ZDC CTLR EXPERIENCED OPERROR AT FL330 WHEN ACFT WAS ASSIGNED AN INCORRECT ALT AND THE ERROR WAS NOT DISCOVERED OR RELAYED.
Synopsis
ZDC CTLR EXPERIENCED OPERROR AT FL330 WHEN ACFT WAS ASSIGNED AN INCORRECT ALT AND THE ERROR WAS NOT DISCOVERED OR RELAYED.
Narrative
UPON ARR AT ZDC; AREA 8; I WAS INSTRUCTED TO RELIEVE THE CTLR (RADAR) AT SECTOR 58 (COYLE HI). AT THE TIME IT WAS BELIEVED THAT A POSSIBLE SYS ERROR HAD OCCURRED AND THE CTLR HAD TO BE RELIEVED FOR AN INVESTIGATION. THE AIR TFC AT THIS TIME WAS BUSY (12-15 ACFT) AND COMPLEX. DUE TO THE NEED TO STAFF THE 'GUARD DOG' SECTOR; THERE WERE NO ADDITIONAL STAFF AVAILABLE TO PROVIDE ASSISTANCE (RADAR ASSOCIATE) AT THE COYLE HI SECTOR. AFTER RECEIVING A BRIEFING I ASSUMED CTL OF THE SECTOR. NORMALLY; A CTLR WOULD NOT BE REMOVED DURING SUCH A BUSY PERIOD; BUT SINCE AN ERROR MAY HAVE OCCURRED THE CTLR NEEDED REMOVAL. AS SOON AS I TOOK CTL OF THE SECTOR I ISSUED SEVERAL CLRNCS TO ENSURE SEPARATION. I CLRED ACFT #1 TO FL310 AND ISSUED A SPD RESTR. ACFT #1 DID NOT RESPOND. I CONTINUED TO ISSUE OTHER NECESSARY CLRNCS. I REPEATED THE CLRNC TO ACFT #1; BUT MISSTATED THE ASSIGNED ALT AS FL350. THE ACFT RESPONDED TO THE CLB CLRNC AND WAS SWITCHED TO THE RECEIVING SECTOR. ACFT #1 RPTED INTO THE NEXT SECTOR STATING 'ACFT X THROUGH FL310.' THE ACFT DID NOT RPT ON WITH ITS ASSIGNED ALT. THE ACFT CLBED ABOVE WHAT THE RECEIVING CTLR BELIEVED WAS ITS ASSIGNED ALT AND LOST STANDARD SEPARATION WITH AN ACFT (B737) ABOVE IT. NOTE: GUARD DOG IS AN AIR DEFENSE SECTOR WHICH PROVIDES INFO FOR FIGHTER ACFT OVER THE CAPITOL. THERE HAS BEEN NO ADDITIONAL STAFFING ALLOCATED TO PROVIDE THIS SVC. BELIEVED I HAD CLRED ACFT TO AN ALT THAT WAS AVAILABLE. FACTORS AFFECTING PERFORMANCE: FIRST MIN OF FIRST SHIFT OF THE WK. THE BUZZ IN THE AREA ABOUT THE POSSIBLE FIRST ERROR. THE NEED TO TAKE OVER A BUSY SECTOR SOONER THAN WHAT WAS PRUDENT. THE DISTR CAUSED BY CTLRS REVIEWING THE EVENTS OF THE FIRST ERROR. THE RECEIVING CTLR'S INABILITY TO PROVIDE EXTRAORDINARY CLRNCS TO KEEP ALL THE ACFT SEPARATED DUE TO THEIR HIGH WORKLOAD. I DID NOT CORRECT ALT ASSIGNMENT WHEN IT WAS CLRLY READ BACK BY PLT. THE NEXT SECTOR FAILED TO NOTICE THE INCORRECT ALT DUE TO OMISSION OF ASSIGNED ALT BY PLT WHEN INITIAL COM WAS ESTABLISHED. THE 'CONFLICT ALERT' ALERTED THE RECEIVING CTLR THAT ACFT #1 HAD CLBED ABOVE ITS ASSIGNED ALT.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.