Air carrier had TCASII RA and responds.

Attributes
ACN	196280
Time
Date	199112
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : ldn
State Reference	VA
Altitude	msl bound lower : 29000 msl bound upper : 29700
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 150 flight time total : 11000 flight time type : 6000
ASRS Report	196280
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

Cruise at FL290 near linsen VOR, working ZDC 132.27. TCASII gave TA immediately followed by RA and commanding a 1500 FPM climb. Traffic was shown on TCASII climbing at our 2 O'clock position. I did not have visual contact because we were in the clouds. I climbed to 29700 while asking the first officer to notify ATC of our climb because of our RA. She stated the traffic was level and no conflict. After the traffic went under our aircraft, the ivsi cleared. TCASII stated monitor vertical speed and I returned to FL290. I really don't think that a conflict occurred but I had no choice but to climb because we were IFR. I do feel that aircraft climbing and descending could prevent TCASII alerts if they used a climb rate of 500 FPM on the last thousand ft per the instrument flying handbook.

Original NASA ASRS Text

Title: ACR HAD TCASII RA AND RESPONDS.

Narrative: CRUISE AT FL290 NEAR LINSEN VOR, WORKING ZDC 132.27. TCASII GAVE TA IMMEDIATELY FOLLOWED BY RA AND COMMANDING A 1500 FPM CLB. TFC WAS SHOWN ON TCASII CLBING AT OUR 2 O'CLOCK POS. I DID NOT HAVE VISUAL CONTACT BECAUSE WE WERE IN THE CLOUDS. I CLBED TO 29700 WHILE ASKING THE FO TO NOTIFY ATC OF OUR CLB BECAUSE OF OUR RA. SHE STATED THE TFC WAS LEVEL AND NO CONFLICT. AFTER THE TFC WENT UNDER OUR ACFT, THE IVSI CLRED. TCASII STATED MONITOR VERT SPD AND I RETURNED TO FL290. I REALLY DON'T THINK THAT A CONFLICT OCCURRED BUT I HAD NO CHOICE BUT TO CLB BECAUSE WE WERE IFR. I DO FEEL THAT ACFT CLBING AND DSNDING COULD PREVENT TCASII ALERTS IF THEY USED A CLB RATE OF 500 FPM ON THE LAST THOUSAND FT PER THE INST FLYING HANDBOOK.

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.