Radar separation was lost when ARTCC radar controller descended an aircraft into head-on traffic.

Attributes
ACN	154227
Time
Date	199008
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pvd
State Reference	RI
Altitude	msl bound lower : 12000 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	154227
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	faa : investigated
Miss Distance	horizontal : 24000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Light transport flying from ack to ewr via pvd and baf. Medium large transport flying to bos via madison pvd. Medium large transport descending to cross pvd at 11000'. Light transport at 12000' on a vector to baf to keep aircraft south of pvd where arrs to bos cross at 11000'. I attempted in 5-6 xmissions to issue 13000' to medium large transport in plenty of time to avoid loss of sep. Mlt apparently had radio problems and did not respond. Light transport also attempted to contact medium large transport. When he did respond it was too late. Light transport was issued left turn 30 degrees to keep 5 NM--not enough or too late.

Original NASA ASRS Text

Title: RADAR SEPARATION WAS LOST WHEN ARTCC RADAR CTLR DESCENDED AN ACFT INTO HEAD-ON TRAFFIC.

Narrative: LTT FLYING FROM ACK TO EWR VIA PVD AND BAF. MLG FLYING TO BOS VIA MADISON PVD. MLG DSNDING TO CROSS PVD AT 11000'. LTT AT 12000' ON A VECTOR TO BAF TO KEEP ACFT S OF PVD WHERE ARRS TO BOS CROSS AT 11000'. I ATTEMPTED IN 5-6 XMISSIONS TO ISSUE 13000' TO MLG IN PLENTY OF TIME TO AVOID LOSS OF SEP. MLT APPARENTLY HAD RADIO PROBS AND DID NOT RESPOND. LTT ALSO ATTEMPTED TO CONTACT MLG. WHEN HE DID RESPOND IT WAS TOO LATE. LTT WAS ISSUED LEFT TURN 30 DEGS TO KEEP 5 NM--NOT ENOUGH OR TOO LATE.

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.