Narrative:

Bwi, dca, iad routed over hnk, psb due to WX. Altitude and mi in-trail due to ZNY (FL220 and 25 mi). All head on to normal flow of dny sector 24. Aircraft #1 eastbound vector at FL230. Aircraft #2 (WX re-route), wbound vector climbing to FL220 head on with aircraft #1. Aircraft #2 was initially cleared to FL230. Controller issued new altitude of FL220 about 25 mi away from aircraft #1. Traffic was passed as well. Aircraft #2 never acknowledged the new altitude of FL220. Aircraft #1 and aircraft #2 lost minimum separation about 35 mi southwest of alb. Both aircraft were turned to avoid collision. Aircraft #1 reacted to TCASII and climbed to FL237. Supplemental information from acn 626520: FL220 was issued to aircraft Y to go under aircraft X. Aircraft Y did not take the clearance. Supplemental information from acn 626732: we received a TA from TCASII for an aircraft above us at 1 O'clock position, descending. Next we received an RA to descend, which we did. The TCASII worked perfectly, just as advertised. RA guidance kept us clear of traffic in IFR conditions. The TA gave us excellent situational awareness and we were ready for the eventual resolution guidance.

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Original NASA ASRS Text

Title: RADAR ASSOCIATE CTLR AT ZBW DESCRIBES OPERROR AT FL230 LIKELY CAUSED BY READBACK ERROR DURING WX RE-RTE PROCS.

Narrative: BWI, DCA, IAD ROUTED OVER HNK, PSB DUE TO WX. ALT AND MI IN-TRAIL DUE TO ZNY (FL220 AND 25 MI). ALL HEAD ON TO NORMAL FLOW OF DNY SECTOR 24. ACFT #1 EBOUND VECTOR AT FL230. ACFT #2 (WX RE-RTE), WBOUND VECTOR CLBING TO FL220 HEAD ON WITH ACFT #1. ACFT #2 WAS INITIALLY CLRED TO FL230. CTLR ISSUED NEW ALT OF FL220 ABOUT 25 MI AWAY FROM ACFT #1. TFC WAS PASSED AS WELL. ACFT #2 NEVER ACKNOWLEDGED THE NEW ALT OF FL220. ACFT #1 AND ACFT #2 LOST MINIMUM SEPARATION ABOUT 35 MI SW OF ALB. BOTH ACFT WERE TURNED TO AVOID COLLISION. ACFT #1 REACTED TO TCASII AND CLBED TO FL237. SUPPLEMENTAL INFO FROM ACN 626520: FL220 WAS ISSUED TO ACFT Y TO GO UNDER ACFT X. ACFT Y DID NOT TAKE THE CLRNC. SUPPLEMENTAL INFO FROM ACN 626732: WE RECEIVED A TA FROM TCASII FOR AN ACFT ABOVE US AT 1 O'CLOCK POS, DSNDING. NEXT WE RECEIVED AN RA TO DSND, WHICH WE DID. THE TCASII WORKED PERFECTLY, JUST AS ADVERTISED. RA GUIDANCE KEPT US CLR OF TFC IN IFR CONDITIONS. THE TA GAVE US EXCELLENT SITUATIONAL AWARENESS AND WE WERE READY FOR THE EVENTUAL RESOLUTION GUIDANCE.

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.