Less than standard separation between two military aircraft. Pilot deviation.

Attributes
ACN	100184
Time
Date	198812
Day	Fri
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : saw
State Reference	MI
Altitude	msl bound lower : 20000 msl bound upper : 20500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zmp
Operator	other
Make Model Name	Experimental
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Military Transport
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	100184
Person 2
Affiliation	government : military
Function	flight crew : captain oversight : pic
Qualification	pilot : military
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : clearance other spatial deviation
Independent Detector	other other : unspecified atc
Resolutory Action	controller : issued new clearance none taken : unable other
Consequence	faa : investigated
Miss Distance	horizontal : 24000 vertical : 500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Spc X was in the block FL190 B210. Bmb Y in the block FL220 B240. Bmb Y was 10 mit doing comparatively the same speed. Spc X and bmb Y were both proceeding direct saw spc X requested 10 mi north and south of course which was approved. Bmb Y requested lower and was given 130. The next minute X was converging with Y. I asked him his heading he said 030 degree. I didn't expect him to turn 120 degree. I then turned bmb Y to 360 degree and spc X to 270, to increase sep, I then asked bmb Y his altitude, he said FL205. I then asked X his altitude, he said FL200. I then assigned FL210 to bmb Y. By the time he reached FL210 lateral sep had been reestablished.

Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN TWO MIL ACFT. PLT DEVIATION.

Narrative: SPC X WAS IN THE BLOCK FL190 B210. BMB Y IN THE BLOCK FL220 B240. BMB Y WAS 10 MIT DOING COMPARATIVELY THE SAME SPD. SPC X AND BMB Y WERE BOTH PROCEEDING DIRECT SAW SPC X REQUESTED 10 MI N AND S OF COURSE WHICH WAS APPROVED. BMB Y REQUESTED LOWER AND WAS GIVEN 130. THE NEXT MINUTE X WAS CONVERGING WITH Y. I ASKED HIM HIS HDG HE SAID 030 DEG. I DIDN'T EXPECT HIM TO TURN 120 DEG. I THEN TURNED BMB Y TO 360 DEG AND SPC X TO 270, TO INCREASE SEP, I THEN ASKED BMB Y HIS ALT, HE SAID FL205. I THEN ASKED X HIS ALT, HE SAID FL200. I THEN ASSIGNED FL210 TO BMB Y. BY THE TIME HE REACHED FL210 LATERAL SEP HAD BEEN REESTABLISHED.

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.