 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
ZLA controller experienced operational error at FL200 when misjudging the lateral distance between a climbing and descending aircraft.
| Attributes | |
| ACN | 718858 |
| Time | |
| Date | 200611 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : zla.artcc |
| State Reference | CA |
| Altitude | msl single value : 20000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zla.artcc tower : bec.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | departure : on vectors |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zla.artcc |
| Operator | general aviation : corporate |
| Make Model Name | Citation II S2/Bravo |
| Operating Under FAR Part | Part 91 |
| Flight Phase | descent : intermediate altitude |
| Route In Use | arrival : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar controller : non radar |
| Experience | controller military : 9 controller non radar : 2 controller radar : 5 controller time certified in position1 : 2 flight time total : 60 |
| ASRS Report | 718858 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation |
| Independent Detector | atc equipment : conflict alert other controllera |
| Resolutory Action | none taken : detected after the fact |
| Consequence | faa : investigated |
| Miss Distance | horizontal : 27000 vertical : 900 |
| Supplementary | |
| Problem Areas | ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
B737; a san departure; assigned FL200 for a C550 descending to FL210; a cma arrival. Mutual traffic was issued and both aircraft reported each other in sight. After aircraft diverged and it appeared that I had 5 mi or more of lateral separation; the B737 was assigned climb to FL230 and the C550 was assigned descent to 17000 ft. Conflict alert activated and a j-ring was put around the C550. I observed the B737's track to touch the outermost portion of the j-ring (5 mi bubble); looked at the flight history and then advised my supervisor that a possible loss of separation may have occurred. Solution: should have put the j-ring up around C550 prior to climbing the B737.
Original NASA ASRS Text
Title: ZLA CTLR EXPERIENCED OPERROR AT FL200 WHEN MISJUDGING THE LATERAL DISTANCE BTWN A CLBING AND DSNDING ACFT.
Narrative: B737; A SAN DEP; ASSIGNED FL200 FOR A C550 DSNDING TO FL210; A CMA ARR. MUTUAL TFC WAS ISSUED AND BOTH ACFT RPTED EACH OTHER IN SIGHT. AFTER ACFT DIVERGED AND IT APPEARED THAT I HAD 5 MI OR MORE OF LATERAL SEPARATION; THE B737 WAS ASSIGNED CLB TO FL230 AND THE C550 WAS ASSIGNED DSCNT TO 17000 FT. CONFLICT ALERT ACTIVATED AND A J-RING WAS PUT AROUND THE C550. I OBSERVED THE B737'S TRACK TO TOUCH THE OUTERMOST PORTION OF THE J-RING (5 MI BUBBLE); LOOKED AT THE FLT HISTORY AND THEN ADVISED MY SUPVR THAT A POSSIBLE LOSS OF SEPARATION MAY HAVE OCCURRED. SOLUTION: SHOULD HAVE PUT THE J-RING UP AROUND C550 PRIOR TO CLBING THE B737.
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.