Narrative:

We were taxiing from the FBO where we park for the overnight in buf to the main terminal. Taxi instructions were to hold short of runway 5 O taxiway east. After waiting a short time for instructions to cross runway 5, xyz airlines was given clearance to taxi into position and hold on runway 5. The ground controller issued us instructions to cross runway 5. I read back the taxi instructions using our complete call sign and crossed the runway headed for the gate. We checked left and right prior to crossing. On our right, we could see xyz entering runway 5 and a ZZZ aircraft crossing to the same side we were on. ZZZ was on taxiway F and we were on taxiway east. When we safely crossed at taxiway east and started down taxiway a to the gate, ground control asked if that was us on taxiway a. I confirmed that it was. The controller then informed us that we had not been issued crossing instructions. He told us it was for ZZZ. I don't remember the ZZZ flight number. I did inform the ground controller that he had given us instructions to cross and I read them back to him before crossing. He informed us the instructions to cross runway 5 were for ZZZ and that my readback to him was blocked and he did not hear my radio transmission about crossing. We apologized for the mistake. As captain, I assume all the responsibility for the improper runway crossing. Factors that I feel that contributed to this were radio congestion and controller workload. The ground controller was working both ground and tower. Even though I was 99% sure he gave us crossing instructions, I will confirm a second time before crossing, especially whenever there is a lot of radio congestion. It is my belief that a controller should not have to work both tower and ground frequencys, especially during busy times.

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Original NASA ASRS Text

Title: FREQ CONGESTION AND BLOCKING RESULT IN A RWY XING WITHOUT CLRNC AT BUF, NY.

Narrative: WE WERE TAXIING FROM THE FBO WHERE WE PARK FOR THE OVERNIGHT IN BUF TO THE MAIN TERMINAL. TAXI INSTRUCTIONS WERE TO HOLD SHORT OF RWY 5 O TXWY E. AFTER WAITING A SHORT TIME FOR INSTRUCTIONS TO CROSS RWY 5, XYZ AIRLINES WAS GIVEN CLRNC TO TAXI INTO POS AND HOLD ON RWY 5. THE GND CTLR ISSUED US INSTRUCTIONS TO CROSS RWY 5. I READ BACK THE TAXI INSTRUCTIONS USING OUR COMPLETE CALL SIGN AND CROSSED THE RWY HEADED FOR THE GATE. WE CHKED L AND R PRIOR TO XING. ON OUR R, WE COULD SEE XYZ ENTERING RWY 5 AND A ZZZ ACFT XING TO THE SAME SIDE WE WERE ON. ZZZ WAS ON TXWY F AND WE WERE ON TXWY E. WHEN WE SAFELY CROSSED AT TXWY E AND STARTED DOWN TXWY A TO THE GATE, GND CTL ASKED IF THAT WAS US ON TXWY A. I CONFIRMED THAT IT WAS. THE CTLR THEN INFORMED US THAT WE HAD NOT BEEN ISSUED XING INSTRUCTIONS. HE TOLD US IT WAS FOR ZZZ. I DON'T REMEMBER THE ZZZ FLT NUMBER. I DID INFORM THE GND CTLR THAT HE HAD GIVEN US INSTRUCTIONS TO CROSS AND I READ THEM BACK TO HIM BEFORE XING. HE INFORMED US THE INSTRUCTIONS TO CROSS RWY 5 WERE FOR ZZZ AND THAT MY READBACK TO HIM WAS BLOCKED AND HE DID NOT HEAR MY RADIO XMISSION ABOUT XING. WE APOLOGIZED FOR THE MISTAKE. AS CAPT, I ASSUME ALL THE RESPONSIBILITY FOR THE IMPROPER RWY XING. FACTORS THAT I FEEL THAT CONTRIBUTED TO THIS WERE RADIO CONGESTION AND CTLR WORKLOAD. THE GND CTLR WAS WORKING BOTH GND AND TWR. EVEN THOUGH I WAS 99% SURE HE GAVE US XING INSTRUCTIONS, I WILL CONFIRM A SECOND TIME BEFORE XING, ESPECIALLY WHENEVER THERE IS A LOT OF RADIO CONGESTION. IT IS MY BELIEF THAT A CTLR SHOULD NOT HAVE TO WORK BOTH TWR AND GND FREQS, ESPECIALLY DURING BUSY TIMES.

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.