Climbing large transport has near midair collision with small transport.

Attributes
ACN	90027
Time
Date	198807
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bae
State Reference	WI
Altitude	msl bound lower : 13200 msl bound upper : 13500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 10000 flight time type : 5000
ASRS Report	90027
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 0 vertical : 300
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

On assigned heading by chi center (090 degree) passing 13000' AGL my first officer (who was flying at the time) sighted a light twin yellow in color at 1 O'clock slightly above us on a northeast heading. I advised him to stop the climb. We contacted center at that time to advise him. He first told us of another contact which we said was not the subject aircraft. Then the controller stated that he had a 1200 squawk (at the position we said) at 13700'.

Original NASA ASRS Text

Title: CLIMBING LGT HAS NMAC WITH SMT.

Narrative: ON ASSIGNED HDG BY CHI CENTER (090 DEG) PASSING 13000' AGL MY F/O (WHO WAS FLYING AT THE TIME) SIGHTED A LIGHT TWIN YELLOW IN COLOR AT 1 O'CLOCK SLIGHTLY ABOVE US ON A NE HDG. I ADVISED HIM TO STOP THE CLIMB. WE CONTACTED CENTER AT THAT TIME TO ADVISE HIM. HE FIRST TOLD US OF ANOTHER CONTACT WHICH WE SAID WAS NOT THE SUBJECT ACFT. THEN THE CTLR STATED THAT HE HAD A 1200 SQUAWK (AT THE POSITION WE SAID) AT 13700'.

Data retrieved from NASA's ASRS site as of August 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.