Narrative:

Shortly after checking on with ZOA; I realized that we had air carrier Y on frequency; both having departed from sfo; both headed to mexico. I prepared myself to be extra alert as I would be dealing with the similar call signs through a majority of the flight. Upon reaching ZLA; I discovered air carrier Z on frequency; also going to mexico. Now we've got every single airborne jet on the frequency headed to mexico with 2 of the 3 call sign numbers the same -- air carrier X; air carrier Y; and air carrier Z. All involved were careful; and the flts continued uneventfully. Not having all the mexico flts launch with similar numbers would certainly minimize the potential for taking somebody else's clearance en route inadvertently.

Google
 

Original NASA ASRS Text

Title: B737 FO STATES CONCERNS ABOUT COMPANY UTILIZING SIMILAR CALL SIGNS FOR ACFT DEPARTING AT SAME TIME; SAME DIRECTION OF FLT AND CLOSE DESTS.

Narrative: SHORTLY AFTER CHKING ON WITH ZOA; I REALIZED THAT WE HAD ACR Y ON FREQ; BOTH HAVING DEPARTED FROM SFO; BOTH HEADED TO MEXICO. I PREPARED MYSELF TO BE EXTRA ALERT AS I WOULD BE DEALING WITH THE SIMILAR CALL SIGNS THROUGH A MAJORITY OF THE FLT. UPON REACHING ZLA; I DISCOVERED ACR Z ON FREQ; ALSO GOING TO MEXICO. NOW WE'VE GOT EVERY SINGLE AIRBORNE JET ON THE FREQ HEADED TO MEXICO WITH 2 OF THE 3 CALL SIGN NUMBERS THE SAME -- ACR X; ACR Y; AND ACR Z. ALL INVOLVED WERE CAREFUL; AND THE FLTS CONTINUED UNEVENTFULLY. NOT HAVING ALL THE MEXICO FLTS LAUNCH WITH SIMILAR NUMBERS WOULD CERTAINLY MINIMIZE THE POTENTIAL FOR TAKING SOMEBODY ELSE'S CLRNC ENRTE INADVERTENTLY.

Data retrieved from NASA's ASRS site as of January 2009 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.