MD11 crew returned to departure station when all items on the first officer's CADC system failed.

Attributes
ACN	515154
Time
Date	200106
Day	Tue
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : dfw.airport
State Reference	TX
Altitude	msl single value : 4000
Environment
Light	Night
Aircraft 1
Controlling Facilities	tracon : d10.tracon
Operator	common carrier : air carrier
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : takeoff climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	515154
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : acft instruments eicas other flight crewa other flight crewb
Resolutory Action	flight crew : landed in emergency condition flight crew : declared emergency flight crew : diverted to another airport other
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Emergency landing. At approximately 130 KTS on takeoff, airspeed comparator changed bugs to amber, indicating CADC failure. Takeoff was continued and we switched to departure control. We lost autothrottles, elevator feel, flap limiting, and all first officer's CADC functions, and autoplt. First officer's compass and attitude reference were affected. An emergency was declared. We climbed to 10000 ft to dump fuel and returned to dfw for a normal landing below maximum landing weight.

Original NASA ASRS Text

Title: MD11 CREW RETURNED TO DEP STATION WHEN ALL ITEMS ON THE FO'S CADC SYS FAILED.

Narrative: EMER LNDG. AT APPROX 130 KTS ON TKOF, AIRSPD COMPARATOR CHANGED BUGS TO AMBER, INDICATING CADC FAILURE. TKOF WAS CONTINUED AND WE SWITCHED TO DEP CTL. WE LOST AUTOTHROTTLES, ELEVATOR FEEL, FLAP LIMITING, AND ALL FO'S CADC FUNCTIONS, AND AUTOPLT. FO'S COMPASS AND ATTITUDE REF WERE AFFECTED. AN EMER WAS DECLARED. WE CLBED TO 10000 FT TO DUMP FUEL AND RETURNED TO DFW FOR A NORMAL LNDG BELOW MAX LNDG WT.

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.