Mdt made slow rate of climb and came in close proximity to opposite direction traffic.

Attributes
ACN	108213
Time
Date	198904
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sby
State Reference	MD
Altitude	msl bound lower : 37000 msl bound upper : 39000
Environment
Flight Conditions	Marginal
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	Medium Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 2
ASRS Report	108213
Person 2
Affiliation	government : faa
Function	controller : flight data
Qualification	controller : developmental
Experience	controller military : 2
ASRS Report	108417
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	controller : issued new clearance other
Consequence	faa : investigated
Miss Distance	horizontal : 25200 vertical : 1300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Widebody transport was northbound at FL370. Opp direction was mdt climbing out of FL370 to FL390. I accepted a handoff on mdt with 40-50 mi between aircraft. I noticed mdt had slow rate of climb. I asked him to expedite his climb. C/a went off with approximately 30 mi between them and I turned the mdt 20 degrees left. Then I turned widebody transport 10 degrees left to ensure sep latitude. The widebody transport never deviated from his route. I turned mdt further left to 150 degrees heading and the widebody transport to 340 degree heading. Still the widebody transport didn't seem to turn. The mode C readout on the mdt showed FL386 and then dropped back down to FL382 as he turned. Sep was then lost (4.3 mi and 1300'). 2 factors caused this error: 1) widebody transport acknowledged for his turns but never turned; 2) mdt could not even maintain altitude, let alone climb and descend while in the turn. I felt I had taken appropriate action in plenty of time.

Original NASA ASRS Text

Title: MDT MADE SLOW RATE OF CLIMB AND CAME IN CLOSE PROX TO OPPOSITE DIRECTION TRAFFIC.

Narrative: WDB WAS NBOUND AT FL370. OPP DIRECTION WAS MDT CLBING OUT OF FL370 TO FL390. I ACCEPTED A HDOF ON MDT WITH 40-50 MI BTWN ACFT. I NOTICED MDT HAD SLOW RATE OF CLB. I ASKED HIM TO EXPEDITE HIS CLB. C/A WENT OFF WITH APPROX 30 MI BTWN THEM AND I TURNED THE MDT 20 DEGS LEFT. THEN I TURNED WDB 10 DEGS LEFT TO ENSURE SEP LAT. THE WDB NEVER DEVIATED FROM HIS ROUTE. I TURNED MDT FURTHER LEFT TO 150 DEGS HDG AND THE WDB TO 340 DEG HDG. STILL THE WDB DIDN'T SEEM TO TURN. THE MODE C READOUT ON THE MDT SHOWED FL386 AND THEN DROPPED BACK DOWN TO FL382 AS HE TURNED. SEP WAS THEN LOST (4.3 MI AND 1300'). 2 FACTORS CAUSED THIS ERROR: 1) WDB ACKNOWLEDGED FOR HIS TURNS BUT NEVER TURNED; 2) MDT COULD NOT EVEN MAINTAIN ALT, LET ALONE CLB AND DSND WHILE IN THE TURN. I FELT I HAD TAKEN APPROPRIATE ACTION IN PLENTY OF TIME.

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.