 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Air carrier Y descent through occupied altitude had less than standard separation from air carrier Y. System error.
| Attributes | |
| ACN | 267288 |
| Time | |
| Date | 199403 |
| Day | Fri |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : bza |
| State Reference | AZ |
| Altitude | msl bound lower : 28000 msl bound upper : 29000 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zab artcc : zla tracon : ont |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other |
| Flight Phase | cruise other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other |
| Flight Phase | descent other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : developmental controller : radar |
| Experience | controller non radar : 1 controller radar : 2 |
| ASRS Report | 267288 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation non adherence : published procedure |
| Independent Detector | atc equipment other atc equipment : unspecified other controllera |
| Resolutory Action | controller : issued new clearance other |
| Consequence | faa : investigated |
| Miss Distance | horizontal : 17220 vertical : 7500 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Air carrier X was wbound at FL280 on a radar vector of 250 until receiving imperial. Aircraft had been handed off and communications transferred to ZLA. About 2 mins later, ZLA handed off air carrier Y at FL290 landing at phx. By LOA with ZLA, ZAB has control for descent to FL240 on contact with phx landers. When aircraft checked on frequency I descended him pilot's discretion to FL240 and handed the aircraft off and switched communications to the low sector. About a min later I realized the confliction which was still in ZLA's airspace and tried to stop Y from descending, but Y had already descended. Closest proximity was 2.87 NM lateral and 500 ft vertical.
Original NASA ASRS Text
Title: ACR Y DSCNT THROUGH OCCUPIED ALT HAD LTSS FROM ACR Y. SYS ERROR.
Narrative: ACR X WAS WBOUND AT FL280 ON A RADAR VECTOR OF 250 UNTIL RECEIVING IMPERIAL. ACFT HAD BEEN HANDED OFF AND COMS TRANSFERRED TO ZLA. ABOUT 2 MINS LATER, ZLA HANDED OFF ACR Y AT FL290 LNDG AT PHX. BY LOA WITH ZLA, ZAB HAS CTL FOR DSCNT TO FL240 ON CONTACT WITH PHX LANDERS. WHEN ACFT CHKED ON FREQ I DSNDED HIM PLT'S DISCRETION TO FL240 AND HANDED THE ACFT OFF AND SWITCHED COMS TO THE LOW SECTOR. ABOUT A MIN LATER I REALIZED THE CONFLICTION WHICH WAS STILL IN ZLA'S AIRSPACE AND TRIED TO STOP Y FROM DSNDING, BUT Y HAD ALREADY DSNDED. CLOSEST PROX WAS 2.87 NM LATERAL AND 500 FT VERT.
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.