|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||atc facility : auo|
|Altitude||msl bound lower : 8400|
msl bound upper : 9000
|Operator||general aviation : corporate|
|Make Model Name||Small Transport, Low Wing, 2 Recip Eng|
|Flight Phase||descent other|
|Route In Use||enroute airway : mgm|
|Make Model Name||Any Unknown or Unlisted Aircraft Manufacturer|
|Flight Phase||cruise other|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 90|
flight time total : 7000
flight time type : 500
|Function||controller : approach|
|Qualification||controller : radar|
|Anomaly||conflict : airborne less severe|
|Independent Detector||other controllera|
|Resolutory Action||none taken : unable|
|Miss Distance||horizontal : 18000|
vertical : 600
|Primary Problem||ATC Human Performance|
|Air Traffic Incident||other|
On an IFR flight plan, an initial contact to mgm approach control was made. The controller asked our position because he stated he did not have a flight strip on us. While maintaining 11000' a clearance was received to expedite descent through 9000', descend and maintain 6000'. The clearance was acknowledged and a rate of descent of approximately 1000 FPM was used through 9000'. At approximately 8600' the descent rate was slowed to 500-600 FPM. The controller started calling out traffic at 1 O'clock, then at 3 O'clock at 9000' and 3 1/2 mi. He started reading us the riot act about not expediting our descent. I told him we followed the clearance through 9000', then because we were unpressurized and entering the cloud tops, we were slowing our rate to 500-600 FPM. After thinking about it, it appears the controller made a mistake and was trying to put the blame on us over the radio. If the conflicting traffic was at 9000', then the clearance should have been to expedite to 8000', descend and maintain 6000'.
Original NASA ASRS Text
Title: ALMOST LESS THAN STANDARD SEPARATION BETWEEN OPPOSITE DIRECTION TRAFFIC ON SAME AIRWAY.
Narrative: ON AN IFR FLT PLAN, AN INITIAL CONTACT TO MGM APCH CTL WAS MADE. THE CTLR ASKED OUR POS BECAUSE HE STATED HE DID NOT HAVE A FLT STRIP ON US. WHILE MAINTAINING 11000' A CLRNC WAS RECEIVED TO EXPEDITE DSCNT THROUGH 9000', DSND AND MAINTAIN 6000'. THE CLRNC WAS ACKNOWLEDGED AND A RATE OF DSCNT OF APPROX 1000 FPM WAS USED THROUGH 9000'. AT APPROX 8600' THE DSCNT RATE WAS SLOWED TO 500-600 FPM. THE CTLR STARTED CALLING OUT TFC AT 1 O'CLOCK, THEN AT 3 O'CLOCK AT 9000' AND 3 1/2 MI. HE STARTED READING US THE RIOT ACT ABOUT NOT EXPEDITING OUR DSCNT. I TOLD HIM WE FOLLOWED THE CLRNC THROUGH 9000', THEN BECAUSE WE WERE UNPRESSURIZED AND ENTERING THE CLOUD TOPS, WE WERE SLOWING OUR RATE TO 500-600 FPM. AFTER THINKING ABOUT IT, IT APPEARS THE CTLR MADE A MISTAKE AND WAS TRYING TO PUT THE BLAME ON US OVER THE RADIO. IF THE CONFLICTING TFC WAS AT 9000', THEN THE CLRNC SHOULD HAVE BEEN TO EXPEDITE TO 8000', DSND AND MAINTAIN 6000'.
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.