Captain climbed in response to TCASII RA even though first officer had the traffic in sight.

Attributes
ACN	262205
Time
Date	199401
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : rbv
State Reference	NJ
Altitude	msl bound lower : 3000 msl bound upper : 3500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 150 flight time total : 7000 flight time type : 2100
ASRS Report	262205
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe
Independent Detector	atc equipment other atc equipment : unspecified aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 4000 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Traffic observed on TCASII, no visual. We were notified by ATC about it. First officer (PNF) reported traffic in sight. However, it was not seen by captain (PF). At the same time, it turned towards us, and our TCASII issued an RA. Since I did not see the traffic, I initiated a climb as directed by TCASII. Once 'clear of conflict,' we returned to our assigned altitude.

Original NASA ASRS Text

Title: CAPT CLBED IN RESPONSE TO TCASII RA EVEN THOUGH FO HAD THE TFC IN SIGHT.

Narrative: TFC OBSERVED ON TCASII, NO VISUAL. WE WERE NOTIFIED BY ATC ABOUT IT. FO (PNF) RPTED TFC IN SIGHT. HOWEVER, IT WAS NOT SEEN BY CAPT (PF). AT THE SAME TIME, IT TURNED TOWARDS US, AND OUR TCASII ISSUED AN RA. SINCE I DID NOT SEE THE TFC, I INITIATED A CLB AS DIRECTED BY TCASII. ONCE 'CLR OF CONFLICT,' WE RETURNED TO OUR ASSIGNED ALT.

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.