Narrative:

On apr/xa/99 at about XA50Z, near the seminole VOR, we were assigned a heading of 310 degrees and climb instructions to FL280. While climbing through the mid 20's the controller instructed us to climb to FL350. I replied back to the controller that we were to climb and maintain FL350 and acknowledged my tail number. Since the controller never replied back that our climb instructions were wrong, we set FL350 in the altitude capture window. While climbing through FL270 our TCASII advised us of traffic at our 12 - 2 O'clock position and above us. At this point we slowed our climb rate and looked for a visual of the traffic. While passing through about FL285 our TCASII gave us an RA warning to descend. At this time, we stopped our ascent and started a descent. At the same time also we acquired visual with the traffic and received a panic reply from the controller to descend to FL280 and traffic at 12 O'clock. I replied back to the controller confirming we had a TCASII alert and traffic in sight and that we had already started a descent. Within a few seconds, we leveled off at FL280 and the controller advised us of another aircraft at 12 O'clock and FL290. The controller stated that we were to have climbed and maintained FL280 because of that traffic at FL290. I replied that we had that aircraft in sight and that he had given us instruction to climb and maintain FL350 and that I had called it back to him. I then asked the controller, after the traffic passed by, if he wanted us to climb to FL350 or stay at FL280. He replied, 'stay at FL280,' so we did. Shortly, we were handed off to the next controller and we continued on the flight with no other problems. My feeling of what caused the problem was that the controller never acknowledged my reply to climb to FL350 when it was first issued. I have also learned that there was also a second company jet on frequency with similar tail number/call sign. The controller never advised us of company aircraft with similar call signs on frequency. Had the controller advised us of the other company aircraft and had he replied back, that our initial response to climb to FL350 was incorrect, then there would have not been an incident.

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Original NASA ASRS Text

Title: A CPR FLC IN A BE40 CLBED ABOVE THEIR ASSIGNED ALT WHEN THEY MISTOOK AN ALT ASSIGNMENT INTENDED FOR A SIMILAR NUMBERED COMPANY ACFT FOR THEIR OWN. THIS LED TO A POTENTIAL CONFLICT WITH AN UNIDENTED TWIN ENG ACFT.

Narrative: ON APR/XA/99 AT ABOUT XA50Z, NEAR THE SEMINOLE VOR, WE WERE ASSIGNED A HDG OF 310 DEGS AND CLB INSTRUCTIONS TO FL280. WHILE CLBING THROUGH THE MID 20'S THE CTLR INSTRUCTED US TO CLB TO FL350. I REPLIED BACK TO THE CTLR THAT WE WERE TO CLB AND MAINTAIN FL350 AND ACKNOWLEDGED MY TAIL NUMBER. SINCE THE CTLR NEVER REPLIED BACK THAT OUR CLB INSTRUCTIONS WERE WRONG, WE SET FL350 IN THE ALT CAPTURE WINDOW. WHILE CLBING THROUGH FL270 OUR TCASII ADVISED US OF TFC AT OUR 12 - 2 O'CLOCK POS AND ABOVE US. AT THIS POINT WE SLOWED OUR CLB RATE AND LOOKED FOR A VISUAL OF THE TFC. WHILE PASSING THROUGH ABOUT FL285 OUR TCASII GAVE US AN RA WARNING TO DSND. AT THIS TIME, WE STOPPED OUR ASCENT AND STARTED A DSCNT. AT THE SAME TIME ALSO WE ACQUIRED VISUAL WITH THE TFC AND RECEIVED A PANIC REPLY FROM THE CTLR TO DSND TO FL280 AND TFC AT 12 O'CLOCK. I REPLIED BACK TO THE CTLR CONFIRMING WE HAD A TCASII ALERT AND TFC IN SIGHT AND THAT WE HAD ALREADY STARTED A DSCNT. WITHIN A FEW SECONDS, WE LEVELED OFF AT FL280 AND THE CTLR ADVISED US OF ANOTHER ACFT AT 12 O'CLOCK AND FL290. THE CTLR STATED THAT WE WERE TO HAVE CLBED AND MAINTAINED FL280 BECAUSE OF THAT TFC AT FL290. I REPLIED THAT WE HAD THAT ACFT IN SIGHT AND THAT HE HAD GIVEN US INSTRUCTION TO CLB AND MAINTAIN FL350 AND THAT I HAD CALLED IT BACK TO HIM. I THEN ASKED THE CTLR, AFTER THE TFC PASSED BY, IF HE WANTED US TO CLB TO FL350 OR STAY AT FL280. HE REPLIED, 'STAY AT FL280,' SO WE DID. SHORTLY, WE WERE HANDED OFF TO THE NEXT CTLR AND WE CONTINUED ON THE FLT WITH NO OTHER PROBS. MY FEELING OF WHAT CAUSED THE PROB WAS THAT THE CTLR NEVER ACKNOWLEDGED MY REPLY TO CLB TO FL350 WHEN IT WAS FIRST ISSUED. I HAVE ALSO LEARNED THAT THERE WAS ALSO A SECOND COMPANY JET ON FREQ WITH SIMILAR TAIL NUMBER/CALL SIGN. THE CTLR NEVER ADVISED US OF COMPANY ACFT WITH SIMILAR CALL SIGNS ON FREQ. HAD THE CTLR ADVISED US OF THE OTHER COMPANY ACFT AND HAD HE REPLIED BACK, THAT OUR INITIAL RESPONSE TO CLB TO FL350 WAS INCORRECT, THEN THERE WOULD HAVE NOT BEEN AN INCIDENT.

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.