Date: 201506
Local time of day: 1801-2400
Location: ZZZZ.Airport, FO
Flight conditions: VMC
Weather elements / visibility: 10
Light: Night
Aircraft: B767-300 and 300 ER
Mission: Cargo / Freight / Delivery
Flight phase: Initial Climb; Takeoff / Launch
Aircraft component: Air Data Computer
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Human factors: Workload; Troubleshooting; Distraction; Confusion
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Aircraft Equipment Problem Dissipated; Flight Crew Became Reoriented; Flight Crew FLC Overrode Automation; Flight Crew Overcame Equipment Problem; Flight Crew Returned To Clearance; General Maintenance Action
Contributing factors: Aircraft; Airspace Structure; Human Factors
Primary problem: Aircraft

Narrative: All ground operations were normal. On taxi out the First Officer (FO) did verbalized the ground speed and map were OK. The first indication of a problem was at my (Captain) callout of 80 Knots. There was already a 5 Knot split in the 2 primary airspeed indicators. We continued the takeoff. By rotation; the airspeed difference had grown to 10 Knots. The FO choice to delay the rotation due to the speed difference. On climb out the difference was 15 knots; and we received a Rudder Ratio and Ail Lockout EICAS message. Everything was delayed at this point; we delayed selecting V-Nav; and also delayed selecting an auto-pilot. The fight director drop off. Flap retraction was also delayed. This is a very complex departure out of [this airport]; and the airport is very noise sensitive; plus the added traffic in the FIR. The difference in airspeed indicators may have registered a flap overspeed during flap retraction. (unknown; if we did or did not?) We also do not know if we set off any noise sensors on climb out? The International Relief Officer (IRO) started with the checklist; which directed us to crosscheck the airspeed with the backup airspeed indicator; which showed my (Captains) speed was the correct airspeed. I asked the FO to select Alt. Air Data. he had called for auto-pilot on; which was placed on Center auto-pilot. I ask him to disconnect; and place back on my Left side. Again due to delay in getting auto-pilot on; and delay in selecting V-Nav; we do now know if we were outside of the departure path on the SID. After working the problem with the IRO; and climbing out; all indications went away; about 13;000 feet. We continued the climb; to get out of a very busy FIR. I the Captain; call [Maintenance]; and adviced them of our problem. Since all indication were normal at this point in time; we continued [flight]; without any further problems.


Second narrative: [Report Narrative Contained No Additional Information].


Synopsis: The flight crew experienced an airspeed variance during takeoff roll and climbout. They performed checklists which validated the correct airspeed input and continued. However; they expressed concern of a possible flap over speed and a noise abatement deviation.