Large transport has close proximity with second aircraft. TCASII RA, descends.

Attributes
ACN	207438
Time
Date	199204
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dca
State Reference	DC
Altitude	msl bound lower : 9700 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dca
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time total : 10000
ASRS Report	207438
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 4000 vertical : 600
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

ATC advised of VFR traffic at 1 O'clock 10500 ft. At approximately 20-25 mi east of dca initially obtained a TCASII TA, followed by a RA. Initially indicated 'monitor vertical speed climb' followed by a 'descend.' disconnected autoplt and initiated a slight descent to 9900 ft where RA terminated. Requested lower from ATC but they did not accommodate. They indicated the separation 'was good enough for them' thin cloud layer located immediately above the aircraft no visual contact obtained.

Original NASA ASRS Text

Title: LGT HAS CLOSE PROX WITH SECOND ACFT. TCASII RA, DSNDS.

Narrative: ATC ADVISED OF VFR TFC AT 1 O'CLOCK 10500 FT. AT APPROX 20-25 MI E OF DCA INITIALLY OBTAINED A TCASII TA, FOLLOWED BY A RA. INITIALLY INDICATED 'MONITOR VERT SPD CLB' FOLLOWED BY A 'DSND.' DISCONNECTED AUTOPLT AND INITIATED A SLIGHT DSCNT TO 9900 FT WHERE RA TERMINATED. REQUESTED LOWER FROM ATC BUT THEY DID NOT ACCOMMODATE. THEY INDICATED THE SEPARATION 'WAS GOOD ENOUGH FOR THEM' THIN CLOUD LAYER LOCATED IMMEDIATELY ABOVE THE ACFT NO VISUAL CONTACT OBTAINED.

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.