Narrative:

While performing a standard aircraft check out, my student and I came alarmingly close to another aircraft. We were operating about 13 mi east of the pdk airport when we noticed the WX conditions to the west began to rapidly deteriorate. We had started to return when we ran into heavy rain that really brought the visibility down. I advised my student to make a 180 degree turn and head back to good VFR conditions. After we made it back into the better conditions, I called atl approach to get an IFR clearance back to pdk (our home base). The controller gave us a transponder code and advised us to remain in VFR conditions until he could work us in. While circling, the conditions forced us farther to the east and caused a need to descend to 2000 ft MSL. In this area, below about 2500 ft MSL (as I found out), the atl approach frequency can be heard, but they cannot hear you. I have since verified this with other pilots. Atl tried calling us numerous times. In order for them to hear us, we had to climb back up to at least 3000 ft MSL. We leveled here and tried contacting them again. The visibility began to worsen again, so once again, I asked my student to make a 180 degree turn and descend. While performing the turn we encountered a C-310 who was departure lzu airport flying on an instrument clearance. The conditions at the time of the occurrence were MVFR. We both used evasive maneuvers to avoid a conflict. He reported to ATC, in very upset voice, that he had come close to another aircraft. We had passed within 200 ft of each other. ATC then gave me a clearance and a vector for pdk. My continuation of VFR flight into deteriorating conditions and failure to look out my student's side window while turning left were the cause of this situation.

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Original NASA ASRS Text

Title: SMA ENCOUNTERS WX, TRIES TO PICK UP AN IFR CLRNC. HAS NMAC WITH DEPARTING SMT.

Narrative: WHILE PERFORMING A STANDARD ACFT CHK OUT, MY STUDENT AND I CAME ALARMINGLY CLOSE TO ANOTHER ACFT. WE WERE OPERATING ABOUT 13 MI E OF THE PDK ARPT WHEN WE NOTICED THE WX CONDITIONS TO THE W BEGAN TO RAPIDLY DETERIORATE. WE HAD STARTED TO RETURN WHEN WE RAN INTO HVY RAIN THAT REALLY BROUGHT THE VISIBILITY DOWN. I ADVISED MY STUDENT TO MAKE A 180 DEG TURN AND HEAD BACK TO GOOD VFR CONDITIONS. AFTER WE MADE IT BACK INTO THE BETTER CONDITIONS, I CALLED ATL APCH TO GET AN IFR CLRNC BACK TO PDK (OUR HOME BASE). THE CTLR GAVE US A XPONDER CODE AND ADVISED US TO REMAIN IN VFR CONDITIONS UNTIL HE COULD WORK US IN. WHILE CIRCLING, THE CONDITIONS FORCED US FARTHER TO THE E AND CAUSED A NEED TO DSND TO 2000 FT MSL. IN THIS AREA, BELOW ABOUT 2500 FT MSL (AS I FOUND OUT), THE ATL APCH FREQ CAN BE HEARD, BUT THEY CANNOT HEAR YOU. I HAVE SINCE VERIFIED THIS WITH OTHER PLTS. ATL TRIED CALLING US NUMEROUS TIMES. IN ORDER FOR THEM TO HEAR US, WE HAD TO CLB BACK UP TO AT LEAST 3000 FT MSL. WE LEVELED HERE AND TRIED CONTACTING THEM AGAIN. THE VISIBILITY BEGAN TO WORSEN AGAIN, SO ONCE AGAIN, I ASKED MY STUDENT TO MAKE A 180 DEG TURN AND DSND. WHILE PERFORMING THE TURN WE ENCOUNTERED A C-310 WHO WAS DEP LZU ARPT FLYING ON AN INST CLRNC. THE CONDITIONS AT THE TIME OF THE OCCURRENCE WERE MVFR. WE BOTH USED EVASIVE MANEUVERS TO AVOID A CONFLICT. HE RPTED TO ATC, IN VERY UPSET VOICE, THAT HE HAD COME CLOSE TO ANOTHER ACFT. WE HAD PASSED WITHIN 200 FT OF EACH OTHER. ATC THEN GAVE ME A CLRNC AND A VECTOR FOR PDK. MY CONTINUATION OF VFR FLT INTO DETERIORATING CONDITIONS AND FAILURE TO LOOK OUT MY STUDENT'S SIDE WINDOW WHILE TURNING L WERE THE CAUSE OF THIS SIT.

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.