Narrative:

We were inbound to teb in our astra spx (G-100). We had flown the wilkes-barre 3 arrival to the VOR/DME-a approach to runway 19. At about XA00; after being cleared direct wanes; we received a clearance which I understood as 'wanes at 3000 ft; clifo at 2000 ft; cleared for the VOR/DME-a approach.' I have flown this approach many times and this the customary clearance on this approach at that point. The first officer acknowledged the clearance; I believe; as 'cleared for VOR/DME-a approach' without the altitude assignment. He did not read back the entire clearance. We intercepted the approach course a bit inside of wanes; joined the approach course and descended to 2500 per the approach. A few seconds after leveling off at 2500 ft; the controller called and said words to the effect that we should be at 3000 ft. We responded that we must have misunderstood the clearance. He said 'ok' or something of the sort and did not tell us to change altitude. We continued at 2500 ft and shortly arrived at jaymo. Either shortly before jaymo or shortly after jaymo; I noticed traffic on the TCASII above and to our left. The controller may have called the traffic; but I was busy looking for the many VFR airplanes that I had heard on the radio and the call; if made; didn't register on me. I looked out the window and saw a single engine aircraft approaching from the left perpendicular to our flight path and about 100 ft above us. I could see the aircraft very clearly and determined that it would pass above and behind us. The TCASII may have given a 'dive' command; but; if so; it didn't register on me. I took no evasive action because it was clear to me that we were not on a collision course. The aircraft passed about 100 ft above us and behind us by a distance I could not determine from the cockpit. We continued the approach and landed normally at teb. After thinking about the situation; I believe it possible that the controller's clearance was 'jaymo at 3000 ft; cleared for the VOR/DME-a approach' (a clearance not consistent with the published approach) although this is not what we read back. The situation would have been avoided had we asked the controller to repeat the clearance and had we read it back fully for confirmation.

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Original NASA ASRS Text

Title: A G100 PLT DOES NOT FOLLOW APCH CLRNC ALT RESTRS ON TEB VOR-DME 'A' AND EXPERIENCES A NEAR MISS.

Narrative: WE WERE INBOUND TO TEB IN OUR ASTRA SPX (G-100). WE HAD FLOWN THE WILKES-BARRE 3 ARR TO THE VOR/DME-A APCH TO RWY 19. AT ABOUT XA00; AFTER BEING CLRED DIRECT WANES; WE RECEIVED A CLRNC WHICH I UNDERSTOOD AS 'WANES AT 3000 FT; CLIFO AT 2000 FT; CLRED FOR THE VOR/DME-A APCH.' I HAVE FLOWN THIS APCH MANY TIMES AND THIS THE CUSTOMARY CLRNC ON THIS APCH AT THAT POINT. THE FO ACKNOWLEDGED THE CLRNC; I BELIEVE; AS 'CLRED FOR VOR/DME-A APCH' WITHOUT THE ALT ASSIGNMENT. HE DID NOT READ BACK THE ENTIRE CLRNC. WE INTERCEPTED THE APCH COURSE A BIT INSIDE OF WANES; JOINED THE APCH COURSE AND DSNDED TO 2500 PER THE APCH. A FEW SECONDS AFTER LEVELING OFF AT 2500 FT; THE CTLR CALLED AND SAID WORDS TO THE EFFECT THAT WE SHOULD BE AT 3000 FT. WE RESPONDED THAT WE MUST HAVE MISUNDERSTOOD THE CLRNC. HE SAID 'OK' OR SOMETHING OF THE SORT AND DID NOT TELL US TO CHANGE ALT. WE CONTINUED AT 2500 FT AND SHORTLY ARRIVED AT JAYMO. EITHER SHORTLY BEFORE JAYMO OR SHORTLY AFTER JAYMO; I NOTICED TFC ON THE TCASII ABOVE AND TO OUR L. THE CTLR MAY HAVE CALLED THE TFC; BUT I WAS BUSY LOOKING FOR THE MANY VFR AIRPLANES THAT I HAD HEARD ON THE RADIO AND THE CALL; IF MADE; DIDN'T REGISTER ON ME. I LOOKED OUT THE WINDOW AND SAW A SINGLE ENG ACFT APCHING FROM THE L PERPENDICULAR TO OUR FLT PATH AND ABOUT 100 FT ABOVE US. I COULD SEE THE ACFT VERY CLRLY AND DETERMINED THAT IT WOULD PASS ABOVE AND BEHIND US. THE TCASII MAY HAVE GIVEN A 'DIVE' COMMAND; BUT; IF SO; IT DIDN'T REGISTER ON ME. I TOOK NO EVASIVE ACTION BECAUSE IT WAS CLR TO ME THAT WE WERE NOT ON A COLLISION COURSE. THE ACFT PASSED ABOUT 100 FT ABOVE US AND BEHIND US BY A DISTANCE I COULD NOT DETERMINE FROM THE COCKPIT. WE CONTINUED THE APCH AND LANDED NORMALLY AT TEB. AFTER THINKING ABOUT THE SIT; I BELIEVE IT POSSIBLE THAT THE CTLR'S CLRNC WAS 'JAYMO AT 3000 FT; CLRED FOR THE VOR/DME-A APCH' (A CLRNC NOT CONSISTENT WITH THE PUBLISHED APCH) ALTHOUGH THIS IS NOT WHAT WE READ BACK. THE SIT WOULD HAVE BEEN AVOIDED HAD WE ASKED THE CTLR TO REPEAT THE CLRNC AND HAD WE READ IT BACK FULLY FOR CONFIRMATION.

Data retrieved from NASA's ASRS site as of January 2009 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.