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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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An ARTCC controller cleared a LR25 aircraft to an occupied altitude then turned the aircraft for separation with a B737 at the same altitude. The LR25 was slow to turn and less than standard separation occurred.
| Attributes | |
| ACN | 357747 |
| Time | |
| Date | 199701 |
| Day | Mon |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : vwv |
| State Reference | OH |
| Altitude | msl bound lower : 37000 msl bound upper : 37000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zob |
| Operator | common carrier : air taxi |
| Make Model Name | Learjet 25 |
| Operating Under FAR Part | Part 135 |
| Flight Phase | cruise other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | cruise other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | oversight : supervisor |
| Qualification | controller : radar |
| Experience | controller radar : 27 controller supervisory : 2 |
| ASRS Report | 357747 |
| Person 2 | |
| Affiliation | company : air taxi |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 75 flight time total : 2800 flight time type : 500 |
| ASRS Report | 357756 |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : published procedure non adherence : required legal separation |
| Independent Detector | atc equipment other atc equipment : unspecified aircraft equipment other aircraft equipment : unspecified other controllera |
| Resolutory Action | controller : issued new clearance flight crew : took evasive action other |
| Consequence | Other |
| Miss Distance | horizontal : 24000 vertical : 200 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
While on duty as area supervisor in charge, a controller issued a direct clearance to cvg from north of rod to an aircraft. This should have resulted in a right turn of 5-10 degrees for the aircraft. Instead, the aircraft turned left 16 degrees and conflicted with an e-nebound air carrier. The air carrier had an RA to climb, but already at FL370 could not, so the air carrier took evasive action to the right. TCASII was not a cause of this error. Supplemental information from acn 357756: 1 min after leveloff at FL370, cleared to rod VOR, ZOB cleared aircraft #1 direct to cvg VOR. Aircraft #1 began turning with autoplt engaged. At approximately 1 min later ARTCC controller advised aircraft #1 to turn to heading 270 degrees immediately and aircraft #2 to turn to heading 090 degrees immediately. Aircraft #2 announced they had a TCASII warning. ARTCC controller announced a learjet was east of course, in response to aircraft #2 inquiry. Original track of aircraft #1 was 193 degrees and new track to cvg was 215 degrees and aircraft #1 was in a continuous right turn at time of event. Supplemental information from acn 357750: PNF noticed turn rate slower than normal on heading bug turn mode of autoplt and began to investigate for autoplt malfunction. ARTCC controller advised aircraft #1 to turn to heading 270 degrees immediately and aircraft #2 to turn to heading 090 degrees immediately. Aircraft #2 announced they had TCASII warning requiring evasive action. ARTCC controller blamed incident (on center frequency) on aircraft #1, saying the learjet was east of assigned track. Excessive deviation from cleared course (protected airspace) seems unlikely. Incident is probable controller error. Aircraft #1 was probably cleared by ATC to climb in error into aircraft #2 protected airspace.
Original NASA ASRS Text
Title: AN ARTCC CTLR CLRED A LR25 ACFT TO AN OCCUPIED ALT THEN TURNED THE ACFT FOR SEPARATION WITH A B737 AT THE SAME ALT. THE LR25 WAS SLOW TO TURN AND LTSS OCCURRED.
Narrative: WHILE ON DUTY AS AREA SUPVR IN CHARGE, A CTLR ISSUED A DIRECT CLRNC TO CVG FROM N OF ROD TO AN ACFT. THIS SHOULD HAVE RESULTED IN A R TURN OF 5-10 DEGS FOR THE ACFT. INSTEAD, THE ACFT TURNED L 16 DEGS AND CONFLICTED WITH AN E-NEBOUND ACR. THE ACR HAD AN RA TO CLB, BUT ALREADY AT FL370 COULD NOT, SO THE ACR TOOK EVASIVE ACTION TO THE R. TCASII WAS NOT A CAUSE OF THIS ERROR. SUPPLEMENTAL INFO FROM ACN 357756: 1 MIN AFTER LEVELOFF AT FL370, CLRED TO ROD VOR, ZOB CLRED ACFT #1 DIRECT TO CVG VOR. ACFT #1 BEGAN TURNING WITH AUTOPLT ENGAGED. AT APPROX 1 MIN LATER ARTCC CTLR ADVISED ACFT #1 TO TURN TO HDG 270 DEGS IMMEDIATELY AND ACFT #2 TO TURN TO HDG 090 DEGS IMMEDIATELY. ACFT #2 ANNOUNCED THEY HAD A TCASII WARNING. ARTCC CTLR ANNOUNCED A LEARJET WAS E OF COURSE, IN RESPONSE TO ACFT #2 INQUIRY. ORIGINAL TRACK OF ACFT #1 WAS 193 DEGS AND NEW TRACK TO CVG WAS 215 DEGS AND ACFT #1 WAS IN A CONTINUOUS R TURN AT TIME OF EVENT. SUPPLEMENTAL INFO FROM ACN 357750: PNF NOTICED TURN RATE SLOWER THAN NORMAL ON HEADING BUG TURN MODE OF AUTOPLT AND BEGAN TO INVESTIGATE FOR AUTOPLT MALFUNCTION. ARTCC CTLR ADVISED ACFT #1 TO TURN TO HDG 270 DEGS IMMEDIATELY AND ACFT #2 TO TURN TO HDG 090 DEGS IMMEDIATELY. ACFT #2 ANNOUNCED THEY HAD TCASII WARNING REQUIRING EVASIVE ACTION. ARTCC CTLR BLAMED INCIDENT (ON CTR FREQ) ON ACFT #1, SAYING THE LEARJET WAS E OF ASSIGNED TRACK. EXCESSIVE DEV FROM CLRED COURSE (PROTECTED AIRSPACE) SEEMS UNLIKELY. INCIDENT IS PROBABLE CTLR ERROR. ACFT #1 WAS PROBABLY CLRED BY ATC TO CLB IN ERROR INTO ACFT #2 PROTECTED AIRSPACE.
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.