Narrative:

Captain and first officer operated the first portion of the flight while international reserve officer (international relief officer) [#2] and I took our rest. Somewhere [during the flight]; we were called to the flight deck for crew swap; where international relief officer [#2] relieved first officer while I made fresh coffee. When I returned to the flight deck to relieve [the] captain; we were made aware of captain's condition and discussed the possibility that we might not want to continue to our planned destination.... At that time the captain confirmed that this would be a good decision considering all aspects of our trip ahead. After conferring with dispatch and a call to [dispatch]; the decision to make a precautionary diversion was finalized and a plan put into action. Upon further discussion; the decisions to place first officer as acting captain and place myself as flying pilot were made. Captain was alert and present for all decisions and to provide guidance as we executed the diversion. Due to our existing fuel load and forecast landing weight; we coordinated and executed a fuel jettison to comply with landing weight/[performance] limitations at [the diversion airport]. A normal approach and landing were made and the aircraft was taxied to parking. Additional guidance or training as to whether or not to declare an emergency as a result of medical deviation would be helpful to increase safety. In this case in particular; there were three fully type rated and capable crew members to complete the flight with an adequate level of safety but in the case of a more severe emergency or with a smaller crew; safety might have been compromised.

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Original NASA ASRS Text

Title: B777 International Reserve Officer reported that the First Officer was made acting Captain when the flight diverted due to the Captain's incapacitating illness. Flight was completed without incident.

Narrative: Captain and First Officer operated the first portion of the flight while International Reserve Officer (IRO) [#2] and I took our rest. Somewhere [during the flight]; we were called to the flight deck for crew swap; where IRO [#2] relieved First Officer while I made fresh coffee. When I returned to the flight deck to relieve [the] Captain; we were made aware of Captain's condition and discussed the possibility that we might not want to continue to our planned destination.... At that time the Captain confirmed that this would be a good decision considering all aspects of our trip ahead. After conferring with dispatch and a call to [dispatch]; the decision to make a precautionary diversion was finalized and a plan put into action. Upon further discussion; the decisions to place First Officer as acting Captain and place myself as flying pilot were made. Captain was alert and present for all decisions and to provide guidance as we executed the diversion. Due to our existing fuel load and forecast landing weight; we coordinated and executed a fuel jettison to comply with landing weight/[Performance] limitations at [the diversion airport]. A normal approach and landing were made and the aircraft was taxied to parking. Additional guidance or training as to whether or not to declare an emergency as a result of medical deviation would be helpful to increase safety. In this case in particular; there were three fully type rated and capable crew members to complete the flight with an adequate level of safety but in the case of a more severe emergency or with a smaller crew; safety might have been compromised.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.