|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1801 To 2400|
|Locale Reference||airport : bwi.airport|
|Altitude||msl single value : 5000|
|Controlling Facilities||tracon : pct.tracon|
|Operator||common carrier : air carrier|
|Make Model Name||A320|
|Operating Under FAR Part||Part 121|
|Flight Phase||descent : approach|
|Route In Use||arrival : on vectors|
|Affiliation||government : faa|
|Function||controller : approach|
|Qualification||controller : radar|
pilot : instrument
|Experience||controller radar : 9|
flight time total : 280
|Anomaly||conflict : airborne less severe|
non adherence : required legal separation
|Independent Detector||other controllera|
|Resolutory Action||flight crew : took evasive action|
|Consequence||faa : investigated|
|Miss Distance||horizontal : 12000|
vertical : 500
|Primary Problem||ATC Human Performance|
|Air Traffic Incident||Operational Error|
I vectored the A320 to the northeast to follow traffic landing bwi. I issued the A320 a descent to 5000 ft and reduced speed to 210 KTS. He read back 180 KTS and I did not correct him because 180 KTS was a better choice. I then cleared the A320 to 4000 ft and issued 170 KTS. Approximately 1 min and 20 seconds later; I noticed a C421 sebound at 5000 ft on an adjacent controller's frequency. I also noticed that the A320 was still at 5000 ft. I issued traffic to the A320 to turn and descend immediately to 3000 ft. I heard the A320; in his reply; turn off the autoplt (beep; beep; beep) and started descending out of 5000 ft. In my opinion; the A320 did not begin his descent in a timely manner from 5000 ft to 4000 ft. If he had; I believe separation would have been maintained.
Original NASA ASRS Text
Title: PCT CTLR EXPERIENCED OPERROR AT 5000 WHEN ACFT WAS SLOW IN BEGINNING DESCENT AND CONFLICTED WITH TFC IN ADJACENT SECTOR.
Narrative: I VECTORED THE A320 TO THE NE TO FOLLOW TFC LNDG BWI. I ISSUED THE A320 A DSCNT TO 5000 FT AND REDUCED SPD TO 210 KTS. HE READ BACK 180 KTS AND I DID NOT CORRECT HIM BECAUSE 180 KTS WAS A BETTER CHOICE. I THEN CLRED THE A320 TO 4000 FT AND ISSUED 170 KTS. APPROX 1 MIN AND 20 SECONDS LATER; I NOTICED A C421 SEBOUND AT 5000 FT ON AN ADJACENT CTLR'S FREQ. I ALSO NOTICED THAT THE A320 WAS STILL AT 5000 FT. I ISSUED TFC TO THE A320 TO TURN AND DSND IMMEDIATELY TO 3000 FT. I HEARD THE A320; IN HIS REPLY; TURN OFF THE AUTOPLT (BEEP; BEEP; BEEP) AND STARTED DSNDING OUT OF 5000 FT. IN MY OPINION; THE A320 DID NOT BEGIN HIS DSCNT IN A TIMELY MANNER FROM 5000 FT TO 4000 FT. IF HE HAD; I BELIEVE SEPARATION WOULD HAVE BEEN MAINTAINED.
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.