Less than legal separation of 2 aircraft on climb.

Attributes
ACN	311131
Time
Date	199507
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : djb
State Reference	OH
Altitude	msl bound lower : 15000 msl bound upper : 16000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob tower : atl
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	Gulfstream III
Operating Under FAR Part	Part 91
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	311131
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	other controllera
Resolutory Action	other
Consequence	Other
Miss Distance	horizontal : 24600 vertical : 300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Aircraft X, an E120, was a cle departure en route to buf climbing to 17000 ft via the djb 054 degree radial.fails./.buf. Aircraft Y, an RNAV equipped G3, was a cle departure en route to hpn climbing to 13000 ft via the djb 054 degree radial.fails.dny,VALRE2.hpn. X had left 13000 ft in his climb. Immediately after issuing 13000 ft to Y, I cleared him direct to dny, which he read back in acknowledgement. Approximately 1 min later Y questioned the direct clearance. Again, I issued direct dny and a climb clearance to FL230, both of which he acknowledged. Approximately 30 seconds later, having stopped X at 15000 ft, I realized that I would not have sufficient vertical separation once lateral separation was lost. Y was turned right to a 120 degree heading for traffic. Moments later, Y was observed leaving 16000 ft, and reclred direct dny. At this point Y asked for the spelling of dny, which I missed. 90 seconds later, Y asked for the 3-LETTER identify for dny, to which I responded phonetically. 3 mins and 30 seconds elapsed from the time Y initially read back the direct clearance, and finally was made to understand the direct clearance.

Original NASA ASRS Text

Title: LESS THAN LEGAL SEPARATION OF 2 ACFT ON CLB.

Narrative: ACFT X, AN E120, WAS A CLE DEP ENRTE TO BUF CLBING TO 17000 FT VIA THE DJB 054 DEG RADIAL.FAILS./.BUF. ACFT Y, AN RNAV EQUIPPED G3, WAS A CLE DEP ENRTE TO HPN CLBING TO 13000 FT VIA THE DJB 054 DEG RADIAL.FAILS.DNY,VALRE2.HPN. X HAD LEFT 13000 FT IN HIS CLB. IMMEDIATELY AFTER ISSUING 13000 FT TO Y, I CLRED HIM DIRECT TO DNY, WHICH HE READ BACK IN ACKNOWLEDGEMENT. APPROX 1 MIN LATER Y QUESTIONED THE DIRECT CLRNC. AGAIN, I ISSUED DIRECT DNY AND A CLB CLRNC TO FL230, BOTH OF WHICH HE ACKNOWLEDGED. APPROX 30 SECONDS LATER, HAVING STOPPED X AT 15000 FT, I REALIZED THAT I WOULD NOT HAVE SUFFICIENT VERT SEPARATION ONCE LATERAL SEPARATION WAS LOST. Y WAS TURNED R TO A 120 DEG HDG FOR TFC. MOMENTS LATER, Y WAS OBSERVED LEAVING 16000 FT, AND RECLRED DIRECT DNY. AT THIS POINT Y ASKED FOR THE SPELLING OF DNY, WHICH I MISSED. 90 SECONDS LATER, Y ASKED FOR THE 3-LETTER IDENT FOR DNY, TO WHICH I RESPONDED PHONETICALLY. 3 MINS AND 30 SECONDS ELAPSED FROM THE TIME Y INITIALLY READ BACK THE DIRECT CLRNC, AND FINALLY WAS MADE TO UNDERSTAND THE DIRECT CLRNC.

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.