WATCHED CAREFULLY FOR CONFLICTING TFC AND DID NOT SEE ANY. WE WERE NOT SURE IF THESE INSTRUCTIONS WERE FOR AN ACTUAL TFC CONFLICT OR FOR AN AIRSPACE SEPARATION INCURSION. WHAT THE PLT AND I THINK MAY HAVE HAPPENED IS THAT THE CTLR MAY HAVE GOTTEN THE 2 ACFT CONFUSED DUE TO SIMILAR CALL SIGNS AND SIMILAR DIRECTIONS AND MEANT TO CLR OUR SISTER ACFT XX TO FL310 BUT DUE TO THE NUMBER OF ACFT HE WAS WORKING AND THE BRIEF PERIOD OF USING AN INCOMPLETE CALL SIGN MAY HAVE GOTTEN THE 2 OF US CONFUSED. ANOTHER FACTOR WHICH MAY HAVE CONTRIBUTED TO THE CAUSE WAS THAT INITIALLY THE CTLR WAS CALLING US BY X THEN AFTER A COUPLE OF TRANSMISSIONS IT BECAME X. WE ARE NOT SURE WHETHER THIS WAS INTENTIONAL OR WHETHER THE CTLR'S MICROPHONE WAS BEING KEYED AFTER HE SAID THE FIRST NUMBER AND ALL WE HEARD WAS ____. QUESTIONING THE CTLR AS TO WHO THE LAST CLRNC WAS MEANT FOR, RATHER THAN ANSWERING AND PROCEEDING ON WOULD HAVE PREVENTED THIS OCCURRENCE. THIS HAS ALWAYS BEEN MY POLICY IN THE PAST AND WHY I DID NOT ADHERE TO IT THIS TIME I DO NOT KNOW. IT DEFINITELY REINFORCED, IN MY MIND, TO CONTINUE THE POLICY.

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.