Narrative:

As you can see by the enclosed list of the bank of flight numbers the possibility increases of mistaken call signs due to similar numbers. Especially since all begin with company identify. I almost initiated a climb from 2500 MSL based on what I thought were climb instructions for company. The controllers have enough to deal with in terms of the number and volume of departures. With the recent increase in flts in and out of ind, this use of similar call signs will eventually lead to a big mistake, either by controllers or crew members.

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Original NASA ASRS Text

Title: COMMUTER ACFT STATES CONCERN REF SIMILAR CALL SIGNS OF COMPANY ACFT.

Narrative: AS YOU CAN SEE BY THE ENCLOSED LIST OF THE BANK OF FLT NUMBERS THE POSSIBILITY INCREASES OF MISTAKEN CALL SIGNS DUE TO SIMILAR NUMBERS. ESPECIALLY SINCE ALL BEGIN WITH COMPANY IDENT. I ALMOST INITIATED A CLB FROM 2500 MSL BASED ON WHAT I THOUGHT WERE CLB INSTRUCTIONS FOR COMPANY. THE CTLRS HAVE ENOUGH TO DEAL WITH IN TERMS OF THE NUMBER AND VOLUME OF DEPS. WITH THE RECENT INCREASE IN FLTS IN AND OUT OF IND, THIS USE OF SIMILAR CALL SIGNS WILL EVENTUALLY LEAD TO A BIG MISTAKE, EITHER BY CTLRS OR CREW MEMBERS.

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.