It would be crewed to the highest CE load so you the return could be empty but if the outbound had 45 or more in CE there would be 6 crew rostered
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If a morning rotation had a load justifying 6 crew outbound but only 4 inbound, and an evening rotation was loaded the other way, would both have 6 crew both ways, or would two from the first outward trip have an idle day at the destination in order to make up the number on the later return?