Military aircraft Y had less than standard separation from military aircraft X. System error.

Attributes
ACN	127673
Time
Date	198911
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ska
State Reference	WA
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	military facility : ska tracon : geg
Operator	other
Make Model Name	Military Trainer
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Experimental
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller radar : 1
ASRS Report	127673
Person 2
Affiliation	government : military
Function	other personnel other
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	unspecified : 12000 vertical : 100
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Military aircraft X MTR was in the radar traffic pattern at fairchild AFB for multiple apches. Military aircraft Y spc was in the radar traffic pattern at fairchild AFB for multiple apches. I was working the MTR on an ILS approach and had handed off military aircraft Y to the washington air national guard conducting gca apches. Military aircraft Y was turned onto final approximately 8 mi in trail of military aircraft X. During this time I had 6 other aircraft on my frequency, that I was talking to, including a marsa flight that had receiver problems. I had to keep contacting them on the UHF emergency frequency 243.0. I noticed that the separation between military aircraft X and military aircraft Y had diminished to approximately 2 mi in trail. At this time I asked the military aircraft X his airspeed. His reply was 110 KTS. I told him to keep his speed up. I then contacted the cga on the hotline and told them to turn military aircraft Y right to 300 degree and climb him to 5000' MSL. While military aircraft Y was in his turn and returned to my frequency, I issued traffic and the pilot reported military aircraft X in sight. Fairchild AFB does not normally have a gca. The temporary gca that was in operation at the time of the occurrence is made up of members of the washington air national guard.

Original NASA ASRS Text

Title: MIL ACFT Y HAD LESS THAN STANDARD SEPARATION FROM MIL ACFT X. SYSTEM ERROR.

Narrative: MIL ACFT X MTR WAS IN THE RADAR TFC PATTERN AT FAIRCHILD AFB FOR MULTIPLE APCHES. MIL ACFT Y SPC WAS IN THE RADAR TFC PATTERN AT FAIRCHILD AFB FOR MULTIPLE APCHES. I WAS WORKING THE MTR ON AN ILS APCH AND HAD HANDED OFF MIL ACFT Y TO THE WASHINGTON AIR NATIONAL GUARD CONDUCTING GCA APCHES. MIL ACFT Y WAS TURNED ONTO FINAL APPROX 8 MI IN TRAIL OF MIL ACFT X. DURING THIS TIME I HAD 6 OTHER ACFT ON MY FREQ, THAT I WAS TALKING TO, INCLUDING A MARSA FLT THAT HAD RECEIVER PROBLEMS. I HAD TO KEEP CONTACTING THEM ON THE UHF EMER FREQ 243.0. I NOTICED THAT THE SEPARATION BETWEEN MIL ACFT X AND MIL ACFT Y HAD DIMINISHED TO APPROX 2 MI IN TRAIL. AT THIS TIME I ASKED THE MIL ACFT X HIS AIRSPEED. HIS REPLY WAS 110 KTS. I TOLD HIM TO KEEP HIS SPEED UP. I THEN CONTACTED THE CGA ON THE HOTLINE AND TOLD THEM TO TURN MIL ACFT Y RIGHT TO 300 DEG AND CLIMB HIM TO 5000' MSL. WHILE MIL ACFT Y WAS IN HIS TURN AND RETURNED TO MY FREQ, I ISSUED TFC AND THE PLT REPORTED MIL ACFT X IN SIGHT. FAIRCHILD AFB DOES NOT NORMALLY HAVE A GCA. THE TEMPORARY GCA THAT WAS IN OPERATION AT THE TIME OF THE OCCURRENCE IS MADE UP OF MEMBERS OF THE WASHINGTON AIR NATIONAL GUARD.

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.