Close proximity between air carrier medium large transport and unknown aircraft both in the TCA.

Attributes
ACN	198590
Time
Date	199201
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : iad
State Reference	VA
Altitude	msl bound lower : 9000 msl bound upper : 9600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iad tower : sea
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp
Experience	flight time last 90 days : 200 flight time total : 10000 flight time type : 4000
ASRS Report	198590
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	horizontal : 9000 vertical : 800
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Flight departed dulles airport. Captain was flying the aircraft 360 degree heading 8 NM north of dulles level 9000 ft MSL. Dulles departure control (frequency 125.05) directed us to turn right to 040 degree heading. As aircraft approached 040 degrees, departure control gave further turn to 120 degree heading. Meanwhile, I heard departure control giving TA's to another aircraft about our aircraft. Dulles never advised us about the position or direction of any other aircraft. As we rolled through 060 degree heading in 30 degree right bank to 120 degree heading assigned, the TCASII announced aurally 'traffic, traffic.' the TCASII scope indicated an aircraft approaching us from our 9 O'clock position 300 ft below and climbing (about 1 1/2 NM left of us). Then TCASII directed aural 'climb, climb' and vvi command of 2000 FPM. Captain immediately initiated a climb to about 9600 ft MSL where TCASII aurally stated 'clear of conflict' and he simultaneously advised dulles departure what we had done and why. He then flew aircraft back to 9000 ft. We never visually saw other aircraft. Dulles departure did not respond to our inquiries about the incident.

Original NASA ASRS Text

Title: CLOSE PROX BTWN ACR MLG AND UNKNOWN ACFT BOTH IN THE TCA.

Narrative: FLT DEPARTED DULLES ARPT. CAPT WAS FLYING THE ACFT 360 DEG HDG 8 NM N OF DULLES LEVEL 9000 FT MSL. DULLES DEP CTL (FREQ 125.05) DIRECTED US TO TURN R TO 040 DEG HDG. AS ACFT APCHED 040 DEGS, DEP CTL GAVE FURTHER TURN TO 120 DEG HDG. MEANWHILE, I HEARD DEP CTL GIVING TA'S TO ANOTHER ACFT ABOUT OUR ACFT. DULLES NEVER ADVISED US ABOUT THE POS OR DIRECTION OF ANY OTHER ACFT. AS WE ROLLED THROUGH 060 DEG HDG IN 30 DEG R BANK TO 120 DEG HDG ASSIGNED, THE TCASII ANNOUNCED AURALLY 'TFC, TFC.' THE TCASII SCOPE INDICATED AN ACFT APCHING US FROM OUR 9 O'CLOCK POS 300 FT BELOW AND CLBING (ABOUT 1 1/2 NM L OF US). THEN TCASII DIRECTED AURAL 'CLB, CLB' AND VVI COMMAND OF 2000 FPM. CAPT IMMEDIATELY INITIATED A CLB TO ABOUT 9600 FT MSL WHERE TCASII AURALLY STATED 'CLR OF CONFLICT' AND HE SIMULTANEOUSLY ADVISED DULLES DEP WHAT WE HAD DONE AND WHY. HE THEN FLEW ACFT BACK TO 9000 FT. WE NEVER VISUALLY SAW OTHER ACFT. DULLES DEP DID NOT RESPOND TO OUR INQUIRIES ABOUT THE INCIDENT.

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.