Narrative:

I was one of the pilots in a flight of 2 P51's, VFR at 11500 ft north of chicago ord, talking with ZAU. We were on the same frequency with aircraft Y who was level at 11000 ft. He was issued traffic (12 O'clock position at 11500 ft) and acknowledged. We saw him when he was several mi away, the controller issued traffic to aircraft Y again at 12 O'clock position, and 1 mi, he responded: that they had an RA, had descended, had us in sight and were climbing back to 11000 ft. I believe that all 3 parties involved in this situation acted in accordance with the far's. We were legal VFR at 11500 ft, aircraft Y was correct to follow the RA, the controller (I assume) was correct in issuing the traffic and not giving one of us a turn. However, as a B767 captain, familiar with TCASII, I'm certain that aircraft Y would have preferred a slight turn rather than responding to a TCASII alert! We would have been more than happy to take a turn for traffic. Better judgement on the part of the controller would have been to 'deconflict' the traffic, or at least offer a turn to one of us! We prefer not to cross the lake in a single engine aircraft of this type and appreciate the ability to transition the chicago airspace. The airspace could be shared with a higher measure of safety, if the controller were encouraged to offer a turn. I understand that traffic separation cannot be dictated with VFR traffic. But again, could they be encouraged to offer the turn to avoid a deviation by an airline aircraft when the VFR is willing to cooperate for increased safety?

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Original NASA ASRS Text

Title: PLT OF P51 FLT WITH ZAU AT 11500 FT NEAR ORD CAUSES TCASII RA WITH ACR AT 11000 FT, ATC ISSUED TFC.

Narrative: I WAS ONE OF THE PLTS IN A FLT OF 2 P51'S, VFR AT 11500 FT N OF CHICAGO ORD, TALKING WITH ZAU. WE WERE ON THE SAME FREQ WITH ACFT Y WHO WAS LEVEL AT 11000 FT. HE WAS ISSUED TFC (12 O'CLOCK POS AT 11500 FT) AND ACKNOWLEDGED. WE SAW HIM WHEN HE WAS SEVERAL MI AWAY, THE CTLR ISSUED TFC TO ACFT Y AGAIN AT 12 O'CLOCK POS, AND 1 MI, HE RESPONDED: THAT THEY HAD AN RA, HAD DSNDED, HAD US IN SIGHT AND WERE CLBING BACK TO 11000 FT. I BELIEVE THAT ALL 3 PARTIES INVOLVED IN THIS SIT ACTED IN ACCORDANCE WITH THE FAR'S. WE WERE LEGAL VFR AT 11500 FT, ACFT Y WAS CORRECT TO FOLLOW THE RA, THE CTLR (I ASSUME) WAS CORRECT IN ISSUING THE TFC AND NOT GIVING ONE OF US A TURN. HOWEVER, AS A B767 CAPT, FAMILIAR WITH TCASII, I'M CERTAIN THAT ACFT Y WOULD HAVE PREFERRED A SLIGHT TURN RATHER THAN RESPONDING TO A TCASII ALERT! WE WOULD HAVE BEEN MORE THAN HAPPY TO TAKE A TURN FOR TFC. BETTER JUDGEMENT ON THE PART OF THE CTLR WOULD HAVE BEEN TO 'DECONFLICT' THE TFC, OR AT LEAST OFFER A TURN TO ONE OF US! WE PREFER NOT TO CROSS THE LAKE IN A SINGLE ENG ACFT OF THIS TYPE AND APPRECIATE THE ABILITY TO TRANSITION THE CHICAGO AIRSPACE. THE AIRSPACE COULD BE SHARED WITH A HIGHER MEASURE OF SAFETY, IF THE CTLR WERE ENCOURAGED TO OFFER A TURN. I UNDERSTAND THAT TFC SEPARATION CANNOT BE DICTATED WITH VFR TFC. BUT AGAIN, COULD THEY BE ENCOURAGED TO OFFER THE TURN TO AVOID A DEV BY AN AIRLINE ACFT WHEN THE VFR IS WILLING TO COOPERATE FOR INCREASED SAFETY?

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.