A319 TCASII RA resolution causes altitude deviation on approach phl.

Attributes
ACN	445850
Time
Date	199908
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : phl.airport
State Reference	PA
Altitude	msl bound lower : 5500 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl.tracon
Operator	common carrier : air carrier
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : traffic pattern arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : phl.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	pilot : atp pilot : multi engine
Experience	flight time last 90 days : 150 flight time total : 16000
ASRS Report	445850
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne critical other anomaly other
Independent Detector	atc equipment : conflict alert aircraft equipment : tcas other controllera other flight crewa
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Miss Distance	vertical : 500
Supplementary
Problem Areas	ATC Human Performance Environmental Factor Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

Heading assigned by approach control at 6000 ft for vectors to runway 27R. We were informed about VFR traffic in front of us at 6500 ft. We immediately received a TCASII advisory. A short time after this, we received an RA to 'monitor vertical speed' and had to descend to 5500 ft. We reported this RA to approach control. After receiving 'clear of conflict' we then climbed back to 6000 ft and eventually landed on runway 27R.

Original NASA ASRS Text

Title: A319 TCASII RA RESOLUTION CAUSES ALTDEV ON APCH PHL.

Narrative: HEADING ASSIGNED BY APCH CTL AT 6000 FT FOR VECTORS TO RWY 27R. WE WERE INFORMED ABOUT VFR TFC IN FRONT OF US AT 6500 FT. WE IMMEDIATELY RECEIVED A TCASII ADVISORY. A SHORT TIME AFTER THIS, WE RECEIVED AN RA TO 'MONITOR VERT SPD' AND HAD TO DSND TO 5500 FT. WE RPTED THIS RA TO APCH CTL. AFTER RECEIVING 'CLR OF CONFLICT' WE THEN CLBED BACK TO 6000 FT AND EVENTUALLY LANDED ON RWY 27R.

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.