Military X climbing had less than standard separation from air carrier Y descending. System error.

Attributes
ACN	273451
Time
Date	199406
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ctr
State Reference	MA
Altitude	msl bound lower : 13500 msl bound upper : 13500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	other
Make Model Name	Hercules (C-130)
Operating Under FAR Part	other : other
Flight Phase	descent other
Route In Use	enroute : direct enroute airway : zbw
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Dash 8 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 135
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller non radar : 5 controller radar : 7
ASRS Report	273451
Person 2
Affiliation	government : military
Function	flight crew : captain oversight : pic
Qualification	pilot : military
Events
Anomaly	conflict : airborne less severe non adherence : clearance non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	controller : issued new clearance other
Consequence	faa : investigated
Miss Distance	horizontal : 22800 vertical : 900
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Climbed military X to 170 on contact. Descended air carrier Y to enable shortcut to gdm and clear X. Obtained authorization from receiving controller and issued direct gdm to Y. Aircraft was south of normal track and therefore had dri (distance indicator -- 6 mi circle) still in effect. Did scan and took actions with other aircraft and data blocks. Saw what appeared to be turn toward gdm by Y. Continued scan and then noticed Y had not actually turned -- still tracking to center or slightly north. Issued turns to both aircraft to maintain separation. Issued additional turns but not in sufficient time to avoid loss of separation. When re-established returned aircraft on course. Y did not turn toward gdm plus wind usually takes aircraft further east of course. Continued observation may have given an earlier indication that Y not in turn and corrective action might have been more effective. Conflict alert did not activate in sufficient time as X was turning on course and projected track was north of route.

Original NASA ASRS Text

Title: MIL X CLBING HAD LTSS FROM ACR Y DSNDING. SYS ERROR.

Narrative: CLBED MIL X TO 170 ON CONTACT. DSNDED ACR Y TO ENABLE SHORTCUT TO GDM AND CLR X. OBTAINED AUTHORIZATION FROM RECEIVING CTLR AND ISSUED DIRECT GDM TO Y. ACFT WAS S OF NORMAL TRACK AND THEREFORE HAD DRI (DISTANCE INDICATOR -- 6 MI CIRCLE) STILL IN EFFECT. DID SCAN AND TOOK ACTIONS WITH OTHER ACFT AND DATA BLOCKS. SAW WHAT APPEARED TO BE TURN TOWARD GDM BY Y. CONTINUED SCAN AND THEN NOTICED Y HAD NOT ACTUALLY TURNED -- STILL TRACKING TO CTR OR SLIGHTLY N. ISSUED TURNS TO BOTH ACFT TO MAINTAIN SEPARATION. ISSUED ADDITIONAL TURNS BUT NOT IN SUFFICIENT TIME TO AVOID LOSS OF SEPARATION. WHEN RE-ESTABLISHED RETURNED ACFT ON COURSE. Y DID NOT TURN TOWARD GDM PLUS WIND USUALLY TAKES ACFT FURTHER E OF COURSE. CONTINUED OBSERVATION MAY HAVE GIVEN AN EARLIER INDICATION THAT Y NOT IN TURN AND CORRECTIVE ACTION MIGHT HAVE BEEN MORE EFFECTIVE. CONFLICT ALERT DID NOT ACTIVATE IN SUFFICIENT TIME AS X WAS TURNING ON COURSE AND PROJECTED TRACK WAS N OF RTE.

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.