ZDC controller described a TCAS RA event when one air carrier was issued a climb to FL230; read back...

Attributes
ACN	920128
Time
Date	201011
Local Time Of Day	1801-2400
Place
Locale Reference	ZDC.ARTCC
State Reference	VA
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Aircraft 2
Make Model Name	Cessna Citation Sovereign (C680)
Operating Under FAR Part	Part 91
Flight Phase	Descent
Flight Plan	IFR
Person 1
Qualification	Air Traffic Control Fully Certified
Person 2
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 120 Flight Crew Total 12000 Flight Crew Type 4100
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Altitude Overshoot Deviation - Procedural Clearance

Narrative:

I climbed an A320 to FL230. During read back there was a loud horn sound from the flight deck. There was d-side training in progress; all 3 of us missed the bad read back to climb to FL260. Sector 18 controller stopped a C680 descent to FL260; teb arrival. When conflict alert activated; I began a transmission to instruct the A320 to maintain FL230; but changed to say altitude as I was trying to get situational awareness on the C680 altitude. Pilot responded we are in a RA descent; we were read back FL260. Recommendation; new rule for me; if there is excessive noise (alerters; horns etc.) I am going to verify instructions again. We also at the time had a report of unauthorized laser activity and the broadcasts for that were really increasing my workload. Must remain vigilant.

Original NASA ASRS Text

Title: ZDC Controller described a TCAS RA event when one Air Carrier was issued a climb to FL230; read back FL260; but was missed; the reporter alleging cockpit background noise on the frequency contributed to the read back error.

Narrative: I climbed an A320 to FL230. During read back there was a loud horn sound from the flight deck. There was D-Side training in progress; all 3 of us missed the bad read back to climb to FL260. Sector 18 Controller stopped a C680 descent to FL260; TEB arrival. When conflict alert activated; I began a transmission to instruct the A320 to maintain FL230; but changed to say altitude as I was trying to get situational awareness on the C680 altitude. Pilot responded we are in a RA descent; we were read back FL260. Recommendation; new rule for me; if there is excessive noise (alerters; horns etc.) I am going to verify instructions again. We also at the time had a report of unauthorized laser activity and the broadcasts for that were really increasing my workload. Must remain vigilant.

Data retrieved from NASA's ASRS site as of April 2012 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.

ZDC controller described a TCAS RA event when one air carrier was issued a climb to FL230; read back FL260; but was missed; the reporter alleging cockpit background noise on the frequency contributed to the read back error.