Near midair collision with small aircraft aircraft in the TCA without clearance.

Attributes
ACN	84603
Time
Date	198803
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 2300 msl bound upper : 2600
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : ord tower : ewr
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent : approach landing : go around
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 13000 flight time type : 1000
ASRS Report	84603
Person 2
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : nmac
Independent Detector	other controllera other flight crewa
Resolutory Action	other other
Consequence	faa : reviewed incident with flight crew Other
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

Light plane with no communication to ord tower heading northeast across approach path from right to left. He was reported at 2600' and 2 mi at 2:30. We saw him, we were at 2600-2700' descending. At 2300' I started missed approach simultaneously with tower issuing us a missed approach (go around). We passed directly over the light aircraft (I figured 200'--approach said mode C showed 100'). Approach control and I agree that the missed approach was initiated at 200' vertical and 1 mi distance.

Original NASA ASRS Text

Title: NMAC WITH SMA ACFT IN THE TCA WITHOUT CLRNC.

Narrative: LIGHT PLANE WITH NO COM TO ORD TWR HDG NE ACROSS APCH PATH FROM RIGHT TO LEFT. HE WAS RPTED AT 2600' AND 2 MI AT 2:30. WE SAW HIM, WE WERE AT 2600-2700' DSNDING. AT 2300' I STARTED MISSED APCH SIMULTANEOUSLY WITH TWR ISSUING US A MISSED APCH (GO AROUND). WE PASSED DIRECTLY OVER THE LIGHT ACFT (I FIGURED 200'--APCH SAID MODE C SHOWED 100'). APCH CTL AND I AGREE THAT THE MISSED APCH WAS INITIATED AT 200' VERT AND 1 MI DISTANCE.

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.