Medium large transport climbs above assigned altitude when a TCASII RA is received.

Attributes
ACN	239887
Time
Date	199304
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 7000 msl bound upper : 7400
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other other
Route In Use	enroute : on vectors
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 : 7900 flight time type : 3200
ASRS Report	239887
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

TCASII climb RA was received on downwind for runway 4R (7000 ft) at ord. A climb of 1500 FPM was initiated to 7400 ft before RA ended. ATC was notified and descent back to 7000 ft was begun. We were on 10 mi scale and the intruder was offscale. The intruder was not spotted visually and ATC didn't seem to know why we got an RA. Perhaps a larger scale on TCASII would have helped us spot the other aircraft.

Original NASA ASRS Text

Title: MLG CLBS ABOVE ASSIGNED ALT WHEN A TCASII RA IS RECEIVED.

Narrative: TCASII CLB RA WAS RECEIVED ON DOWNWIND FOR RWY 4R (7000 FT) AT ORD. A CLB OF 1500 FPM WAS INITIATED TO 7400 FT BEFORE RA ENDED. ATC WAS NOTIFIED AND DSCNT BACK TO 7000 FT WAS BEGUN. WE WERE ON 10 MI SCALE AND THE INTRUDER WAS OFFSCALE. THE INTRUDER WAS NOT SPOTTED VISUALLY AND ATC DIDN'T SEEM TO KNOW WHY WE GOT AN RA. PERHAPS A LARGER SCALE ON TCASII WOULD HAVE HELPED US SPOT THE OTHER ACFT.

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.