A B737-200 flight crew responded to a TCASII RA. Altitude deviation altitude excursion.

Attributes
ACN	317018
Time
Date	199509
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : air
State Reference	OH
Altitude	msl bound lower : 25000 msl bound upper : 25800
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Route In Use	enroute other
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	other : unknown
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 12000 flight time type : 4000
ASRS Report	317018
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 9181 flight time type : 1580
ASRS Report	316848
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Cruise at FL250 (IMC). TCASII gave a TA 'traffic.' we scaled down the TCASII screen to 10 NM and saw traffic at 10 O'clock climbing. Our TA turned to RA instructing us to 'climb.' we climbed to 25800 ft and received 'clear of conflict.' we then descended back to assigned altitude FL250. Supplemental information from acn 316848: target climbing toward us. Received RA 'climb' command in excess of 2000 FPM. I immediately disconnected autoplt and autothrottles and followed TCASII. ATC was immediately contacted. ATC informed us the only target he was working was clear to climb to FL240. Captain and I assumed target probably had a high rate of climb. Target was off our TCASII scope before we could determine his level-off altitude.

Original NASA ASRS Text

Title: A B737-200 FLC RESPONDED TO A TCASII RA. ALTDEV ALT EXCURSION.

Narrative: CRUISE AT FL250 (IMC). TCASII GAVE A TA 'TFC.' WE SCALED DOWN THE TCASII SCREEN TO 10 NM AND SAW TFC AT 10 O'CLOCK CLBING. OUR TA TURNED TO RA INSTRUCTING US TO 'CLB.' WE CLBED TO 25800 FT AND RECEIVED 'CLR OF CONFLICT.' WE THEN DSNDED BACK TO ASSIGNED ALT FL250. SUPPLEMENTAL INFO FROM ACN 316848: TARGET CLBING TOWARD US. RECEIVED RA 'CLB' COMMAND IN EXCESS OF 2000 FPM. I IMMEDIATELY DISCONNECTED AUTOPLT AND AUTOTHROTTLES AND FOLLOWED TCASII. ATC WAS IMMEDIATELY CONTACTED. ATC INFORMED US THE ONLY TARGET HE WAS WORKING WAS CLR TO CLB TO FL240. CAPT AND I ASSUMED TARGET PROBABLY HAD A HIGH RATE OF CLB. TARGET WAS OFF OUR TCASII SCOPE BEFORE WE COULD DETERMINE HIS LEVEL-OFF 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.