Less than standard separation between 2 air carrier aircraft. Operational error.

Attributes
ACN	98136
Time
Date	198811
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : orw
State Reference	CT
Altitude	msl bound lower : 13000 msl bound upper : 13100
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute airway : v475
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	98136
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : developmental
ASRS Report	98134
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	other other : unspecified atc
Resolutory Action	controller : issued new clearance none taken : unable none taken : insufficient time
Consequence	faa : investigated
Miss Distance	horizontal : 21000 vertical : 100
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Training was in progress. There were approximately 8 aircraft on frequency (128.75). Air carrier X was en route to bos from mad-orw-pvd-V151-ind-bos at FL210 over mad. Air carrier Y was en route from bdl-orw-pvd-V151-ind-bos at 13000'. The 2 aircraft were on converging routes towards orw. Air carrier X was issued a clearance to cross pvd at 11000' and 250 KTS. At this time I intended to correct the trnee to change the clearance to 14000' and use positive control, however my attention was diverted to another control situation in our sector. This situation required 2 or 3 interphone calls with 2 other sectors (sardi/erick-sector 32/33 and hampton, sector 31). By the time we got back to air carrier X and Y, air carrier X was within 5 mi of Y. Air carrier X still showed 14700' and the trnee told air carrier X to maintain 14000' (air carrier Y is still at 13000'). Air carrier X said he was out of 13500' and would climb back to 14000'. By the time he could stop descent and climb, he leveled at 13100'. The ntap showed 3.5 mi latitude and 100' vertical. Air carrier Y was then descended to 11000' and turned right while X climbed to 14000'.

Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN 2 ACR ACFT. OPERATIONAL ERROR.

Narrative: TRNING WAS IN PROGRESS. THERE WERE APPROX 8 ACFT ON FREQ (128.75). ACR X WAS ENRTE TO BOS FROM MAD-ORW-PVD-V151-IND-BOS AT FL210 OVER MAD. ACR Y WAS ENRTE FROM BDL-ORW-PVD-V151-IND-BOS AT 13000'. THE 2 ACFT WERE ON CONVERGING ROUTES TOWARDS ORW. ACR X WAS ISSUED A CLRNC TO CROSS PVD AT 11000' AND 250 KTS. AT THIS TIME I INTENDED TO CORRECT THE TRNEE TO CHANGE THE CLRNC TO 14000' AND USE POSITIVE CTL, HOWEVER MY ATTN WAS DIVERTED TO ANOTHER CTL SITUATION IN OUR SECTOR. THIS SITUATION REQUIRED 2 OR 3 INTERPHONE CALLS WITH 2 OTHER SECTORS (SARDI/ERICK-SECTOR 32/33 AND HAMPTON, SECTOR 31). BY THE TIME WE GOT BACK TO ACR X AND Y, ACR X WAS WITHIN 5 MI OF Y. ACR X STILL SHOWED 14700' AND THE TRNEE TOLD ACR X TO MAINTAIN 14000' (ACR Y IS STILL AT 13000'). ACR X SAID HE WAS OUT OF 13500' AND WOULD CLB BACK TO 14000'. BY THE TIME HE COULD STOP DSCNT AND CLB, HE LEVELED AT 13100'. THE NTAP SHOWED 3.5 MI LAT AND 100' VERT. ACR Y WAS THEN DSNDED TO 11000' AND TURNED RIGHT WHILE X CLBED TO 14000'.

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.