Narrative:

I was providing radar advisories to aircraft X; a C172; within my delegated airspace at anc approach control. After 1 hour of air work; aircraft X requested practice ILS approachs at anc. After checking on the traffic flow at anc; aircraft X was subsequently issued a vector to the final approach course; an altitude to maintain; a transponder code change to allow for MSAW warnings; and climb out instructions. The instructions were broken up into manageable xmissions as to not overload the pilot in training. Aircraft X was then handed off to the arrival sector for sequencing into anc. During the time aircraft X was being provided service; maintenance was being allowed to proceed unchked at the anc approach control. The noise level of which was elevated to the point understanding xmissions and readbacks became laborious. Several times I pleaded with the operational supervisor to find the cause of the noise and to have it terminated. The noise was akin to an air jack-hammer being used to break up concrete below our working area. Later this was found out to be true. I even went so far as to broadcast on the building intercom system for the maintenance to cease and desist; to no avail. Just as mind boggling was the fact the anc ATC manager would even allow this type of distraction to proceed at all. The result of all the confusion and distraction in the approach control room led to aircraft X being issued an erroneous climb out heading. The normal heading would have been 'fly heading two-zero-zero' what I issued and could not believe until after the tapes were reviewed was 'fly heading zero-two-zero.' the aircraft even read back the twenty heading and I neither caught myself during the transmission nor during the readback. Aircraft X then turned nebound after departure and flew into adjacent class D airspace without authority/authorized. The only explanation I could come up with was the noise level being such a distraction I just missed it. Transmitting and hearing the two and zero in combination seemed to satisfy me even though they were transposed. I've issued this heading a thousand times and could not believe I issued it incorrectly.

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Original NASA ASRS Text

Title: A11 CTLR DESCRIBED OPDEV WHEN INCORRECT CLBOUT HDGS WERE ISSUED DURING NOISE DISTRS IN THE FACILITY.

Narrative: I WAS PROVIDING RADAR ADVISORIES TO ACFT X; A C172; WITHIN MY DELEGATED AIRSPACE AT ANC APCH CTL. AFTER 1 HR OF AIR WORK; ACFT X REQUESTED PRACTICE ILS APCHS AT ANC. AFTER CHKING ON THE TFC FLOW AT ANC; ACFT X WAS SUBSEQUENTLY ISSUED A VECTOR TO THE FINAL APCH COURSE; AN ALT TO MAINTAIN; A XPONDER CODE CHANGE TO ALLOW FOR MSAW WARNINGS; AND CLBOUT INSTRUCTIONS. THE INSTRUCTIONS WERE BROKEN UP INTO MANAGEABLE XMISSIONS AS TO NOT OVERLOAD THE PLT IN TRAINING. ACFT X WAS THEN HANDED OFF TO THE ARR SECTOR FOR SEQUENCING INTO ANC. DURING THE TIME ACFT X WAS BEING PROVIDED SVC; MAINT WAS BEING ALLOWED TO PROCEED UNCHKED AT THE ANC APCH CTL. THE NOISE LEVEL OF WHICH WAS ELEVATED TO THE POINT UNDERSTANDING XMISSIONS AND READBACKS BECAME LABORIOUS. SEVERAL TIMES I PLEADED WITH THE OPERATIONAL SUPVR TO FIND THE CAUSE OF THE NOISE AND TO HAVE IT TERMINATED. THE NOISE WAS AKIN TO AN AIR JACK-HAMMER BEING USED TO BREAK UP CONCRETE BELOW OUR WORKING AREA. LATER THIS WAS FOUND OUT TO BE TRUE. I EVEN WENT SO FAR AS TO BROADCAST ON THE BUILDING INTERCOM SYS FOR THE MAINT TO CEASE AND DESIST; TO NO AVAIL. JUST AS MIND BOGGLING WAS THE FACT THE ANC ATC MGR WOULD EVEN ALLOW THIS TYPE OF DISTR TO PROCEED AT ALL. THE RESULT OF ALL THE CONFUSION AND DISTR IN THE APCH CTL ROOM LED TO ACFT X BEING ISSUED AN ERRONEOUS CLBOUT HDG. THE NORMAL HDG WOULD HAVE BEEN 'FLY HDG TWO-ZERO-ZERO' WHAT I ISSUED AND COULD NOT BELIEVE UNTIL AFTER THE TAPES WERE REVIEWED WAS 'FLY HDG ZERO-TWO-ZERO.' THE ACFT EVEN READ BACK THE TWENTY HDG AND I NEITHER CAUGHT MYSELF DURING THE XMISSION NOR DURING THE READBACK. ACFT X THEN TURNED NEBOUND AFTER DEP AND FLEW INTO ADJACENT CLASS D AIRSPACE WITHOUT AUTH. THE ONLY EXPLANATION I COULD COME UP WITH WAS THE NOISE LEVEL BEING SUCH A DISTR I JUST MISSED IT. XMITTING AND HEARING THE TWO AND ZERO IN COMBINATION SEEMED TO SATISFY ME EVEN THOUGH THEY WERE TRANSPOSED. I'VE ISSUED THIS HDG A THOUSAND TIMES AND COULD NOT BELIEVE I ISSUED IT INCORRECTLY.

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.