Close proximity commuter light transport GA-small aircraft near jot VOR.

Attributes
ACN	116427
Time
Date	198907
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : jot airport : mdw
State Reference	IL
Altitude	msl bound lower : 4800 msl bound upper : 5000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	Light Transport, High Wing, 2 Turboprop Eng
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	climbout : intermediate altitude
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : flight engineer pilot : instrument pilot : cfi
Experience	flight time last 90 days : 200 flight time total : 1850 flight time type : 350
ASRS Report	116427
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 3200 flight time type : 1500
ASRS Report	116431
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 200 vertical : 100
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

Approximately 7 DME from jot VOR, ATC reported 'traffic at 11 O'clock, 5 mi, 4500', unverified.' we replied that we were looking but had negative contact. As we were both watching, ATC revised '11 O'clock, 4800', appears to be in a slow climb'. While still looking for the traffic, the captain made a smooth course deviation, about 45 degree to the right and approximately 100' descent. When the aircraft turned, I could see what appeared to be an small transport red and white, passing off our left. Within seconds, we were back on course and altitude. If not for a superb job by ATC and captain, we would have been involved in a disaster. I'm concerned about VFR traffic flying close to busy airspace at IFR altitudes on a hazy marginal day.

Original NASA ASRS Text

Title: CLOSE PROX COMMUTER LTT GA-SMA NEAR JOT VOR.

Narrative: APPROX 7 DME FROM JOT VOR, ATC REPORTED 'TFC AT 11 O'CLOCK, 5 MI, 4500', UNVERIFIED.' WE REPLIED THAT WE WERE LOOKING BUT HAD NEGATIVE CONTACT. AS WE WERE BOTH WATCHING, ATC REVISED '11 O'CLOCK, 4800', APPEARS TO BE IN A SLOW CLIMB'. WHILE STILL LOOKING FOR THE TFC, THE CAPT MADE A SMOOTH COURSE DEVIATION, ABOUT 45 DEG TO THE RIGHT AND APPROX 100' DSCNT. WHEN THE ACFT TURNED, I COULD SEE WHAT APPEARED TO BE AN SMT RED AND WHITE, PASSING OFF OUR LEFT. WITHIN SECONDS, WE WERE BACK ON COURSE AND ALT. IF NOT FOR A SUPERB JOB BY ATC AND CAPT, WE WOULD HAVE BEEN INVOLVED IN A DISASTER. I'M CONCERNED ABOUT VFR TFC FLYING CLOSE TO BUSY AIRSPACE AT IFR ALTS ON A HAZY MARGINAL DAY.

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.