Aircraft #1 descended through aircraft #2's altitude, resulting in less than standard separation.

Attributes
ACN	110931
Time
Date	198905
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sav
State Reference	GA
Altitude	msl bound lower : 23000 msl bound upper : 22000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx
Operator	other
Make Model Name	Fighter
Flight Phase	descent other
Route In Use	arrival other enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Fighter
Flight Phase	cruise other
Route In Use	arrival other enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 15
ASRS Report	110931
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted none taken : detected after the fact none taken : insufficient time
Consequence	faa : investigated
Miss Distance	horizontal : 24000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Descended aircraft #1 through aircraft #2's altitude with less than 5 mi sep. Callback conversation with reporter revealed the following: reporter had been briefed and had just relieved the position. Aircraft #1 and #2 were military fgt's returning from a tac mission. Aircraft #1 was descending to FL230, 4 mi ahead of and 50 KTS faster than aircraft #2. Aircraft #2 was level at FL220. When aircraft #1 was 5 mi in front of aircraft #2 descent to 12000' was issued to aircraft #1. Aircraft #1 had slowed and sep was lost. The reporter notified the supervisor and 3 seconds later the C/a went off. Traffic was not issued and the aircraft did not see each other.

Original NASA ASRS Text

Title: ACFT #1 DESCENDED THROUGH ACFT #2'S ALT, RESULTING IN LESS THAN STANDARD SEPARATION.

Narrative: DSNDED ACFT #1 THROUGH ACFT #2'S ALT WITH LESS THAN 5 MI SEP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR HAD BEEN BRIEFED AND HAD JUST RELIEVED THE POS. ACFT #1 AND #2 WERE MIL FGT'S RETURNING FROM A TAC MISSION. ACFT #1 WAS DSNDING TO FL230, 4 MI AHEAD OF AND 50 KTS FASTER THAN ACFT #2. ACFT #2 WAS LEVEL AT FL220. WHEN ACFT #1 WAS 5 MI IN FRONT OF ACFT #2 DSCNT TO 12000' WAS ISSUED TO ACFT #1. ACFT #1 HAD SLOWED AND SEP WAS LOST. THE RPTR NOTIFIED THE SUPVR AND 3 SECS LATER THE C/A WENT OFF. TFC WAS NOT ISSUED AND THE ACFT DID NOT SEE EACH OTHER.

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.