Date: 201703
Local time of day: 1201-1800
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Light: Daylight
Aircraft: B767 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Air Data Computer
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Confusion; Workload; Distraction
Anomaly: Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Fuel Issue
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We initiated a reduced power takeoff from runway 8R; the first officer was flying. At 100 knots; I cross-checked airspeed indicators and noticed a slight disparity between indicators (perhaps 3 knots). As we were in the high-speed regime; I monitored airspeed and called V1-rotate. I did not notice a significant discrepancy between indicators as we lifted off.Shortly after take-off; we switched to departure control. I checked in and reported altitude leaving; which elicited a request to 'confirm altitude' from the controller. At about that time; I noticed we had a disparity of 10-15 knots between the airspeed indicators. We also noticed that the First Officer's altimeter was behaving erratically. After cross checking the standby instruments; it was clear that his indicators were in error. I took the controls of the plane; and asked to level off at 8000 FT. By now we had several EICAS messages including airspeed disagree; alt disagree; aileron lockout; and rudder ratio. The conditions were daytime; VFR.I called for the AIRSPEED DISAGREE checklist; and we stabilized the plane level at 8000 FT. While the relief pilot was locating the checklist; the first officer and I agreed that his air data source was giving him bad information. We switched his air data source and immediately the airspeed and altitude anomalies went away.We discussed the safety of continuing with multiple failures; and after conferring with dispatch; agreed that a return to [departure airport] was the safest course of action. I briefed the lead flight attendant; and made an announcement to the people that we were going to return to the departure airport. We coordinated the dumping of fuel with approach; followed the fuel dump checklist; and dumped all of the center tank fuel. As we were still overweight; I wanted to know whether Maintenance and Dispatch preferred an overweight landing or if we should burn the remaining fuel to max landing weight.At some point the antiskid EICAS message annunciated.  After running the checklist; it was clear that the autobrakes were not available and we had to calculate landing data for a non-normal configuration. Dispatch indicated that Maintenance would prefer a landing that was not overweight. Now that we had the antiskid message; we concurred and configured early to burn additional fuel. I made a Satcom call to dispatch requesting a patch to Maintenance; as I wanted to know whether there was anything that we might have overlooked. The controller was somewhat exasperated and explained that the failures were unrelated and that he could only recommend that we refer to the flight manual. We continued flying to burn fuel. I briefed the flight attendants; and again made an announcement to keep the people informed.We made several requests from dispatch for landing performance data for runway 8R. I also asked whether runway 8R had an engine out go-around procedure; which seemed to confuse the dispatcher. He asked for us to confirm that both engines were operating; which we did. He explained that he was having difficulty obtaining the landing performance data for 8R; and suggested that Sabre was giving him trouble. He indicated that he had requested a technician to assist him with Sabre; to obtain the data. We calculated our landing performance with the FM; and asked for his concurrence.We accomplished a normal approach and landing; touchdown was smooth and brakes were gradually applied below 80 knots. After clearing the runway; the plane was chocked by the Fire Department; and they measured brake temperatures. Once they confirmed everything was normal (which our brake temps indicated); we taxied to the gate.




Synopsis: B767 Captain reported airspeed; altitude differences from the First Officer along with AILERON LOCKOUT and RUDDER RATIO alerts. An air data computer malfunction was suspected; so fuel was dumped and the flight returned to the departure airport.