B767 flight crew reported they got a Right Bleed Duct Leak EICAS message in cruise. They contacted Dispatch and maintenance and they decided to return to the departure airport.

Narrative

I was the flying First Officer on Flight XXXX that departed ZZZ1 on Day 0. The flight was proceeding normally until around XA:30 zulu when Captain was first to notice a blue status message had appeared on the center screen. After pushing the status button; I remember a white status message displayed on the lower MFD but I looked away to open content and the FM on my iPad. By the time I looked back; the message had extinguished. We discussed if either of us remembered exactly what the message said and I couldn't. Approximately 5-10 minutes later; we got an amber R BLD DUCT LEAK" EICAS message and I pulled up the appropriate "(767) R BLD DUCKT LEAK" checklist and after confirming the matching conditions; we evaluated the checklist's implications (aka turning off a pack and possible pressurization effects) and then ran the checklist to completion. All this was happening past ZZZZZ intersection and coasting out with ZZZ ARTCC. At this time; the Captain called dispatch and maintenance control via SATCOM and I called the purser to ensure First Officer was awake and preparing to do our regularly scheduled crew rest swap. I monitored the SATCOM conversation as the Captain was discussing options with Dispatch and Maintenance Control and let in FO when he requested access. I caught him up on what was going on and after a quick crew discussion; a return to the US was agreed upon by the 3 of us. With the captain's concurrence; and while the Captain and FO were still conversing with Ops & Maintenance; I started coordinating with ZZZ ARTCC and ZZZZ1 (since we still had VHF coverage; even though we were out of their airspace) to get a turn back towards the Country X. When asked; we did NOT [request priority handling]. Clearance came via CPDLC to proceed directly back to ZZZZZ & ZZZZZZ and after confirming the FMS LOAD with the Captain we executed the FMS and started the turn back towards ZZZZZ. Continuing to conference with dispatch & Maintenance control; ZZZ2; ZZZ3; and ZZZ1 were all considered. ZZZ2 was ruled out due to our new limitation of avoiding flying into icing areas and the possible icing weather areas that was between us and ZZZ2; as well as a reduced maintenance capability (a consideration raised by the Maintenance controller) in ZZZ2. Given the updated estimated arrival time around XE:00 zulu; we decided that airport familiarity would be beneficial and made the decision to return to ZZZ1. After the SATCOM call ended; we held a quick conversation among the 3 of us and then the Captain called the Flight Attendants and updated them on what was going on. After that; the Captain made a PA announcement to update the passengers. We then talked amongst the 3 of us if anyone needed a rest while we were still 3.5 hours from landing at ZZZ1. No one indicated they needed a rest so we set up for a restroom break since that's what we were prepping for; during to the crew swap; when the caution light came on. A message was sent to ZZZ1 Ops notifying them that we'd need a gate and agents to assist the passengers and they responded that Gate X was open and would be our gate. The return leg was uneventful and we stayed at FL360 for as long as possible to be over storms & clouds along the STAR into to ZZZ1 and descended through a clear area to get below the cloud layer. The approach and landing were uneventful. Upon taxi in; Gate X was occupied but Gate Y was open and had ramp agents. We confirmed the change to Gate Y with Ops before pulling in and shutdown. We left the right Air System in its post-FM procedure configuration (R PACK OFF & R ISOLATION CLOSED) and started packing up to leave. The gate agent came on board and asked if we needed anything and we said that we were good. Their conversation continued with the Captain & FO in the forward galley as I packed up my things. Maintenance was arriving around this time and they started talking with the Captain and FO in the galley. As I was stepping out of the cockpit; maintenance asked us to write up an Electronic Logbook (ELB) entry for the caution light so I wrote it up and asked the Captain to confirm the message before sending it. All 3 flight crew then grabbed our bags and left."