A C182 PVT PLT RPT ON THE UNSATISFACTORY TFC SEPARATION PROCS THAT WERE ATTEMPTED BY N90 APCH CTLR AT HPN; NY.

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I WAS TRAVELING ON AN INST FLT PLAN FROM DCA TO HPN. PRIOR TO REACHING BREZY; NY APCH CLRED ME 'DIRECT WHITE PLAINS.' I WAS CONCERNED THAT THE DIRECT HPN CLRNC WAS SETTING UP FOR A VISUAL APCH AND LNDG THAT MIGHT NOT BE FULLY OR TRULY VISUAL AS I WAS STILL ABOVE A VERY THICK GND LAYER WITH ONLY OCCASIONAL GND CONTACT. I REQUESTED THE ILS RWY 16 AND NEW YORK INSTRUCTED ME TO DSND AND MAINTAIN 2000 FT AND VECTORED ME TO THE N TO INTERCEPT. AFTER 1 MORE VECTOR; NEW YORK CLRED ME FOR THE ILS RWY 16 APCH. I INTERCEPTED AND TURNED INBOUND WITH GPS INDICATING ABOUT 14 DME FROM HPN. NEW YORK DID NOT HAND ME OFF TO TWR AS NEW YORK WAS HANDLING 2 ADDITIONAL INBOUNDS ON THE ILS RWY 16; AN ACR FLT AND A BIZJET. NEW YORK THEN INSTRUCTED THE ACR FLT; WHICH HAD BEEN CLRED ON THE ILS RWY 16 TO OVERTAKE ME ON THE APCH. I WAS STILL DOING THE MENTAL MATH TO ESTIMATE THE POINT AT WHICH AN APPROX 160 KT ACFT WOULD OVERTAKE MY 100 KT APCH SPD AND IF I WOULD HAVE INTERCEPTED GS YET WHEN THE ACR FLT QUESTIONED THE NEW YORK INSTRUCTION TO 'OVERTAKE THE CESSNA ON APCH.' I WAS QUITE RELIEVED TO HEAR THE ACR FLT QUESTION THE CTLR'S INSTRUCTION. NEW YORK ASKED ACR IF HE WANTED THE CESSNA TO DO A 360 DEG TURN; TO WHICH ACR REPLIED THAT THAT WAS NEW YORK'S DECISION AND FUNCTION. NEW YORK THEN INSTRUCTED ME TO DO A L 360 TO ALLOW BOTH JETS TO PASS AND THEN REINTERCEPT THE ILS. I BEGAN THE 360 DEG TURN AND HAD VISUAL CONTACT WITH THE 2 INBOUND JETS DURING THE LAST 270 DEGS OF THE TURN. NEW YORK HANDED THE 2 JETS OFF TO TWR AND CLRED ME TO REINTERCEPT. I RE-ESTABLISHED ON THE ILS; WAS HANDED OFF TO TWR AND LANDED WITHOUT INCIDENT. MY CONCERNS ABOUT THIS CTR ON: 1) ESTABLISHING AND MAINTAINING VERT SEPARATION WITH AN ACFT THAT I COULD NOT SEE DUE TO ITS POS BEHIND AND ABOVE ME. 2) ASSUMING NON COLLISION VERT SEPARATION I ESTIMATE THAT I WOULD HAVE BEEN LESS THAN 500 FT BELOW THE ACR JET FLT FLYING THE SAME LOC CTRLINE WHICH WOULD EXPOSE MY C182 TO POTENTIALLY SEVERE WAKE TURB. 3) THE EXPECTATION DEMONSTRATED BY NEW YORK APCH LOOKING FOR ACFT IN IFR FLT TO PROCEED VISUALLY WHILE ON AN INST APCH. 4) THE POTENTIAL FOR LIMITED VISIBILITY IN CLOUDS/FOG WITHIN A FEW MI OF MY POS. 5) MY RELUCTANCE TO QUESTION AN ATC INSTRUCTION DESPITE PALPABLE DISCOMFORT. IN TERMS OF CORRECTIVE ACTION: 1) I NEED TO MORE READILY QUESTION AN ATC INSTRUCTION WITH WHICH I AM NOT COMFORTABLE AS PIC. 2) ATC NEEDS TO THINK TWICE BEFORE INSTRUCTIONS TO OVERTAKE ON APCH ARE GIVEN TO A LARGE ACFT OVERTAKING A SMALLER ONE DURING AN ILS APCH WHEN ONE IS ON GS AND THE OTHER IS RAPIDLY APCHING IT. 3) COMMENDATION FOR THE ACR CREW'S QUESTIONING OF THE INSTRUCTIONS THEREBY HELPING TO ENSURE A SAFE APCH AND LNDG FOR ALL 3 ACFT.