On ULR flight at Turkish Airlines.
Composition of the crew is
Case 1 Two captains and one first officer
Case 2 One captain and two first officer one being P3.
First case: Captain 1 flies with FO the first leg while captain 2 doesn't do anything except relieving captain 1 when he is on rest and sits on right when FO is on rest. Return is other way around Captain 2 flies the return leg.
Case 2. Captain flies the first or return leg. P3 relieves the captain. p4 or p5 on the right seat.
Fully augmented crew 4 pilots.. 2 captains and 2 first officers.
First crew flies the first leg, while other crew rests in the back. Return flight other way around.