B777 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Critical
Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution
Aircraft
During takeoff roll; the Master Caution Light and Bleed Leak Right EICAS message illuminated. Once airborne; other EICAS messages were received and it was determined that the complete right side of the pneumatic system was inoperable. Dispatch and [maintenance] were consulted about the continuation of the flight to the destination. Subsequently; we were advised by ATC that an [aircraft] on the ground reported seeing large pieces of debris falling from behind our aircraft. We were also advised by the Flight Attendants that a loud noise was heard during takeoff. It could not be determined if it was from our aircraft or FOD on the runway. The decision was made to return to [departure airport]. Approach and landing were normal.
The reporter stated that the flight crew was unaware of what happened; other than the loss of duct pressure for the right hand side. The reporter stated that viewing the damaged area from the ground; it looked like the pneumatic system blew apart internally. The reporter also stated that they were able to see damage inside the air conditioning compartment; including blowing out a section of the fuselage. The reporter stated that the damage to the fuselage did not affect the pressurization of the aircraft. The reporter stated that the air cycle was located forward of the damaged area and could not determine if it was damaged or if it caused the damage.
B777 Captain reported returning to departure airport after the complete right side pneumatic system was determined to be inoperative.