Narrative:

We landed on 8L in iah. Exited the runway; taxied down taxiway np where we proceeded to hold short of 8R behind a 747. As we stopped on np we were told by tower to expect an expedited crossing clearance. They gave the 747 clearance to cross and we proceeded up to and stopped about 10 feet short of hold line for 8R. We sat there and waited maybe a minute or two for landing traffic. Then the tower controller came on and gave us an extremely quick and what seemed like to me a very garbled clearance to cross 8R. I immediately asked the captain if that was for us. He said yes and was in the process of pushing up the thrust levers. I then proceeded to ask the tower 'confirm [flight number] cleared to cross 8R?' I got an immediate affirmative followed by literally in the same breath 'hold short of 8R'. When the captain and I heard 'hold short' both of us stepped on the brakes at the same time coming to a rather abrupt and immediate stop; but by this time we were roughly 5-10 feet past the hold short line. My response over the radio milliseconds after we stopped was in effect 'but we've already crossed the hold short line'.the response by the tower was 'no worries; [flight number] go-around'. The plane that went around I'm guessing was around 800-1000ft from touchdown. At no time was there any risk of collision and if we hadn't been told to stop; I feel like we would have expedited across the runway without incident. On the taxi in I asked ground for a tower number to discuss the situation. In the conversation that the captain had with the tower supervisor after we blocked in; it seems that confusion arose from me asking for a verification of the clearance; which I did not hear a flight number for. The tower sup said we took too long to respond even though we were initially given an affirmative to cross by the controller at the time. The whole situation seemed to have been unnecessarily rushed even though we were expecting the expedited crossing clearance. The whole event happened so fast that it felt like 45 seconds to a minute if that.

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Original NASA ASRS Text

Title: A320 First Officer reported they experienced a runway incursion at IAH when they misunderstood an ATC clearance.

Narrative: We landed on 8L in IAH. Exited the runway; taxied down taxiway NP where we proceeded to hold short of 8R behind a 747. As we stopped on NP we were told by tower to expect an expedited crossing clearance. They gave the 747 clearance to cross and we proceeded up to and stopped about 10 feet short of hold line for 8R. We sat there and waited maybe a minute or two for landing traffic. Then the Tower controller came on and gave us an extremely quick and what seemed like to me a very garbled clearance to cross 8R. I immediately asked the Captain if that was for us. He said yes and was in the process of pushing up the thrust levers. I then proceeded to ask the Tower 'confirm [flight number] cleared to cross 8R?' I got an immediate affirmative followed by literally in the same breath 'hold short of 8R'. When the Captain and I heard 'hold short' both of us stepped on the brakes at the same time coming to a rather abrupt and immediate stop; but by this time we were roughly 5-10 feet past the hold short line. My response over the radio milliseconds after we stopped was in effect 'but we've already crossed the hold short line'.The response by the Tower was 'no worries; [flight number] go-around'. The plane that went around I'm guessing was around 800-1000ft from touchdown. At no time was there any risk of collision and if we hadn't been told to stop; I feel like we would have expedited across the runway without incident. On the taxi in I asked ground for a Tower number to discuss the situation. In the conversation that the Captain had with the Tower supervisor after we blocked in; it seems that confusion arose from me asking for a verification of the clearance; which I did not hear a flight number for. The Tower sup said we took too long to respond even though we were initially given an affirmative to cross by the controller at the time. The whole situation seemed to have been unnecessarily rushed even though we were expecting the expedited crossing clearance. The whole event happened so fast that it felt like 45 seconds to a minute if that.

Data retrieved from NASA's ASRS site 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.