B747 Undifferentiated or Other Model
Flight Crew Last 90 Days 100; Flight Crew Total 28000; Flight Crew Type 900
Other / Unknown
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; Flight Crew Overcame Equipment Problem; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
Approximately 1:30 hours into our flight the first officer lost all of his flight instruments. We discovered we lost the right Air Data Computer. The first officer selected left on his Air Data switch located on the instrument source select panel to recover his airspeed; altimeter and VSI to his PFD (Primary Flight Display).We called dispatch to get a 3 way call with maintenance. Maintenance told us it's Captains emergency authority to pull and reset the Air Data circuit breaker. Since there was NO GUIDANCE in the QRH to deal with a lost Air Data Computer I pulled and reset the circuit breaker to no avail.I made the decision to return to ZZZ based on the fact I pulled the Air Data circuit breaker; and did not want fly and additional 12 hours on one Air Data computer.We coordinated our return with dispatch and ATC. We started dumping fuel 80 miles out at 31;000 feet. We then flew a normal arrival and approach.
[Report narrative contained no additional information.]
The Right Air Data Computer on a B747 failed and the Crew elected to return to the departure airport.