Near midair collision.

Attributes
ACN	266949
Time
Date	199403
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : iad
State Reference	VA
Altitude	msl bound lower : 4000 msl bound upper : 4300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iad
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Cessna Aircraft Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 6500 flight time type : 3000
ASRS Report	266949
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : nmac non adherence : far other anomaly other other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	none taken : insufficient time
Consequence	faa : investigated
Miss Distance	horizontal : 400
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Arriving iad, end of 3 day trip. Located 15 south of dulles, 090 degrees assigned heading, descending through 4300 ft for 2000 ft. Received TCASII RA 'stop descent.' screen depicted target at our altitude, 12 O'clock. Leveled momentarily at 4000 ft and observed a red cessna pass off our left side, opposite direction (4000 ft MSL, heading 270 degrees). Distance estimated between 300-500 ft. Copilot told me later when he looked at TCASII, target was 300 ft below us. I was hand flying at the time. Approach informed us the floor of the TCA at that point was 2000 ft MSL. Cessna was transitioning at 4000 ft MSL, not talking to dulles. He eventually contacted dulles approach and later he was to contact dulles by phone. Note: approximately 2-3 mins before incident, dulles had cleared us for a visual approach. About a min later he canceled that clearance and put us on the 090 degree heading and gave us descent to 2000 ft. In essence, approach turned us directly towards the conflict (unintentionally). If we had continued with the visual approach, i.e., proceeding directly to the field, the cessna would not have been a conflict.

Original NASA ASRS Text

Title: NMAC.

Narrative: ARRIVING IAD, END OF 3 DAY TRIP. LOCATED 15 S OF DULLES, 090 DEGS ASSIGNED HDG, DSNDING THROUGH 4300 FT FOR 2000 FT. RECEIVED TCASII RA 'STOP DSCNT.' SCREEN DEPICTED TARGET AT OUR ALT, 12 O'CLOCK. LEVELED MOMENTARILY AT 4000 FT AND OBSERVED A RED CESSNA PASS OFF OUR L SIDE, OPPOSITE DIRECTION (4000 FT MSL, HDG 270 DEGS). DISTANCE ESTIMATED BTWN 300-500 FT. COPLT TOLD ME LATER WHEN HE LOOKED AT TCASII, TARGET WAS 300 FT BELOW US. I WAS HAND FLYING AT THE TIME. APCH INFORMED US THE FLOOR OF THE TCA AT THAT POINT WAS 2000 FT MSL. CESSNA WAS TRANSITIONING AT 4000 FT MSL, NOT TALKING TO DULLES. HE EVENTUALLY CONTACTED DULLES APCH AND LATER HE WAS TO CONTACT DULLES BY PHONE. NOTE: APPROX 2-3 MINS BEFORE INCIDENT, DULLES HAD CLRED US FOR A VISUAL APCH. ABOUT A MIN LATER HE CANCELED THAT CLRNC AND PUT US ON THE 090 DEG HDG AND GAVE US DSCNT TO 2000 FT. IN ESSENCE, APCH TURNED US DIRECTLY TOWARDS THE CONFLICT (UNINTENTIONALLY). IF WE HAD CONTINUED WITH THE VISUAL APCH, I.E., PROCEEDING DIRECTLY TO THE FIELD, THE CESSNA WOULD NOT HAVE BEEN A CONFLICT.

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.