Reporter had to alter descent to respond to TCASII RA.

Attributes
ACN	317756
Time
Date	199510
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ric
State Reference	VA
Altitude	msl bound lower : 16700 msl bound upper : 17000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other other
Route In Use	arrival star : star
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	other : unknown
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	317756
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : airborne less severe
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance flight crew : took evasive action other
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 1700 vertical : 400
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

On arrival to bwi from the south, was given a 15000 ft crossing restr at sabbi. The restr was given late for a normal descent rate, so we had the nose down and speed up to make it. During the descent, I noticed traffic pop up on the TCASII and advised the first officer who was flying. We started to slow our descent rate and were handed off from frequency 127.75 to 128.35. TCASII announced 'traffic traffic' followed shortly by 'climb, climb now.' because we were focused on the conflict, I didn't check in right away but soon after we switched, ATC was calling us and advised us to maintain 17000 ft. We were already in a climb after bottoming out at 16700 ft. The VFR traffic at 16500 ft passed off the left nose. Lateral separation about 1700 ft vertical 400 ft when we passed.

Original NASA ASRS Text

Title: RPTR HAD TO ALTER DSCNT TO RESPOND TO TCASII RA.

Narrative: ON ARR TO BWI FROM THE S, WAS GIVEN A 15000 FT XING RESTR AT SABBI. THE RESTR WAS GIVEN LATE FOR A NORMAL DSCNT RATE, SO WE HAD THE NOSE DOWN AND SPD UP TO MAKE IT. DURING THE DSCNT, I NOTICED TFC POP UP ON THE TCASII AND ADVISED THE FO WHO WAS FLYING. WE STARTED TO SLOW OUR DSCNT RATE AND WERE HANDED OFF FROM FREQ 127.75 TO 128.35. TCASII ANNOUNCED 'TFC TFC' FOLLOWED SHORTLY BY 'CLB, CLB NOW.' BECAUSE WE WERE FOCUSED ON THE CONFLICT, I DIDN'T CHK IN RIGHT AWAY BUT SOON AFTER WE SWITCHED, ATC WAS CALLING US AND ADVISED US TO MAINTAIN 17000 FT. WE WERE ALREADY IN A CLB AFTER BOTTOMING OUT AT 16700 FT. THE VFR TFC AT 16500 FT PASSED OFF THE L NOSE. LATERAL SEPARATION ABOUT 1700 FT VERT 400 FT WHEN WE PASSED.

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.