Narrative:

I was working local west (lw) so I was working departures on 15R/left. We are on an east flow meaning landing from the west to the east. North departures were going to runway 9. We had been told that we would also have 3 arrivals to runway 9. The final for runway 9 crosses both 15L and 15R. The last arrival was a B737. I continued rolling departures in front of him until he got about 2 miles west of 15R. I may not have told all aircraft that traffic was landing the crossing runway when I line up and waited them. I don't recall. Anyway; I put [an E170] on 15L and [the B737] on 15R and waited for the arrival to pass. As soon as he did pass; I cleared them for takeoff. It was night time already so seeing the type of aircraft out the window was impossible until about a 1/2 mile final or so. The airplane looked pretty big. I looked again at the display and the asde as well. All appeared normal. Something didn't look right though. The plane was huge! I said; 'what kind of plane is that?! It is not a 737.' I rolled no more departures until I was sure. The local south (ls) guy asked the pilot and he said he was a 767; yes a heavy. So here I just rolled two departures under his wake. The supervisor in charge at the time began to track down what had happened. You remember a while back we had a issue with a mismarked aircraft travel across the country. Thank goodness this was just in houston approach airspace. In the time I took between filing this report back on position the other supervisor (not the one in charge at the time of the issue) said that someone at I90 inadvertently deleted the type aircraft and then put him back in as a 737 instead of a 767. Several things could have clued us in that this aircraft was a heavy. One; the ramp monitor at local south (ls) showed him as a heavy. I couldn't see it from where I was working; but the ls could. I guess they just didn't look to see where the aircraft parked or had expectation bias because it said B737 on the data tag even though the ramp monitor said otherwise. Also; the ls guy said he asked the pilot if he had been called heavy his entire flight and he said yes. The ls guy said he thought the pilot may have called himself heavy when he checked in; but the expectation of the data tag; and the fact that we avoid landing heavies over there because it shuts off departures for a considerable amount of time probably all played into the expectation bias. I might recommend that pilots insist on being called heavy if a controller forgets to say it in the transmission. It could have consequences. I can only imagine these two departures less than 1500 feet apart; side by side getting caught in a vortex at night! Scary stuff. Not landing on 9 would be great too.

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Original NASA ASRS Text

Title: IAH Tower Controller reported a B767 was improperly coded as a B737 and thus proper wake procedures were not followed on the arrival.

Narrative: I was working Local West (LW) so I was working departures on 15R/L. We are on an East flow meaning landing from the west to the east. North departures were going to runway 9. We had been told that we would also have 3 arrivals to runway 9. The final for runway 9 crosses both 15L and 15R. The last arrival was a B737. I continued rolling departures in front of him until he got about 2 miles west of 15R. I may not have told all aircraft that traffic was landing the crossing runway when I Line Up and Waited them. I don't recall. Anyway; I put [an E170] on 15L and [the B737] on 15R and waited for the arrival to pass. As soon as he did pass; I cleared them for takeoff. It was night time already so seeing the type of aircraft out the window was impossible until about a 1/2 mile final or so. The airplane looked pretty big. I looked again at the display and the ASDE as well. All appeared normal. Something didn't look right though. The plane was huge! I said; 'what kind of plane is that?! It is not a 737.' I rolled no more departures until I was sure. The Local South (LS) guy asked the pilot and he said he was a 767; yes a heavy. So here I just rolled two departures under his wake. The supervisor in charge at the time began to track down what had happened. You remember a while back we had a issue with a mismarked aircraft travel across the country. Thank goodness this was just in Houston Approach Airspace. In the time I took between filing this report back on position the other supervisor (not the one in charge at the time of the issue) said that someone at I90 inadvertently deleted the type aircraft and then put him back in as a 737 instead of a 767. Several things could have clued us in that this aircraft was a heavy. One; the ramp monitor at Local South (LS) showed him as a heavy. I couldn't see it from where I was working; but the LS could. I guess they just didn't look to see where the aircraft parked or had expectation bias because it said B737 on the data tag even though the ramp monitor said otherwise. Also; the LS guy said he asked the pilot if he had been called heavy his entire flight and he said yes. The LS guy said he thought the pilot may have called himself heavy when he checked in; but the expectation of the data tag; and the fact that we avoid landing heavies over there because it shuts off departures for a considerable amount of time probably all played into the expectation bias. I might recommend that pilots insist on being called heavy if a controller forgets to say it in the transmission. It could have consequences. I can only imagine these two departures less than 1500 feet apart; side by side getting caught in a vortex at night! Scary stuff. Not landing on 9 would be great too.

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.