Narrative:

I was radar controller on sampson sector (R26) at washington ARTCC at time of occurrence. One fgt X was in a holding pattern at clubb intersection at 11,000 MSL and already switched to gsb approach. I issued clearance to another fgt Y to descend and maintain 12,000 MSL and to expect holding at clubb intersection. Fgt Y answered 'roger, 1-2 thousand.' I was busy sequencing air carrier (airline name) arrivals into rdu. I was advised by the controller beside me that fgt Y had busted his altitude clearance. I looked and he was at 11,000 and rapidly overrunning fgt X who was also still at 11,000. I immediately climbed fgt Y back up to 12,000 and informed him that his altitude clearance was 12,000'. He made no comment other than 'roger'. All this was borne out by replay of ATC tapes. Two factors I think contributed to this. One is the relatively low time of military pilots in training at gsb in the fgt's. I have the highest respect for the military training of its pilots but many of the pilots have relatively low time to be flying such complex aircraft. Another problem that I think contributed to not noticing fgt Y's descent sooner was lack of flow control on the air carrier (name) flts at that time. Jacksonville center's flow control officers are supposed to control the departures of air carrier (name) off of myr, cae, chs which pop off right underneath the already airborne flow that is headed for rdu over ilm, ILM012.BRADE2.rdu. Jax flow controllers have been unable or unwilling to do the job they are supposed to do in this respect and it creates a chaotic and I fell hazardous situation at sampson sector (R26) in washington center when you have to issue extensive vectors to numerous air carrier (name) to get required intrail spacing to rdu approach. If I had not been so busy with this (daily) aerial circus of air carrier (name), I might have noticed fgt Y's descent in time to prevent the loss of separation between him and fgt X. Since the loss of separation was attributed to pilot deviation and not my error, this is not an effort protect myself but a genuine desire to see what I feel is an unsafe condition brought to light and corrected.

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Original NASA ASRS Text

Title: FGT DESCENDED BELOW ASSIGNED ALT RESULTING IN LESS THAN STANDARD SEPARATION.

Narrative: I WAS RADAR CTLR ON SAMPSON SECTOR (R26) AT WASHINGTON ARTCC AT TIME OF OCCURRENCE. ONE FGT X WAS IN A HOLDING PATTERN AT CLUBB INTXN AT 11,000 MSL AND ALREADY SWITCHED TO GSB APCH. I ISSUED CLRNC TO ANOTHER FGT Y TO DSND AND MAINTAIN 12,000 MSL AND TO EXPECT HOLDING AT CLUBB INTXN. FGT Y ANSWERED 'ROGER, 1-2 THOUSAND.' I WAS BUSY SEQUENCING ACR (AIRLINE NAME) ARRIVALS INTO RDU. I WAS ADVISED BY THE CTLR BESIDE ME THAT FGT Y HAD BUSTED HIS ALT CLRNC. I LOOKED AND HE WAS AT 11,000 AND RAPIDLY OVERRUNNING FGT X WHO WAS ALSO STILL AT 11,000. I IMMEDIATELY CLIMBED FGT Y BACK UP TO 12,000 AND INFORMED HIM THAT HIS ALT CLRNC WAS 12,000'. HE MADE NO COMMENT OTHER THAN 'ROGER'. ALL THIS WAS BORNE OUT BY REPLAY OF ATC TAPES. TWO FACTORS I THINK CONTRIBUTED TO THIS. ONE IS THE RELATIVELY LOW TIME OF MIL PLTS IN TRAINING AT GSB IN THE FGT'S. I HAVE THE HIGHEST RESPECT FOR THE MIL TRAINING OF ITS PLTS BUT MANY OF THE PLTS HAVE RELATIVELY LOW TIME TO BE FLYING SUCH COMPLEX ACFT. ANOTHER PROBLEM THAT I THINK CONTRIBUTED TO NOT NOTICING FGT Y'S DSCNT SOONER WAS LACK OF FLOW CTL ON THE ACR (NAME) FLTS AT THAT TIME. JACKSONVILLE CENTER'S FLOW CTL OFFICERS ARE SUPPOSED TO CONTROL THE DEPS OF ACR (NAME) OFF OF MYR, CAE, CHS WHICH POP OFF RIGHT UNDERNEATH THE ALREADY AIRBORNE FLOW THAT IS HEADED FOR RDU OVER ILM, ILM012.BRADE2.RDU. JAX FLOW CTLRS HAVE BEEN UNABLE OR UNWILLING TO DO THE JOB THEY ARE SUPPOSED TO DO IN THIS RESPECT AND IT CREATES A CHAOTIC AND I FELL HAZARDOUS SITUATION AT SAMPSON SECTOR (R26) IN WASHINGTON CENTER WHEN YOU HAVE TO ISSUE EXTENSIVE VECTORS TO NUMEROUS ACR (NAME) TO GET REQUIRED INTRAIL SPACING TO RDU APCH. IF I HAD NOT BEEN SO BUSY WITH THIS (DAILY) AERIAL CIRCUS OF ACR (NAME), I MIGHT HAVE NOTICED FGT Y'S DSCNT IN TIME TO PREVENT THE LOSS OF SEPARATION BETWEEN HIM AND FGT X. SINCE THE LOSS OF SEPARATION WAS ATTRIBUTED TO PLT DEVIATION AND NOT MY ERROR, THIS IS NOT AN EFFORT PROTECT MYSELF BUT A GENUINE DESIRE TO SEE WHAT I FEEL IS AN UNSAFE CONDITION BROUGHT TO LIGHT AND CORRECTED.

Data retrieved from NASA's ASRS site as of August 2007 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.