37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Attributes | |
ACN | 526809 |
Time | |
Date | 200110 |
Day | Wed |
Local Time Of Day | 1801 To 2400 |
Place | |
Locale Reference | intersection : weirs |
State Reference | TX |
Altitude | msl bound lower : 29000 msl bound upper : 31000 |
Environment | |
Flight Conditions | IMC |
Weather Elements | Thunderstorm |
Light | Night |
Aircraft 1 | |
Controlling Facilities | artcc : zfw.artcc tracon : hnl.tracon |
Operator | common carrier : air carrier |
Make Model Name | A319 |
Operating Under FAR Part | Part 121 |
Flight Phase | descent : holding |
Flight Plan | IFR |
Aircraft 2 | |
Controlling Facilities | artcc : zfw.artcc |
Operator | common carrier : air carrier |
Make Model Name | B757-200 |
Operating Under FAR Part | Part 121 |
Flight Phase | descent : holding |
Flight Plan | IFR |
Person 1 | |
Affiliation | government : faa |
Function | controller : radar |
Qualification | controller : radar |
ASRS Report | 526809 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Events | |
Anomaly | conflict : airborne less severe non adherence : published procedure non adherence : required legal separation |
Independent Detector | atc equipment : conflict alert |
Resolutory Action | none taken : detected after the fact |
Consequence | faa : investigated |
Miss Distance | horizontal : 16200 vertical : 1600 |
Supplementary | |
Problem Areas | ATC Human Performance Airspace Structure Environmental Factor Weather |
Primary Problem | ATC Human Performance |
Air Traffic Incident | Inter Facility Coordination Failure Intra Facility Coordination Failure Operational Error |
Situations | |
ATC Facility | staffing : zfw.artcc |
Narrative:
WX (thunderstorms) covered the northwest portion of ft worth center airspace and additional WX was just ese of ZFW airspace in houston and memphis center airspace, creating a corridor of clear airspace that ran from the northeast to the southwest. Of the 6040 aircraft that transitioned through ft worth center, approximately 3500 passed through cqy airspace with no additional staffing to assist. I took over fzt-H sector just as dfw approach shut off all arrivals due to thunderstorms at XA40 local time. Three aircraft had already passed the holding fixes and had to be brought back to the weirs intersection. From XA40 until XC15, when I was relieved from position, there were 14-16 aircraft holding at the Z holding fixes in fzt-H sector, and a similar number holding in the low altitude sector below. Both dfw and dal airports were closed from XA40 to XB50, yet houston terminal departures en route to the airports continued to depart and enter fzt-H at FL240, FL260 and FL280. Through vectoring until the altitude was available, these aircraft were blended into the stack. Aircraft X at FL310 and aircraft Y at FL330 arrived from the east. Aircraft X continued past weirs to the northwest, and was turned left to proceed back to weirs when aircraft X was 15 miles north of weirs. Aircraft Y made the turn in the holding pattern and was descended to FL290 to get below aircraft X before he arrived in holding due to lack of adequate breaks and a constant inundation of traffic for 6 hours, straight, I missed that aircraft Y didn't immediately start his descent. I was busy trying to get 3 aircraft down from FL260, FL270 and FL280 to FL250, FL260 and FL270 so that a houston departure on vectors could be fit into the stack at his current altitude of FL280. Separation was lost 3 mins after descent clearance was given to aircraft Y.
Original NASA ASRS Text
Title: ZFW INVOLVED IN OPERROR BTWN AN A319 AND A B752 DURING ADVERSE WX FACTORS AND SIGNIFICANT HOLDING, WHILE ATTEMPTING TO THREAD ACFT DOWN THROUGH A HOLDING STACK.
Narrative: WX (THUNDERSTORMS) COVERED THE NW PORTION OF FT WORTH CENTER AIRSPACE AND ADDITIONAL WX WAS JUST ESE OF ZFW AIRSPACE IN HOUSTON AND MEMPHIS CENTER AIRSPACE, CREATING A CORRIDOR OF CLR AIRSPACE THAT RAN FROM THE NE TO THE SW. OF THE 6040 ACFT THAT TRANSITIONED THROUGH FT WORTH CENTER, APPROX 3500 PASSED THROUGH CQY AIRSPACE WITH NO ADDITIONAL STAFFING TO ASSIST. I TOOK OVER FZT-H SECTOR JUST AS DFW APCH SHUT OFF ALL ARRIVALS DUE TO THUNDERSTORMS AT XA40 LOCAL TIME. THREE ACFT HAD ALREADY PASSED THE HOLDING FIXES AND HAD TO BE BROUGHT BACK TO THE WEIRS INTXN. FROM XA40 UNTIL XC15, WHEN I WAS RELIEVED FROM POSITION, THERE WERE 14-16 ACFT HOLDING AT THE Z HOLDING FIXES IN FZT-H SECTOR, AND A SIMILAR NUMBER HOLDING IN THE LOW ALTITUDE SECTOR BELOW. BOTH DFW AND DAL ARPTS WERE CLOSED FROM XA40 TO XB50, YET HOUSTON TERMINAL DEPARTURES ENRTE TO THE ARPTS CONTINUED TO DEPART AND ENTER FZT-H AT FL240, FL260 AND FL280. THROUGH VECTORING UNTIL THE ALTITUDE WAS AVAILABLE, THESE ACFT WERE BLENDED INTO THE STACK. ACFT X AT FL310 AND ACFT Y AT FL330 ARRIVED FROM THE E. ACFT X CONTINUED PAST WEIRS TO THE NW, AND WAS TURNED LEFT TO PROCEED BACK TO WEIRS WHEN ACFT X WAS 15 MILES N OF WEIRS. ACFT Y MADE THE TURN IN THE HOLDING PATTERN AND WAS DSNDED TO FL290 TO GET BELOW ACFT X BEFORE HE ARRIVED IN HOLDING DUE TO LACK OF ADEQUATE BREAKS AND A CONSTANT INUNDATION OF TFC FOR 6 HRS, STRAIGHT, I MISSED THAT ACFT Y DIDN'T IMMEDIATELY START HIS DSCNT. I WAS BUSY TRYING TO GET 3 ACFT DOWN FROM FL260, FL270 AND FL280 TO FL250, FL260 AND FL270 SO THAT A HOUSTON DEPARTURE ON VECTORS COULD BE FIT INTO THE STACK AT HIS CURRENT ALTITUDE OF FL280. SEPARATION WAS LOST 3 MINS AFTER DSCNT CLRNC WAS GIVEN TO ACFT Y.
Data retrieved from NASA's ASRS site as of July 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.