A method for controlling an aircraft having at least two engines burning fuel and a transmission system connected to a rotary wing, each engine having a power shaft connected to the transmission system. An energy-saving phase comprises at least one energy-saving period comprising controlling, at an active rating, with a control system, one active engine from the at least two engines, and using the control system to stop or control, at an inactive rating, each inactive engine from the at least two engines that is not the active engine.