Narrative:

ZFW called to coordinate aircraft X on a 310 heading and level at 4000. I did have [air carrier] arrival traffic and two other arrivals; ongoing to ftw and the other going to afw. The data tag was not correlating with the target for aircraft X so to take radar contact I called the ZFW sector back for position and altitude. I was told again heading 310 for dodge intersection and I confirmed level at 4000. When aircraft X checked on he reported on the heading and level at 6000; which I did not hear 6000 because I was thinking he was level at 4000. Aircraft Y was the arrival after aircraft X both of these aircraft are flying along the same airway to get to the west side of our airspace. I descended aircraft Y to 6000; above aircraft X still thinking he was level at 4000. I did have aircraft X try to recycle his transponder on initial call to see if that would help acquire the data tag of target and it did not help. I even put an additional reminder of his altitude; 4000; on his data block so I would know and so the receiving controller would know that was their altitude. When aircraft X finally did start to acquire with the target I saw an altitude of 6000. I then asked him what his altitude was and he replied 6000. I immediately called the supervisor over and let him know. I called ZFW to confirm with them that he was supposed to be at level at 4000. This was an event because I failed to hear on the initial call that he said he was at 6000. Even though controllers are coordinating and telling you the information that you 'need' to know. We still need to listen carefully and ensure that the aircraft checking in with us are confirming the information that we are given through coordination.

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Original NASA ASRS Text

Title: D10 Controller reports of an aircraft that is having problems with the altitude portion of the Mode-C that is being displayed on his scope. The Controller thinks he issues the aircraft 4;000 which it is supposed to be at but aircraft is level at 6;000. Another aircraft is level at 6;000; the Controller thinks they are separated but they are at the same altitude.

Narrative: ZFW called to coordinate Aircraft X on a 310 heading and level at 4000. I did have [air carrier] arrival traffic and two other arrivals; ongoing to FTW and the other going to AFW. The data tag was not correlating with the target for Aircraft X so to take radar contact I called the ZFW sector back for position and altitude. I was told again heading 310 for Dodge intersection and I confirmed level at 4000. When Aircraft X checked on he reported on the heading and level at 6000; which I did not hear 6000 because I was thinking he was level at 4000. Aircraft Y was the arrival after Aircraft X both of these aircraft are flying along the same airway to get to the west side of our airspace. I descended Aircraft Y to 6000; above Aircraft X still thinking he was level at 4000. I did have Aircraft X try to recycle his transponder on initial call to see if that would help acquire the data tag of target and it did not help. I even put an additional reminder of his altitude; 4000; on his data block so I would know and so the receiving controller would know that was their altitude. When Aircraft X finally did start to acquire with the target I saw an altitude of 6000. I then asked him what his altitude was and he replied 6000. I immediately called the supervisor over and let him know. I called ZFW to confirm with them that he was supposed to be at level at 4000. This was an event because I failed to hear on the initial call that he said he was at 6000. Even though controllers are coordinating and telling you the information that you 'Need' to know. We still need to listen carefully and ensure that the aircraft checking in with us are confirming the information that we are given through coordination.

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.