Near midair collision.

Attributes
ACN	268122
Time
Date	199403
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : dpa airport : arr
State Reference	IL
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	general aviation : corporate
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute : direct enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Cardinal 177/177RG
Operating Under FAR Part	Part 91
Flight Phase	cruise other cruise other
Route In Use	enroute : direct
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : first officer oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 6000
ASRS Report	268122
Person 2
Affiliation	Other
Function	flight crew : single pilot flight crew : captain
Qualification	pilot : cfi pilot : commercial pilot : instrument
Experience	flight time last 90 days : 100 flight time total : 1500 flight time type : 1000
ASRS Report	267586
Events
Anomaly	conflict : nmac non adherence : far non adherence : published procedure other anomaly other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 200
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

After receiving vectors around the north side of chicago, we were cleared direct to aurora, il, airport at 3000 ft MSL. At approximately 7 mi northwest of dupage airport, both crewmembers spotted a cessna cardinal right/G at our 4 O'clock relative position. Our IAS was 200 KTS, and the PF added power to avoid the cessna. (We were certain there was very little airspeed change.) I saw the cessna make a left turn away from us. We asked the controller if he had the traffic. The air traffic controller did not pick up the cessna until the cessna was over dupage airport as a primary target. We continued the flight to aurora airport with no further incident. Cause of problem: extensive vectoring at low altitudes around major terminal areas. Increases exposure to low level VFR aircraft. Prevent recurrence: altitude encoding xponders. Great help. We spotted all other traffic pointed out by ATC this morning. TCASII. Supplemental information from acn 267586: possible causes of this near collision are: absence of a secondary radar return from the cessna. He was within the 30 NM veil of the ord class B airspace.

Original NASA ASRS Text

Title: NMAC.

Narrative: AFTER RECEIVING VECTORS AROUND THE N SIDE OF CHICAGO, WE WERE CLRED DIRECT TO AURORA, IL, ARPT AT 3000 FT MSL. AT APPROX 7 MI NW OF DUPAGE ARPT, BOTH CREWMEMBERS SPOTTED A CESSNA CARDINAL R/G AT OUR 4 O'CLOCK RELATIVE POS. OUR IAS WAS 200 KTS, AND THE PF ADDED PWR TO AVOID THE CESSNA. (WE WERE CERTAIN THERE WAS VERY LITTLE AIRSPD CHANGE.) I SAW THE CESSNA MAKE A L TURN AWAY FROM US. WE ASKED THE CTLR IF HE HAD THE TFC. THE AIR TFC CTLR DID NOT PICK UP THE CESSNA UNTIL THE CESSNA WAS OVER DUPAGE ARPT AS A PRIMARY TARGET. WE CONTINUED THE FLT TO AURORA ARPT WITH NO FURTHER INCIDENT. CAUSE OF PROB: EXTENSIVE VECTORING AT LOW ALTS AROUND MAJOR TERMINAL AREAS. INCREASES EXPOSURE TO LOW LEVEL VFR ACFT. PREVENT RECURRENCE: ALT ENCODING XPONDERS. GREAT HELP. WE SPOTTED ALL OTHER TFC POINTED OUT BY ATC THIS MORNING. TCASII. SUPPLEMENTAL INFO FROM ACN 267586: POSSIBLE CAUSES OF THIS NEAR COLLISION ARE: ABSENCE OF A SECONDARY RADAR RETURN FROM THE CESSNA. HE WAS WITHIN THE 30 NM VEIL OF THE ORD CLASS B AIRSPACE.

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.