Narrative:

After departing yyz en route to ord, just as we leveled off at FL350, we took a clearance to FL310. Our readback was not acknowledged and after descending 200', I asked the first officer to reconfirm. 3 calls later we got a reply that it wasn't for us, but since we had left FL350 (200') we were cleared to FL330. As we listened, we heard an X airline X67 and we were Y airline Y67 and noticed the controller was leaving off the company prefix and we were apparently hearing X7 as Y67. Since the beginning of sept, I have noticed an increase of no prefix and no confirmations of readbacks, especially from high altitude centers we get used to this as it becomes commonplace. We had another on this very flight of the center controller calling repeatedly for Y YB6. We answered and asked for confirmation. He at first said, 'affirmative,' but changed to Y Y37. Enough said!

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Original NASA ASRS Text

Title: REPORTER INDICATES A GROWING TENDENCY FOR ARTCC CTLRS TO OMIT THE AIRLINE IDENTIFIER IN COMMUNICATING WITH FLTS.

Narrative: AFTER DEPARTING YYZ ENRTE TO ORD, JUST AS WE LEVELED OFF AT FL350, WE TOOK A CLRNC TO FL310. OUR READBACK WAS NOT ACKNOWLEDGED AND AFTER DSNDING 200', I ASKED THE F/O TO RECONFIRM. 3 CALLS LATER WE GOT A REPLY THAT IT WASN'T FOR US, BUT SINCE WE HAD LEFT FL350 (200') WE WERE CLRED TO FL330. AS WE LISTENED, WE HEARD AN X AIRLINE X67 AND WE WERE Y AIRLINE Y67 AND NOTICED THE CTLR WAS LEAVING OFF THE COMPANY PREFIX AND WE WERE APPARENTLY HEARING X7 AS Y67. SINCE THE BEGINNING OF SEPT, I HAVE NOTICED AN INCREASE OF NO PREFIX AND NO CONFIRMATIONS OF READBACKS, ESPECIALLY FROM HIGH ALT CENTERS WE GET USED TO THIS AS IT BECOMES COMMONPLACE. WE HAD ANOTHER ON THIS VERY FLT OF THE CENTER CTLR CALLING REPEATEDLY FOR Y YB6. WE ANSWERED AND ASKED FOR CONFIRMATION. HE AT FIRST SAID, 'AFFIRMATIVE,' BUT CHANGED TO Y Y37. ENOUGH SAID!

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.