Narrative:

While being vectored for mmu ILS runway 23, we received an RA commanding a descent from 3000 ft MSL. I promptly initiated a descent, but deviated from our assigned altitude by only 200 ft when TCASII reported 'clear of conflict.' I returned to our assigned altitude and my first officer attempted to notify ATC. New york approach was so busy, that she was unsuccessful. ATC instructed us to descend to 2000 ft MSL. A few moments later, we received a traffic alert, with a target at 11 O'clock position, and 300 ft below and climbing. The target appeared to be converging. Moments later, we received an RA commanding a climb. I initiated a climb to 2300 ft when we cleared the conflict. ATC then pointed out the traffic. We reported the RA and our 300 ft altitude deviation, and ATC instructed us to contact morristown tower. We landed at mmu uneventfully a few mins later. The mmu ATIS reported that the ILS runway 23 final approach course transited the caldwell class D airspace. The proximity of these ny/nj airports, the volume of air traffic, the mix of airline/cpr jet/reciprocating traffic and overlying ny class B airspace funnels traffic into a very confined space, thereby compromising safety. This particular aircraft is equipped with TCASII. The other 2 citation jet aircraft that I operate are not similarly equipped. I wonder how often I pass in close proximity to other aircraft under similar circumstances and never know it.

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Original NASA ASRS Text

Title: C560 CREW HAD 2 TCASII RA'S WHILE BEING VECTORED TO THE ILS AT MMU.

Narrative: WHILE BEING VECTORED FOR MMU ILS RWY 23, WE RECEIVED AN RA COMMANDING A DSCNT FROM 3000 FT MSL. I PROMPTLY INITIATED A DSCNT, BUT DEVIATED FROM OUR ASSIGNED ALT BY ONLY 200 FT WHEN TCASII RPTED 'CLR OF CONFLICT.' I RETURNED TO OUR ASSIGNED ALT AND MY FO ATTEMPTED TO NOTIFY ATC. NEW YORK APCH WAS SO BUSY, THAT SHE WAS UNSUCCESSFUL. ATC INSTRUCTED US TO DSND TO 2000 FT MSL. A FEW MOMENTS LATER, WE RECEIVED A TFC ALERT, WITH A TARGET AT 11 O'CLOCK POS, AND 300 FT BELOW AND CLBING. THE TARGET APPEARED TO BE CONVERGING. MOMENTS LATER, WE RECEIVED AN RA COMMANDING A CLB. I INITIATED A CLB TO 2300 FT WHEN WE CLRED THE CONFLICT. ATC THEN POINTED OUT THE TFC. WE RPTED THE RA AND OUR 300 FT ALTDEV, AND ATC INSTRUCTED US TO CONTACT MORRISTOWN TWR. WE LANDED AT MMU UNEVENTFULLY A FEW MINS LATER. THE MMU ATIS RPTED THAT THE ILS RWY 23 FINAL APCH COURSE TRANSITED THE CALDWELL CLASS D AIRSPACE. THE PROX OF THESE NY/NJ ARPTS, THE VOLUME OF AIR TFC, THE MIX OF AIRLINE/CPR JET/RECIPROCATING TFC AND OVERLYING NY CLASS B AIRSPACE FUNNELS TFC INTO A VERY CONFINED SPACE, THEREBY COMPROMISING SAFETY. THIS PARTICULAR ACFT IS EQUIPPED WITH TCASII. THE OTHER 2 CITATION JET ACFT THAT I OPERATE ARE NOT SIMILARLY EQUIPPED. I WONDER HOW OFTEN I PASS IN CLOSE PROX TO OTHER ACFT UNDER SIMILAR CIRCUMSTANCES AND NEVER KNOW IT.

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.