Narrative:

I was flying the airplane in mcguire approach's airspace. We were navigating eastbound on the pne 100 degree right at the flight planned altitude of 5000' MSL. We were working approach on 120.25 MHZ. There was an small transport on the frequency IFR. He cancelled and climbed to 4500' MSL and stayed on for VFR advisory service. Shortly thereafter the controller issued us a descent to 4000 MSL. I began the descent, with a rate of 300 FPM since our aircraft is unpressurized. We had no idea the small transport would be a factor since we didn't know where he was. All we knew was that he was wbound at 4500 MSL. Also, it is normal for mcguire approach to give us that descent. They usually have us down to 3000' MSL for the handoff to new york, but occasionally they hand us off at 4000 MSL. Sometimes we get a single descent from 5000 MSL to 3000 MSL, minimizing the amount of time we spend at the wbound altitude. Other times, as in this case, mcguire steps us down from 5000 to 4000, and then from 4000 MSL to 3000 MSL. The facts that this descent is normal and that we didn't consider the small transport a factor probably contributed to this incident since southeast had no reason to be on alert for the aircraft. Mcguire approach at no time issued a traffic advisory to us or the small transport. He passed low, off our right side in an evasive left turn. His approach was from opposite direction at 12:00-12:30. Closure rate would have been about 400 KTS. Although good VMC prevailed and both myself and the captain were scanning for traffic, neither of us saw him until it would have been literally too late to avoid him. Had the small transport pilot not turned to avoid us I feel a collision would have occurred. It is probable that my crew, the small transport pilot, and the controller are all liable for contributing, but I feel the bulk of the problem rests with approach control since we were IFR and guaranteed separation.

Related reports:

Google
 

Original NASA ASRS Text

Title: CLOSE PROX COMMUTER LTT-GA SMT NORTHEAST OF WRI.

Narrative: I WAS FLYING THE AIRPLANE IN MCGUIRE APCH'S AIRSPACE. WE WERE NAVIGATING EBND ON THE PNE 100 DEG R AT THE FLT PLANNED ALT OF 5000' MSL. WE WERE WORKING APCH ON 120.25 MHZ. THERE WAS AN SMT ON THE FREQ IFR. HE CANCELLED AND CLIMBED TO 4500' MSL AND STAYED ON FOR VFR ADVISORY SERVICE. SHORTLY THEREAFTER THE CTLR ISSUED US A DSCNT TO 4000 MSL. I BEGAN THE DSCNT, WITH A RATE OF 300 FPM SINCE OUR ACFT IS UNPRESSURIZED. WE HAD NO IDEA THE SMT WOULD BE A FACTOR SINCE WE DIDN'T KNOW WHERE HE WAS. ALL WE KNEW WAS THAT HE WAS WBOUND AT 4500 MSL. ALSO, IT IS NORMAL FOR MCGUIRE APCH TO GIVE US THAT DSCNT. THEY USUALLY HAVE US DOWN TO 3000' MSL FOR THE HANDOFF TO NEW YORK, BUT OCCASIONALLY THEY HAND US OFF AT 4000 MSL. SOMETIMES WE GET A SINGLE DSCNT FROM 5000 MSL TO 3000 MSL, MINIMIZING THE AMOUNT OF TIME WE SPEND AT THE WBOUND ALT. OTHER TIMES, AS IN THIS CASE, MCGUIRE STEPS US DOWN FROM 5000 TO 4000, AND THEN FROM 4000 MSL TO 3000 MSL. THE FACTS THAT THIS DSCNT IS NORMAL AND THAT WE DIDN'T CONSIDER THE SMT A FACTOR PROBABLY CONTRIBUTED TO THIS INCIDENT SINCE SE HAD NO REASON TO BE ON ALERT FOR THE ACFT. MCGUIRE APCH AT NO TIME ISSUED A TFC ADVISORY TO US OR THE SMT. HE PASSED LOW, OFF OUR RIGHT SIDE IN AN EVASIVE LEFT TURN. HIS APCH WAS FROM OPPOSITE DIRECTION AT 12:00-12:30. CLOSURE RATE WOULD HAVE BEEN ABOUT 400 KTS. ALTHOUGH GOOD VMC PREVAILED AND BOTH MYSELF AND THE CAPT WERE SCANNING FOR TFC, NEITHER OF US SAW HIM UNTIL IT WOULD HAVE BEEN LITERALLY TOO LATE TO AVOID HIM. HAD THE SMT PLT NOT TURNED TO AVOID US I FEEL A COLLISION WOULD HAVE OCCURRED. IT IS PROBABLE THAT MY CREW, THE SMT PLT, AND THE CTLR ARE ALL LIABLE FOR CONTRIBUTING, BUT I FEEL THE BULK OF THE PROBLEM RESTS WITH APCH CTL SINCE WE WERE IFR AND GUARANTEED SEPARATION.

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.