ZID ARTCC radar controller descends an air carrier to an occupied altitude resulting in a loss of se...

Attributes
ACN	527288
Time
Date	200110
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : lvt.vortac
State Reference	TN
Altitude	msl single value : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller military : 3 controller radar : 12.5 controller time certified in position1 : 9.5
ASRS Report	527288
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera
Resolutory Action	none taken : anomaly accepted
Miss Distance	horizontal : 18000 vertical : 1500
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I wanted to descend aircraft #1 to FL330, my base altitude. There was another aircraft right below at FL310. I had to get the first aircraft to FL310. I put FL310 in as an assigned altitude, then put FL330 as a temporary altitude. FL310 went through my head 3 times. I think it stuck. The first aircraft checked on the next frequency right over our transmitter. It was broken up so his actual assigned altitude was missed. I had actually descended the first aircraft to FL310.

Original NASA ASRS Text

Title: ZID ARTCC RADAR CTLR DSNDS AN ACR TO AN OCCUPIED ALT RESULTING IN A LOSS OF SEPARATION.

Narrative: I WANTED TO DSND ACFT #1 TO FL330, MY BASE ALT. THERE WAS ANOTHER ACFT RIGHT BELOW AT FL310. I HAD TO GET THE FIRST ACFT TO FL310. I PUT FL310 IN AS AN ASSIGNED ALT, THEN PUT FL330 AS A TEMPORARY ALT. FL310 WENT THROUGH MY HEAD 3 TIMES. I THINK IT STUCK. THE FIRST ACFT CHKED ON THE NEXT FREQ RIGHT OVER OUR XMITTER. IT WAS BROKEN UP SO HIS ACTUAL ASSIGNED ALT WAS MISSED. I HAD ACTUALLY DSNDED THE FIRST ACFT TO FL310.

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.

ZID ARTCC radar controller descends an air carrier to an occupied altitude resulting in a loss of separation.