Air carrier Y had less than standard separation from air carrier X. System error.

Attributes
ACN	122249
Time
Date	198908
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zny
State Reference	NY
Altitude	msl bound lower : 21000 msl bound upper : 22300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	122249
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 21000 vertical : 700
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I, the controller, had an operational error. An air carrier X jet was climbing out at 250 KTS on J80. Air carrier Y was following. I climbed the air carrier X to FL260 and resumed normal airspeed. When he left FL210 I climbed air carrier Y to FL210. I then questioned air carrier X's speed (2 mins after resuming it). He said he was 'increasing out of 250.' I told air carrier X to increase to 300 KTS. And to level off if he had to. When I saw air carrier X had left FL223, I climbed air carrier Y to FL220. I then asked air carrier X to report leaving FL230. He said, 'we're level at 223.' I then immediately stopped the air carrier Y climb and amended it back to FL210. The air carrier Y had broken through FL210 and the resultant sep was 700' and 3.5 mi. Neither aircraft was informed of the error. Although sep was lost, I feel there was still safety maintained at all times.

Original NASA ASRS Text

Title: ACR Y HAD LESS THAN STANDARD SEPARATION FROM ACR X. SYSTEM ERROR.

Narrative: I, THE CTLR, HAD AN OPERROR. AN ACR X JET WAS CLBING OUT AT 250 KTS ON J80. ACR Y WAS FOLLOWING. I CLBED THE ACR X TO FL260 AND RESUMED NORMAL AIRSPD. WHEN HE LEFT FL210 I CLBED ACR Y TO FL210. I THEN QUESTIONED ACR X'S SPD (2 MINS AFTER RESUMING IT). HE SAID HE WAS 'INCREASING OUT OF 250.' I TOLD ACR X TO INCREASE TO 300 KTS. AND TO LEVEL OFF IF HE HAD TO. WHEN I SAW ACR X HAD LEFT FL223, I CLBED ACR Y TO FL220. I THEN ASKED ACR X TO RPT LEAVING FL230. HE SAID, 'WE'RE LEVEL AT 223.' I THEN IMMEDIATELY STOPPED THE ACR Y CLB AND AMENDED IT BACK TO FL210. THE ACR Y HAD BROKEN THROUGH FL210 AND THE RESULTANT SEP WAS 700' AND 3.5 MI. NEITHER ACFT WAS INFORMED OF THE ERROR. ALTHOUGH SEP WAS LOST, I FEEL THERE WAS STILL SAFETY MAINTAINED AT ALL TIMES.

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.