Air Traffic Control Fully Certified
Situational Awareness; Communication Breakdown
ATC Issue All Types; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Human Factors
My Manual Controller pointed out a Citation XL to the BAE Sector descending to FL330 as per the SOP for DTW traffic. The BAE Controller accepted the point-out reference MD90. My Manual Controller advised me of the traffic which I observed. I knew I wanted to start Citation XL down to FL350 so that we could later give him the standard crossing restriction of FL330. This was a simple case of seeing the traffic at FL330 and issuing the assigned altitude FL330; not FL350 like I wanted to. When I saw Citation XL descending through what I thought the assigned altitude of FL350 I had the aircraft maintain his present altitude (FL347). It was too late the aircraft was already through FL340 so I climbed him back up to FL340. When I later listened to the pilot read back; I realized what I had done. Occasionally a controller will do what I did; observe the aircraft's altitude that they are supposed to miss and still issue the very same altitude.
A Citation XL was on route to DTW at FL390 the HOR Sector is required to descend DTW arrivals to FL330. I was working the D-Side and pointed the Citation XL out to Sector 60 who showed me the traffic (a MD90) I than told my RADAR Controller about the traffic and moved on to work on other things The RADAR Controller thought he cleared the Citation XL to FL350 but noticed him descend through the altitude and tried to stop his descent but was not able to stop the aircraft in time. I feel this is one of those human errors you look at the aircraft at FL330; think you are saying FL350 but FL330 is issued.
ZAU Controller described a conflict vent when thinking one altitude but issuing a conflicting altitude assignment.