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ZTL controller experienced operational error at FL320 when incorrect altitude readback was missed and aircraft ascended into occupied altitude.
| Attributes | |
| ACN | 677681 |
| Time | |
| Date | 200511 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | navaid : emi.vortac |
| State Reference | MD |
| Altitude | msl single value : 32000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : ztl.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B767-300 and 300 ER |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : ztl.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | EMB ERJ 170/175 ER&LR |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : initial |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Experience | controller radar : 23 |
| ASRS Report | 677681 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Events | |
| Anomaly | non adherence : required legal separation |
| Independent Detector | atc equipment : conflict alert other controllera |
| Resolutory Action | controller : issued alert controller : issued new clearance |
| Consequence | faa : investigated |
| Miss Distance | horizontal : 18000 vertical : 500 |
| Supplementary | |
| Problem Areas | ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
I was working potomac high altitude radar position. I took 2 handoffs from ZNY: air carrier X at FL320; and air carrier Y climbing to FL300. ZNY issued a climb to FL300 to air carrier Y. Air carrier Y read back FL330; but he ZNY controller missed the improper readback. Both aircraft were handed off to me at ZDC; and change of communication was issued. Air carrier X checked on at FL320. Air carrier Y checked on 1 min later; out of FL270 for FL330. Because I was busy with 2 other traffic situations; I looked at air carrier Y; saw his data block at FL300 and 'rogered' him (missing the fact that he was actually climbing to FL330). When conflict alert activated (air carrier Y showing FL305); I immediately thought that it was a mode C swap. Radar coverage is so bad in this area; that we have several mode C supervisors; and target jumps every hour. On the next radar hit; I noticed that air carrier Y was still climbing. I immediately stopped his climb and issued a descent; but standard separation was lost.
Original NASA ASRS Text
Title: ZTL CTLR EXPERIENCED OPERROR AT FL320 WHEN INCORRECT ALT READBACK WAS MISSED AND ACFT ASCENDED INTO OCCUPIED ALT.
Narrative: I WAS WORKING POTOMAC HIGH ALT RADAR POS. I TOOK 2 HDOFS FROM ZNY: ACR X AT FL320; AND ACR Y CLBING TO FL300. ZNY ISSUED A CLB TO FL300 TO ACR Y. ACR Y READ BACK FL330; BUT HE ZNY CTLR MISSED THE IMPROPER READBACK. BOTH ACFT WERE HANDED OFF TO ME AT ZDC; AND CHANGE OF COM WAS ISSUED. ACR X CHKED ON AT FL320. ACR Y CHKED ON 1 MIN LATER; OUT OF FL270 FOR FL330. BECAUSE I WAS BUSY WITH 2 OTHER TFC SITUATIONS; I LOOKED AT ACR Y; SAW HIS DATA BLOCK AT FL300 AND 'ROGERED' HIM (MISSING THE FACT THAT HE WAS ACTUALLY CLBING TO FL330). WHEN CONFLICT ALERT ACTIVATED (ACR Y SHOWING FL305); I IMMEDIATELY THOUGHT THAT IT WAS A MODE C SWAP. RADAR COVERAGE IS SO BAD IN THIS AREA; THAT WE HAVE SEVERAL MODE C SUPVRS; AND TARGET JUMPS EVERY HR. ON THE NEXT RADAR HIT; I NOTICED THAT ACR Y WAS STILL CLBING. I IMMEDIATELY STOPPED HIS CLB AND ISSUED A DSCNT; BUT STANDARD SEPARATION WAS LOST.
Data retrieved from NASA's ASRS site as of January 2009 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.