Narrative:

Our flight number was abc. A company flight number was aac. On 2 different occasions, I responded for aac. Once, I verified the call and prevented the error. On the second occasion, the flight engineer caught my response to center and it was corrected west/O responding to the action requested. As both aac and abc switched to approach the problem continued and became more critical. Each of us were on similar tracks for the south landing. As such, similar vectors and altitudes were being transmitted. We were in trail of aac and VMC with the airport in sight. Approach had kept us high and we were expediting a lower altitude with an approach clearance at any time. Approach issued the following clearance 'turn left to 210, maintain 3000' until established, 170 KTS to penzz and contact the tower at penzz 128.2.' knowing that we were high, the captain began executing the instructions. Before I read the clearance back, I asked if that was for us, abc, only because we had trouble with it earlier. Approach informed us that it was not. We didn't violate any rules but under different conditions, it may have been hazardous. I talked with the other crew, aac, and they found the same problem with the call sign. I recommend that airlines be made aware of this problem when numbering flts. I find that on a 3 digit flight number, the first and third number are most readily heard and the middle digit gets washed out.

Related reports:

Google
 

Original NASA ASRS Text

Title: LGT BEGAN DESCENT WITHOUT RECEIVING CLRNC.

Narrative: OUR FLT NUMBER WAS ABC. A COMPANY FLT NUMBER WAS AAC. ON 2 DIFFERENT OCCASIONS, I RESPONDED FOR AAC. ONCE, I VERIFIED THE CALL AND PREVENTED THE ERROR. ON THE SECOND OCCASION, THE FE CAUGHT MY RESPONSE TO CENTER AND IT WAS CORRECTED W/O RESPONDING TO THE ACTION REQUESTED. AS BOTH AAC AND ABC SWITCHED TO APCH THE PROB CONTINUED AND BECAME MORE CRITICAL. EACH OF US WERE ON SIMILAR TRACKS FOR THE S LNDG. AS SUCH, SIMILAR VECTORS AND ALTS WERE BEING XMITTED. WE WERE IN TRAIL OF AAC AND VMC WITH THE ARPT IN SIGHT. APCH HAD KEPT US HIGH AND WE WERE EXPEDITING A LOWER ALT WITH AN APCH CLRNC AT ANY TIME. APCH ISSUED THE FOLLOWING CLRNC 'TURN LEFT TO 210, MAINTAIN 3000' UNTIL ESTABLISHED, 170 KTS TO PENZZ AND CONTACT THE TWR AT PENZZ 128.2.' KNOWING THAT WE WERE HIGH, THE CAPT BEGAN EXECUTING THE INSTRUCTIONS. BEFORE I READ THE CLRNC BACK, I ASKED IF THAT WAS FOR US, ABC, ONLY BECAUSE WE HAD TROUBLE WITH IT EARLIER. APCH INFORMED US THAT IT WAS NOT. WE DIDN'T VIOLATE ANY RULES BUT UNDER DIFFERENT CONDITIONS, IT MAY HAVE BEEN HAZARDOUS. I TALKED WITH THE OTHER CREW, AAC, AND THEY FOUND THE SAME PROB WITH THE CALL SIGN. I RECOMMEND THAT AIRLINES BE MADE AWARE OF THIS PROB WHEN NUMBERING FLTS. I FIND THAT ON A 3 DIGIT FLT NUMBER, THE FIRST AND THIRD NUMBER ARE MOST READILY HEARD AND THE MIDDLE DIGIT GETS WASHED OUT.

Data retrieved from NASA's ASRS site as of August 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.