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ZID controller described near separation loss at FL290 when intrafac coordination failed and far too many assumptions were made by all involved.
| Attributes | |
| ACN | 741340 |
| Time | |
| Date | 200706 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | navaid : mie.vor |
| State Reference | IN |
| Altitude | msl single value : 29000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zid.artcc |
| Make Model Name | EMB ERJ 135 ER&LR |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zid.artcc |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Experience | controller time certified in position2 : 8 flight time total : 450 |
| ASRS Report | 741340 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | conflict : airborne less severe |
| Independent Detector | atc equipment : conflict alert other controllera |
| Resolutory Action | controller : issued alert controller : issued new clearance |
| Miss Distance | vertical : 1600 |
| Supplementary | |
| Problem Areas | ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Intra Facility Coordination Failure |
Narrative:
Sector 88 flashed a handoff on X climbing to FL300. They had switched aircraft to sector 89 and then they realized they had traffic. Called sector 89 to have them stop the aircraft X at FL290. Sector 89 understood that sector 88 was stopping the aircraft X checks on at FL290. Sector 89 assumes action was taken and calls the traffic to them. The X remains at FL290 until they are 7 mi from the traffic. At this time sector 89 shows the X climbing out of FL290. When the aircraft is questioned they said they were given clearance to FL300. At this time conflict alert is flashing; but the traffic is 7 mi behind and out of FL310. Separation was never lost. Keys to this situation: poor coordination between sector 88/89. Both controllers assumed the other had stopped the aircraft at FL290. X pilot checks climbing to FL290. Never said they had clearance higher; so sector 89 assumes that sector 88 took care of the situation by stopping the aircraft. Separation was never lost; but shows how important clear coordination is.
Original NASA ASRS Text
Title: ZID CTLR DESCRIBED NEAR SEPARATION LOSS AT FL290 WHEN INTRAFAC COORD FAILED AND FAR TOO MANY ASSUMPTIONS WERE MADE BY ALL INVOLVED.
Narrative: SECTOR 88 FLASHED A HDOF ON X CLBING TO FL300. THEY HAD SWITCHED ACFT TO SECTOR 89 AND THEN THEY REALIZED THEY HAD TFC. CALLED SECTOR 89 TO HAVE THEM STOP THE ACFT X AT FL290. SECTOR 89 UNDERSTOOD THAT SECTOR 88 WAS STOPPING THE ACFT X CHKS ON AT FL290. SECTOR 89 ASSUMES ACTION WAS TAKEN AND CALLS THE TFC TO THEM. THE X REMAINS AT FL290 UNTIL THEY ARE 7 MI FROM THE TFC. AT THIS TIME SECTOR 89 SHOWS THE X CLBING OUT OF FL290. WHEN THE ACFT IS QUESTIONED THEY SAID THEY WERE GIVEN CLRNC TO FL300. AT THIS TIME CONFLICT ALERT IS FLASHING; BUT THE TFC IS 7 MI BEHIND AND OUT OF FL310. SEPARATION WAS NEVER LOST. KEYS TO THIS SITUATION: POOR COORD BTWN SECTOR 88/89. BOTH CTLRS ASSUMED THE OTHER HAD STOPPED THE ACFT AT FL290. X PLT CHKS CLBING TO FL290. NEVER SAID THEY HAD CLRNC HIGHER; SO SECTOR 89 ASSUMES THAT SECTOR 88 TOOK CARE OF THE SITUATION BY STOPPING THE ACFT. SEPARATION WAS NEVER LOST; BUT SHOWS HOW IMPORTANT CLR COORD IS.
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.