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Foreign ARTCC coordinated new altitude for air carrier aircraft, which was approved by controller at ZHU. Later the air carrier aircraft had less than standard separation with a corp aircraft over a non radar fix. Air carrier aircraft saw the potential conflict on its TCASII, but not before separation was lost and aircraft saw each other.
| Attributes | |
| ACN | 264761 |
| Time | |
| Date | 199403 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : gls |
| State Reference | TX |
| Altitude | msl bound lower : 35000 msl bound upper : 35000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : fsd |
| Operator | common carrier : air carrier |
| Make Model Name | B727 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other |
| Route In Use | enroute : other oceanic enroute airway : zhu |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | general aviation : corporate |
| Make Model Name | Citation II S2/Bravo |
| Operating Under FAR Part | Part 91 |
| Flight Phase | cruise other |
| Route In Use | enroute : other oceanic |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Experience | controller non radar : 8 controller radar : 7 |
| ASRS Report | 264761 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : flight data |
| Qualification | controller : radar |
| Experience | controller non radar : 2 controller radar : 1 |
| ASRS Report | 265214 |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation non adherence : published procedure |
| Independent Detector | other flight crewa |
| Resolutory Action | none taken : detected after the fact |
| Consequence | faa : investigated |
| Miss Distance | horizontal : 30000 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error Inter Facility Coordination Failure Intra Facility Coordination Failure |
Narrative:
We were working the sector over the gulf of mexico (non radar). Merida center passed a flight plan to our sector at FL310. Shortly thereafter, merida center called back to revise the aircraft's altitude to FL350. The controller working the d- side approved the altitude change, but did not follow through with marking the other strips on the aircraft (nwbound). We had a swbound aircraft at FL350 which was crossing with the nwbound aircraft at FL350, which we were showing an altitude of FL310 where they crossed. We didn't know of a problem until the nwbound aircraft reported an aircraft on his TCASII at his 3 O'clock. The nwbound aircraft was advised that the swbound aircraft was a citation at FL350. The pilot responded, FL350? He was told affirmative and asked his assigned altitude. He replied FL350, which we were showing FL310. I could not climb or descend either aircraft because of traffic at FL330 and FL370 in the vicinity (all non radar). The swbound aircraft was advised of the traffic and responded, 'traffic in sight.' the nwbound aircraft reported that he had an altitude resolution alert from his TCASII. Supplemental information from acn 265214: a B727 and C550 crossed at FL350 non radar with less than 15 mins ICAO separation. The B727 was originally at FL310. Merida center passed the revised altitude of FL350 and the first d-side approved it. #1 d-side wrote FL350 on the first strip but not on the second or third. That controller also neglected to enter the altitude in the computer. The second d-side relieved the first d-side and did not see the strip marking errors. The second d-side then relieved the r-side and combined both position to the r-side. 30 mins later, the second r-side was relieved. Right after briefing the B727 checked on at FL350. This was rogered but not caught by r-side #3. 8 mins later the B727 asked who was his traffic at FL350 and 3 O'clock. Before the B727 entered ZHU airspace a departure off of new was climbed to FL350 because his requested altitude of FL310 was already taken by the B727 as reflected by the B727's second strip. The second d-side approved FL350 on the C550 after assuming the r-side position. If the B727 had reported the fir in accordance with FARS and ICAO rules, this error would have been caught and resolved before loss of separation occurred.
Original NASA ASRS Text
Title: FOREIGN ARTCC COORDINATED NEW ALT FOR ACR ACFT, WHICH WAS APPROVED BY CTLR AT ZHU. LATER THE ACR ACFT HAD LTSS WITH A CORP ACFT OVER A NON RADAR FIX. ACR ACFT SAW THE POTENTIAL CONFLICT ON ITS TCASII, BUT NOT BEFORE SEPARATION WAS LOST AND ACFT SAW EACH OTHER.
Narrative: WE WERE WORKING THE SECTOR OVER THE GULF OF MEXICO (NON RADAR). MERIDA CTR PASSED A FLT PLAN TO OUR SECTOR AT FL310. SHORTLY THEREAFTER, MERIDA CTR CALLED BACK TO REVISE THE ACFT'S ALT TO FL350. THE CTLR WORKING THE D- SIDE APPROVED THE ALT CHANGE, BUT DID NOT FOLLOW THROUGH WITH MARKING THE OTHER STRIPS ON THE ACFT (NWBOUND). WE HAD A SWBOUND ACFT AT FL350 WHICH WAS XING WITH THE NWBOUND ACFT AT FL350, WHICH WE WERE SHOWING AN ALT OF FL310 WHERE THEY CROSSED. WE DIDN'T KNOW OF A PROB UNTIL THE NWBOUND ACFT RPTED AN ACFT ON HIS TCASII AT HIS 3 O'CLOCK. THE NWBOUND ACFT WAS ADVISED THAT THE SWBOUND ACFT WAS A CITATION AT FL350. THE PLT RESPONDED, FL350? HE WAS TOLD AFFIRMATIVE AND ASKED HIS ASSIGNED ALT. HE REPLIED FL350, WHICH WE WERE SHOWING FL310. I COULD NOT CLB OR DSND EITHER ACFT BECAUSE OF TFC AT FL330 AND FL370 IN THE VICINITY (ALL NON RADAR). THE SWBOUND ACFT WAS ADVISED OF THE TFC AND RESPONDED, 'TFC IN SIGHT.' THE NWBOUND ACFT RPTED THAT HE HAD AN ALT RESOLUTION ALERT FROM HIS TCASII. SUPPLEMENTAL INFO FROM ACN 265214: A B727 AND C550 CROSSED AT FL350 NON RADAR WITH LESS THAN 15 MINS ICAO SEPARATION. THE B727 WAS ORIGINALLY AT FL310. MERIDA CTR PASSED THE REVISED ALT OF FL350 AND THE FIRST D-SIDE APPROVED IT. #1 D-SIDE WROTE FL350 ON THE FIRST STRIP BUT NOT ON THE SECOND OR THIRD. THAT CTLR ALSO NEGLECTED TO ENTER THE ALT IN THE COMPUTER. THE SECOND D-SIDE RELIEVED THE FIRST D-SIDE AND DID NOT SEE THE STRIP MARKING ERRORS. THE SECOND D-SIDE THEN RELIEVED THE R-SIDE AND COMBINED BOTH POS TO THE R-SIDE. 30 MINS LATER, THE SECOND R-SIDE WAS RELIEVED. RIGHT AFTER BRIEFING THE B727 CHKED ON AT FL350. THIS WAS ROGERED BUT NOT CAUGHT BY R-SIDE #3. 8 MINS LATER THE B727 ASKED WHO WAS HIS TFC AT FL350 AND 3 O'CLOCK. BEFORE THE B727 ENTERED ZHU AIRSPACE A DEP OFF OF NEW WAS CLBED TO FL350 BECAUSE HIS REQUESTED ALT OF FL310 WAS ALREADY TAKEN BY THE B727 AS REFLECTED BY THE B727'S SECOND STRIP. THE SECOND D-SIDE APPROVED FL350 ON THE C550 AFTER ASSUMING THE R-SIDE POS. IF THE B727 HAD RPTED THE FIR IN ACCORDANCE WITH FARS AND ICAO RULES, THIS ERROR WOULD HAVE BEEN CAUGHT AND RESOLVED BEFORE LOSS OF SEPARATION OCCURRED.
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.