Near midair collision during a circling approach.

Attributes
ACN	291008
Time
Date	199410
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mdw
State Reference	IL
Altitude	agl bound lower : 900 agl bound upper : 900
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : mdw
Operator	common carrier : air taxi
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 135
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	None
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach other
Route In Use	approach : circling approach : visual
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 240 flight time total : 7000 flight time type : 2000
ASRS Report	291008
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : nmac non adherence : clearance other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 200 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Landing at mdw during good VMC WX. As usual running parallel operations. I think they were doing the ILS runway 31C circle runway 22L. I was on a straight-in final for runway 22R. The B-757 was on a left downwind for runway 22L. We were each given as traffic. I reported the 757 in sight -- he did not see us. There was a strong wind from the south and the 757 appeared like he was going to overshoot the final. I started widening out to the right and by this time was well north of the runway 22R centerline. The 757 rolled out of his turn and was now coming straight at me (he was approximately perpendicular to the runway centerline). He then advised he was deviating and climbing per TCASII alert. He continued climbing and went over the top of my aircraft. Both the controller and I were puzzled as to what the heck he was doing as there was no conflict until he created one. If he had rolled out on final as per his clearance it would have been routine traffic. My 'guess' is that he realized he was going to overshoot and climbed to avoid me. Regardless, I believe that TCASII information should be taken with a grain of salt when in the traffic area. It is dangerous to initiate avoidance when it isn't warranted. Especially when multiple runways are in use, which is the norm at most airports that TCASII equipped aircraft operate out of. He knew there was traffic for the parallel and that I had visual contact with him. I just hope that as he re- entered the traffic pattern he didn't tell the passenger that 'one of them little planes got in our way.' let's pay attention out there!

Original NASA ASRS Text

Title: NMAC DURING A CIRCLING APCH.

Narrative: LNDG AT MDW DURING GOOD VMC WX. AS USUAL RUNNING PARALLEL OPS. I THINK THEY WERE DOING THE ILS RWY 31C CIRCLE RWY 22L. I WAS ON A STRAIGHT-IN FINAL FOR RWY 22R. THE B-757 WAS ON A L DOWNWIND FOR RWY 22L. WE WERE EACH GIVEN AS TFC. I RPTED THE 757 IN SIGHT -- HE DID NOT SEE US. THERE WAS A STRONG WIND FROM THE S AND THE 757 APPEARED LIKE HE WAS GOING TO OVERSHOOT THE FINAL. I STARTED WIDENING OUT TO THE R AND BY THIS TIME WAS WELL N OF THE RWY 22R CTRLINE. THE 757 ROLLED OUT OF HIS TURN AND WAS NOW COMING STRAIGHT AT ME (HE WAS APPROX PERPENDICULAR TO THE RWY CTRLINE). HE THEN ADVISED HE WAS DEVIATING AND CLBING PER TCASII ALERT. HE CONTINUED CLBING AND WENT OVER THE TOP OF MY ACFT. BOTH THE CTLR AND I WERE PUZZLED AS TO WHAT THE HECK HE WAS DOING AS THERE WAS NO CONFLICT UNTIL HE CREATED ONE. IF HE HAD ROLLED OUT ON FINAL AS PER HIS CLRNC IT WOULD HAVE BEEN ROUTINE TFC. MY 'GUESS' IS THAT HE REALIZED HE WAS GOING TO OVERSHOOT AND CLBED TO AVOID ME. REGARDLESS, I BELIEVE THAT TCASII INFO SHOULD BE TAKEN WITH A GRAIN OF SALT WHEN IN THE TFC AREA. IT IS DANGEROUS TO INITIATE AVOIDANCE WHEN IT ISN'T WARRANTED. ESPECIALLY WHEN MULTIPLE RWYS ARE IN USE, WHICH IS THE NORM AT MOST ARPTS THAT TCASII EQUIPPED ACFT OPERATE OUT OF. HE KNEW THERE WAS TFC FOR THE PARALLEL AND THAT I HAD VISUAL CONTACT WITH HIM. I JUST HOPE THAT AS HE RE- ENTERED THE TFC PATTERN HE DIDN'T TELL THE PAX THAT 'ONE OF THEM LITTLE PLANES GOT IN OUR WAY.' LET'S PAY ATTN OUT THERE!

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.