Narrative:

VFR flight from hto to phl. We were told to descend out of 8500 ft for 6500 ft and turn to a heading of 180 degrees. Shortly after, we were told to do some '360's' due to delays at destination. 1/2 way through a turn, I spotted a jet (probably a B737) coming towards me, and what appeared to be at the same altitude. I instinctively executed a descending turn to avoid. After the conflict, I returned to 6500 ft (I descended to 6200 ft during the escape maneuver), phl queried about our descent. Our response was to avoid traffic, and we were returning to 6500 ft. In my best judgement, we had never entered class B airspace, as it was the PNF's job to ensure, who was another captain-qualified crew member. Phl informed us at this point that all the holding traffic was below us. I executed an escape maneuver to avoid what I perceived an emergency. This could have been avoided if phl had told us before hand that traffic was holding below us, or if we had TCASII installed. Either of these would have changed my perception of the perceived emergency. I was also confused when phl told us to remain clear of the class B airspace, with little notice, then subsequently assigned us a heading and altitude to maintain. It was unclr at this point whether we were getting TA's. Supplemental information from acn 514174: trying to avoid difficulty operating IFR near new york terminal area (low altitudes, long rtes) captain and I decided to file VFR for part 135 flight. No problems cruising at 14500 ft on direct route, new york even gave VFR radar advisories without complaint. New york terminated service near rbv VOR (next controller wouldn't take VFR traffic). Contacted phl approach 30 mi out, told to remain clear of class B. Aircraft leveled at 7500 ft (above 7000 ft limit) and planned to circle just outside lateral limits. Phl issued squawk, heading, and altitude that would take us into cloud. Captain began maneuvering to attempt compliance with ATC. In remaining clear of cloud, we penetrated class B airspace(?). As we turned away from class B airspace we were instructed to do 360's and maintain 6500 ft. As we completed the first 180 degrees of turn, captain spotted jetliner which appeared to be in a descending turn toward us. When asked by ATC about deviation from 'assigned' altitude (outside class B airspace) we responded we were avoiding collision. We were then told (for the first time) that all traffic would be vectored at 6000 ft. We returned to 6500 ft and had no further difficulty maintaining VFR or complying with ATC. Captain and I were fatigued.

Google
 

Original NASA ASRS Text

Title: PART 135 BE9L FLC MAKE EVASIVE MANEUVER TO INCREASE SEPARATION WITH B737 AND POSSIBLY PENETRATE PHL CLASS B AIRSPACE.

Narrative: VFR FLT FROM HTO TO PHL. WE WERE TOLD TO DSND OUT OF 8500 FT FOR 6500 FT AND TURN TO A HDG OF 180 DEGS. SHORTLY AFTER, WE WERE TOLD TO DO SOME '360'S' DUE TO DELAYS AT DEST. 1/2 WAY THROUGH A TURN, I SPOTTED A JET (PROBABLY A B737) COMING TOWARDS ME, AND WHAT APPEARED TO BE AT THE SAME ALT. I INSTINCTIVELY EXECUTED A DSNDING TURN TO AVOID. AFTER THE CONFLICT, I RETURNED TO 6500 FT (I DSNDED TO 6200 FT DURING THE ESCAPE MANEUVER), PHL QUERIED ABOUT OUR DSCNT. OUR RESPONSE WAS TO AVOID TFC, AND WE WERE RETURNING TO 6500 FT. IN MY BEST JUDGEMENT, WE HAD NEVER ENTERED CLASS B AIRSPACE, AS IT WAS THE PNF'S JOB TO ENSURE, WHO WAS ANOTHER CAPT-QUALIFIED CREW MEMBER. PHL INFORMED US AT THIS POINT THAT ALL THE HOLDING TFC WAS BELOW US. I EXECUTED AN ESCAPE MANEUVER TO AVOID WHAT I PERCEIVED AN EMER. THIS COULD HAVE BEEN AVOIDED IF PHL HAD TOLD US BEFORE HAND THAT TFC WAS HOLDING BELOW US, OR IF WE HAD TCASII INSTALLED. EITHER OF THESE WOULD HAVE CHANGED MY PERCEPTION OF THE PERCEIVED EMER. I WAS ALSO CONFUSED WHEN PHL TOLD US TO REMAIN CLR OF THE CLASS B AIRSPACE, WITH LITTLE NOTICE, THEN SUBSEQUENTLY ASSIGNED US A HDG AND ALT TO MAINTAIN. IT WAS UNCLR AT THIS POINT WHETHER WE WERE GETTING TA'S. SUPPLEMENTAL INFO FROM ACN 514174: TRYING TO AVOID DIFFICULTY OPERATING IFR NEAR NEW YORK TERMINAL AREA (LOW ALTS, LONG RTES) CAPT AND I DECIDED TO FILE VFR FOR PART 135 FLT. NO PROBS CRUISING AT 14500 FT ON DIRECT RTE, NEW YORK EVEN GAVE VFR RADAR ADVISORIES WITHOUT COMPLAINT. NEW YORK TERMINATED SVC NEAR RBV VOR (NEXT CTLR WOULDN'T TAKE VFR TFC). CONTACTED PHL APCH 30 MI OUT, TOLD TO REMAIN CLR OF CLASS B. ACFT LEVELED AT 7500 FT (ABOVE 7000 FT LIMIT) AND PLANNED TO CIRCLE JUST OUTSIDE LATERAL LIMITS. PHL ISSUED SQUAWK, HDG, AND ALT THAT WOULD TAKE US INTO CLOUD. CAPT BEGAN MANEUVERING TO ATTEMPT COMPLIANCE WITH ATC. IN REMAINING CLR OF CLOUD, WE PENETRATED CLASS B AIRSPACE(?). AS WE TURNED AWAY FROM CLASS B AIRSPACE WE WERE INSTRUCTED TO DO 360'S AND MAINTAIN 6500 FT. AS WE COMPLETED THE FIRST 180 DEGS OF TURN, CAPT SPOTTED JETLINER WHICH APPEARED TO BE IN A DSNDING TURN TOWARD US. WHEN ASKED BY ATC ABOUT DEV FROM 'ASSIGNED' ALT (OUTSIDE CLASS B AIRSPACE) WE RESPONDED WE WERE AVOIDING COLLISION. WE WERE THEN TOLD (FOR THE FIRST TIME) THAT ALL TFC WOULD BE VECTORED AT 6000 FT. WE RETURNED TO 6500 FT AND HAD NO FURTHER DIFFICULTY MAINTAINING VFR OR COMPLYING WITH ATC. CAPT AND I WERE FATIGUED.

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.