A DC9 crew descending into hpn responded to a 'climb' RA from TCASII.

Attributes
ACN	520117
Time
Date	200107
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : dpk.vor
Altitude	msl bound lower : 2000 msl bound upper : 3000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90.tracon artcc : zbw.artcc
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : n90.tracon
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	controller : non radar pilot : cfi pilot : flight engineer pilot : multi engine pilot : atp
Experience	controller non radar : 2 flight time last 90 days : 150 flight time total : 7000 flight time type : 3000
ASRS Report	520117
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : nmac inflight encounter : weather non adherence : published procedure non adherence : far other anomaly other
Independent Detector	aircraft equipment : tcas other controllera other flight crewa
Resolutory Action	controller : issued advisory flight crew : took precautionary avoidance action flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Problem Areas	Weather ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

RA going into hpn at 2000 ft MSL. ATC gave TA approximately 30 seconds prior to our 'climb' RA. When traffic indicated -300 ft at 1 O'clock position and climbing to within -200 ft, we received TA, shortly followed by RA. I climbed aircraft immediately to 3000 ft MSL. We were very MVFR at 2000 ft and IFR at 3000 ft. I believe the arrival into white plains should keep aircraft higher for a longer period of time. We have no idea who the other aircraft was. We reported the RA to ATC while responding to the climb command. ATC gave no further information on the encounter other than to descend to 2000 ft again when possible. I believe this involved a VFR aircraft scud running in very congested airspace. The aircraft was definitely not 500 ft below clouds and endangered the lives of approximately 30 persons onboard my aircraft as well as their own. Continued education to GA pilots on the danger in scud running needs to be emphasized. ATC also seemed to be overloaded on this occasion going into hpn. I am grateful to his initial TA, and the benefits of TCASII!

Original NASA ASRS Text

Title: A DC9 CREW DSNDING INTO HPN RESPONDED TO A 'CLB' RA FROM TCASII.

Narrative: RA GOING INTO HPN AT 2000 FT MSL. ATC GAVE TA APPROX 30 SECONDS PRIOR TO OUR 'CLB' RA. WHEN TFC INDICATED -300 FT AT 1 O'CLOCK POS AND CLBING TO WITHIN -200 FT, WE RECEIVED TA, SHORTLY FOLLOWED BY RA. I CLBED ACFT IMMEDIATELY TO 3000 FT MSL. WE WERE VERY MVFR AT 2000 FT AND IFR AT 3000 FT. I BELIEVE THE ARR INTO WHITE PLAINS SHOULD KEEP ACFT HIGHER FOR A LONGER PERIOD OF TIME. WE HAVE NO IDEA WHO THE OTHER ACFT WAS. WE RPTED THE RA TO ATC WHILE RESPONDING TO THE CLB COMMAND. ATC GAVE NO FURTHER INFO ON THE ENCOUNTER OTHER THAN TO DSND TO 2000 FT AGAIN WHEN POSSIBLE. I BELIEVE THIS INVOLVED A VFR ACFT SCUD RUNNING IN VERY CONGESTED AIRSPACE. THE ACFT WAS DEFINITELY NOT 500 FT BELOW CLOUDS AND ENDANGERED THE LIVES OF APPROX 30 PERSONS ONBOARD MY ACFT AS WELL AS THEIR OWN. CONTINUED EDUCATION TO GA PLTS ON THE DANGER IN SCUD RUNNING NEEDS TO BE EMPHASIZED. ATC ALSO SEEMED TO BE OVERLOADED ON THIS OCCASION GOING INTO HPN. I AM GRATEFUL TO HIS INITIAL TA, AND THE BENEFITS OF TCASII!

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.