Air carrier Y had less than standard separation from air carrier X. Pilot deviation.

Attributes
ACN	175789
Time
Date	199104
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : dsm
State Reference	IA
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zmp
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller military : 4 controller radar : 3
ASRS Report	175789
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 other atc equipment : unspecified other controllera
Resolutory Action	none taken : anomaly accepted
Consequence	faa : investigated
Miss Distance	horizontal : 27000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Southbound air carrier X at FL350 in conflict with westbound air carrier Y at FL350. The northwest vector issued to air carrier Y was not enough to maintain sep. Callback conversation with reporter revealed the following: reporter stated air carrier X and Y were medium large transport's the reporter was shooting a hole with air carrier X between 2 westbound aircraft. C/a had activated but the reporter ignored it because he had taken action and thought he would have standard sep. Sep was lost on the back side of air carrier X.

Original NASA ASRS Text

Title: ACR Y HAD LESS THAN STANDARD SEPARATION FROM ACR X. PLT DEVIATION.

Narrative: SBND ACR X AT FL350 IN CONFLICT WITH WBND ACR Y AT FL350. THE NW VECTOR ISSUED TO ACR Y WAS NOT ENOUGH TO MAINTAIN SEP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR STATED ACR X AND Y WERE MLG'S THE RPTR WAS SHOOTING A HOLE WITH ACR X BTWN 2 WBND ACFT. C/A HAD ACTIVATED BUT THE RPTR IGNORED IT BECAUSE HE HAD TAKEN ACTION AND THOUGHT HE WOULD HAVE STANDARD SEP. SEP WAS LOST ON THE BACK SIDE OF ACR X.

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.