Narrative:

Upon landing and first officer using full reverse the tower controller instructed us to use the 'forward high speed,' but we both heard K4 high speed (which is the reverse high speed). Tower asked us to contact them upon reaching the gate. It was a misunderstanding due to loud noise in the cockpit (reversers full) and 4 versus forward high speed.

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Original NASA ASRS Text

Title: AN A320 CREW, AFTER LNDG AT IAD, MISCONSTRUED ATC'S INSTRUCTIONS, EXITING THE RWY USING THE REVERSE HIGH SPD, MUCH TO THE CHAGRIN OF THE CTLRS.

Narrative: UPON LNDG AND FO USING FULL REVERSE THE TWR CTLR INSTRUCTED US TO USE THE 'FORWARD HIGH SPD,' BUT WE BOTH HEARD K4 HIGH SPD (WHICH IS THE REVERSE HIGH SPD). TWR ASKED US TO CONTACT THEM UPON REACHING THE GATE. IT WAS A MISUNDERSTANDING DUE TO LOUD NOISE IN THE COCKPIT (REVERSERS FULL) AND 4 VERSUS FORWARD HIGH SPD.

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.