Altitude deviation altitude excursion after receiving TCASII RA.

Attributes
ACN	249421
Time
Date	199308
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : phl
State Reference	PA
Altitude	msl bound lower : 9300 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl tracon : bdl
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 16500 flight time type : 210
ASRS Report	249421
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : far other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 1000 vertical : 100
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Received TCASII alert, RA, to descend after ATC notified us of 2 O'clock position traffic, 10200 ft. Closing target descended and closed on our aircraft. We descended to 9300 ft while notifying ATC. They cleared us back to 10000 ft after clear of conflict. Continued to phl uneventfully.

Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION AFTER RECEIVING TCASII RA.

Narrative: RECEIVED TCASII ALERT, RA, TO DSND AFTER ATC NOTIFIED US OF 2 O'CLOCK POS TFC, 10200 FT. CLOSING TARGET DSNDED AND CLOSED ON OUR ACFT. WE DSNDED TO 9300 FT WHILE NOTIFYING ATC. THEY CLRED US BACK TO 10000 FT AFTER CLR OF CONFLICT. CONTINUED TO PHL UNEVENTFULLY.

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.