Potential loss of standard separation between air carrier X and mlt Y.

Attributes
ACN	147553
Time
Date	199006
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bos
State Reference	MA
Altitude	msl bound lower : 13000 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Military Transport
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller military : 2 controller non radar : 3 controller radar : 5
ASRS Report	147553
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	other
Consequence	Other
Miss Distance	horizontal : 36000 vertical : 1000
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

While working as the radar controller I had air carrier X (route bgr-scupp-bos) in a descent to FL110. The other aircraft was mlt Y (route psm-scupp-floun poggo lpla) was climbing to FL230. When conflict alert activated I issued a crossing restriction to air carrier X (40 east of bus at FL110). Conflict alert discontinued. As I monitored the descent and climb of both aircraft I realized that sep was going to be lost. I told air carrier X to expedite to FL150, air carrier X reported out of FL130 approximately 6 mi east of mlt Y. Although sep was not lost, I failed to insure sep by using a crossing restriction that I assumed would have air carrier X below mlt Y. I believe the air carrier X (traffic was observed) had turned his aircraft as well as descended to avoid mlt Y. The action I took initially when conflict alert activated, I feel was correct, however, the crossing restriction used was no good. Other traffic prevent the use of vectors on either aircraft. I underestimated the climb rate of mlt Y. The correct restriction needed was for air carrier X to cross at least 45 mi east of boston approximately FL130 to insure sep.

Original NASA ASRS Text

Title: POTENTIAL LOSS OF STANDARD SEPARATION BETWEEN ACR X AND MLT Y.

Narrative: WHILE WORKING AS THE RADAR CTLR I HAD ACR X (RTE BGR-SCUPP-BOS) IN A DSNT TO FL110. THE OTHER ACFT WAS MLT Y (RTE PSM-SCUPP-FLOUN POGGO LPLA) WAS CLBING TO FL230. WHEN CONFLICT ALERT ACTIVATED I ISSUED A XING RESTRICTION TO ACR X (40 E OF BUS AT FL110). CONFLICT ALERT DISCONTINUED. AS I MONITORED THE DSNT AND CLB OF BOTH ACFT I REALIZED THAT SEP WAS GOING TO BE LOST. I TOLD ACR X TO EXPEDITE TO FL150, ACR X RPTED OUT OF FL130 APPROX 6 MI E OF MLT Y. ALTHOUGH SEP WAS NOT LOST, I FAILED TO INSURE SEP BY USING A XING RESTRICTION THAT I ASSUMED WOULD HAVE ACR X BELOW MLT Y. I BELIEVE THE ACR X (TFC WAS OBSERVED) HAD TURNED HIS ACFT AS WELL AS DSNDED TO AVOID MLT Y. THE ACTION I TOOK INITIALLY WHEN CONFLICT ALERT ACTIVATED, I FEEL WAS CORRECT, HOWEVER, THE XING RESTRICTION USED WAS NO GOOD. OTHER TFC PREVENT THE USE OF VECTORS ON EITHER ACFT. I UNDERESTIMATED THE CLB RATE OF MLT Y. THE CORRECT RESTRICTION NEEDED WAS FOR ACR X TO CROSS AT LEAST 45 MI E OF BOSTON APPROX FL130 TO INSURE SEP.

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.