|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||atc facility : gsp|
|Altitude||msl bound lower : 17000|
msl bound upper : 18000
|Controlling Facilities||artcc : ztl|
|Operator||common carrier : air carrier|
|Make Model Name||Medium Large Transport, Low Wing, 2 Turbojet Eng|
|Flight Phase||cruise other|
|Route In Use||enroute airway : ztl|
|Operator||general aviation : corporate|
|Make Model Name||Small Transport, Low Wing, 2 Turboprop Eng|
|Flight Phase||climbout : intermediate altitude|
|Affiliation||government : faa|
|Function||controller : flight data|
|Qualification||controller : non radar|
|Function||controller : radar|
|Qualification||controller : radar|
|Anomaly||non adherence : published procedure|
|Independent Detector||other controllera|
|Resolutory Action||none taken : anomaly accepted|
|Primary Problem||ATC Human Performance|
|Air Traffic Incident||Operational Deviation|
I was working D-28 (manual controller) in atl center small transport Y was sbound over spa VORTAC climbing medium large transport X was wbound into atl at FL180. The medium large transport X was level at FL180 the small transport Y climbing sbound. The radar controller issued 17000' to the small transport Y. A sector note showed FL180 out of service due to low altimeter. The right 28 controller gave 17000 to the small transport Y with local altimeter being 29.83 at gsp. I observed this and asked right side to check the gsp altimeter. At which time she did noticed it was low and did nothing, as the 2 aircraft passed overhead, and targets merged. Both mode C showed level, and pilots reported each other in sight. No conflict alert or switch was activated. I am not 100% sure on call signs, but time is right. There should be some way on scope to show when FL180 is out of service!!!
Original NASA ASRS Text
Title: ARTCC RADAR CTLR USED FL180 WHEN LOCAL ALTIMETER WAS BELOW 29 PT 92. MLG AND SMT PASSED WITH 1000' SEPARATION AND NO CONFLICT ALERT ACTIVATED.
Narrative: I WAS WORKING D-28 (MANUAL CTLR) IN ATL CENTER SMT Y WAS SBOUND OVER SPA VORTAC CLIMBING MLG X WAS WBOUND INTO ATL AT FL180. THE MLG X WAS LEVEL AT FL180 THE SMT Y CLIMBING SBOUND. THE RADAR CTLR ISSUED 17000' TO THE SMT Y. A SECTOR NOTE SHOWED FL180 OUT OF SERVICE DUE TO LOW ALTIMETER. THE R 28 CTLR GAVE 17000 TO THE SMT Y WITH LOCAL ALTIMETER BEING 29.83 AT GSP. I OBSERVED THIS AND ASKED R SIDE TO CHECK THE GSP ALTIMETER. AT WHICH TIME SHE DID NOTICED IT WAS LOW AND DID NOTHING, AS THE 2 ACFT PASSED OVERHEAD, AND TARGETS MERGED. BOTH MODE C SHOWED LEVEL, AND PLTS REPORTED EACH OTHER IN SIGHT. NO CONFLICT ALERT OR SWITCH WAS ACTIVATED. I AM NOT 100% SURE ON CALL SIGNS, BUT TIME IS RIGHT. THERE SHOULD BE SOME WAY ON SCOPE TO SHOW WHEN FL180 IS OUT OF SERVICE!!!
Data retrieved from NASA's ASRS site as of August 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.