Narrative:

My aircraft (a C172) was on a flight from ZZZ1 to ZZZ2. The flight was on an IFR flight plan and served a dual purpose as an instrument training cross country flight. A safety pilot, an infant passenger, and an adult passenger were on board. Cruising altitude was 5000 ft and conditions were mixed and IMC when I was xferred over to approach control upon entering the southeast quadrant of class B airspace. I was given a vector and instruction to descend and maintain 4000 ft. Upon initiating the descent, I entered IMC. Level at 4000 ft, the approach controller advised I had VFR traffic at 11-12 O'clock position and 2 mi at 4000 ft. I advised the controller I was IMC. No acknowledgement was received, and no instruction was heard for any other aircraft to deviate. I am unsure if the controller was in radio contact or performing flight following for the other traffic. Approximately 20 seconds passed when I exited IMC into mvmc and observed a high wing cessna aircraft at near my same altitude, on a direct collision course, and less than 500 ft horizontal distance. I took immediate evasive action by banking to the right. The pilot of the other aircraft evasively banked in the opposite direction. We passed in opposite directions less than 250 ft apart and at the near same altitude. Disturbed by the lack of separation on an IFR flight plan and in intermittent IMC, I called approach with the intent of asking what degree of separation I could expect since I was in and out of IMC. The approach controller responded 'the traffic is no longer a factor.' it is my opinion that had we not exited IMC when we did, a midair collision most likely would have occurred. Having the safety pilot on board (I was not under a hood since we were in actual IMC) would not have assisted in avoiding the collision in my opinion. The patient and parent were delivered to ZZZ2 for their physician appointment. My safety pilot and I awaited their return for the trip back to ZZZ1. We departed under an IFR flight plan and landed back at ZZZ1 at approximately XA30 after an uneventful flight. While I was placing my airplane back into my hangar at about XF00, a man unknown to me came to my hangar and asked, 'were you in ZZZ2 a few hours ago?' I replied that I was and he said, 'I thought your airplane looked familiar. We got kind of close in the clouds.' I was surprised to find that this individual (mr X, a student pilot) indicated that he was plting the airplane that almost collided with me hundreds of mi away from my base airport. Through the brief conversation, it appeared that he was flying VFR avoiding WX (scud running) to get our of the area.

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Original NASA ASRS Text

Title: C172 ON AN IFR FLT PLAN HAS AN NMAC WITH OPPOSITE DIRECTION, SAME ALT LIGHT ACFT WHICH HAD BEEN CALLED OUT AS VFR TFC AT 2 MI BY A80 APCH CTLR WHILE C172 WAS IN IMC.

Narrative: MY ACFT (A C172) WAS ON A FLT FROM ZZZ1 TO ZZZ2. THE FLT WAS ON AN IFR FLT PLAN AND SERVED A DUAL PURPOSE AS AN INST TRAINING XCOUNTRY FLT. A SAFETY PLT, AN INFANT PAX, AND AN ADULT PAX WERE ON BOARD. CRUISING ALT WAS 5000 FT AND CONDITIONS WERE MIXED AND IMC WHEN I WAS XFERRED OVER TO APCH CTL UPON ENTERING THE SE QUADRANT OF CLASS B AIRSPACE. I WAS GIVEN A VECTOR AND INSTRUCTION TO DSND AND MAINTAIN 4000 FT. UPON INITIATING THE DSCNT, I ENTERED IMC. LEVEL AT 4000 FT, THE APCH CTLR ADVISED I HAD VFR TFC AT 11-12 O'CLOCK POS AND 2 MI AT 4000 FT. I ADVISED THE CTLR I WAS IMC. NO ACKNOWLEDGEMENT WAS RECEIVED, AND NO INSTRUCTION WAS HEARD FOR ANY OTHER ACFT TO DEVIATE. I AM UNSURE IF THE CTLR WAS IN RADIO CONTACT OR PERFORMING FLT FOLLOWING FOR THE OTHER TFC. APPROX 20 SECONDS PASSED WHEN I EXITED IMC INTO MVMC AND OBSERVED A HIGH WING CESSNA ACFT AT NEAR MY SAME ALT, ON A DIRECT COLLISION COURSE, AND LESS THAN 500 FT HORIZ DISTANCE. I TOOK IMMEDIATE EVASIVE ACTION BY BANKING TO THE R. THE PLT OF THE OTHER ACFT EVASIVELY BANKED IN THE OPPOSITE DIRECTION. WE PASSED IN OPPOSITE DIRECTIONS LESS THAN 250 FT APART AND AT THE NEAR SAME ALT. DISTURBED BY THE LACK OF SEPARATION ON AN IFR FLT PLAN AND IN INTERMITTENT IMC, I CALLED APCH WITH THE INTENT OF ASKING WHAT DEGREE OF SEPARATION I COULD EXPECT SINCE I WAS IN AND OUT OF IMC. THE APCH CTLR RESPONDED 'THE TFC IS NO LONGER A FACTOR.' IT IS MY OPINION THAT HAD WE NOT EXITED IMC WHEN WE DID, A MIDAIR COLLISION MOST LIKELY WOULD HAVE OCCURRED. HAVING THE SAFETY PLT ON BOARD (I WAS NOT UNDER A HOOD SINCE WE WERE IN ACTUAL IMC) WOULD NOT HAVE ASSISTED IN AVOIDING THE COLLISION IN MY OPINION. THE PATIENT AND PARENT WERE DELIVERED TO ZZZ2 FOR THEIR PHYSICIAN APPOINTMENT. MY SAFETY PLT AND I AWAITED THEIR RETURN FOR THE TRIP BACK TO ZZZ1. WE DEPARTED UNDER AN IFR FLT PLAN AND LANDED BACK AT ZZZ1 AT APPROX XA30 AFTER AN UNEVENTFUL FLT. WHILE I WAS PLACING MY AIRPLANE BACK INTO MY HANGAR AT ABOUT XF00, A MAN UNKNOWN TO ME CAME TO MY HANGAR AND ASKED, 'WERE YOU IN ZZZ2 A FEW HRS AGO?' I REPLIED THAT I WAS AND HE SAID, 'I THOUGHT YOUR AIRPLANE LOOKED FAMILIAR. WE GOT KIND OF CLOSE IN THE CLOUDS.' I WAS SURPRISED TO FIND THAT THIS INDIVIDUAL (MR X, A STUDENT PLT) INDICATED THAT HE WAS PLTING THE AIRPLANE THAT ALMOST COLLIDED WITH ME HUNDREDS OF MI AWAY FROM MY BASE ARPT. THROUGH THE BRIEF CONVERSATION, IT APPEARED THAT HE WAS FLYING VFR AVOIDING WX (SCUD RUNNING) TO GET OUR OF THE AREA.

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.