A method for operating an aircraft having two or more engines (102, 104), the method comprising: operating the aircraft in an asymmetric operating regime in which a first one of the two or more engines (102, 104) is operating in an active mode to provide motive power to the aircraft while a second one of the two or more engines (102, 104) is operating in a standby mode in which the second engine is de-clutched from a gearbox of the aircraft; receiving one of: an emergency exit request, and a normal exit request; in response to the emergency exit request, increasing a rotational speed of the second engine, at a maximum permissible speed rate of change associated with the second engine, to a re-clutching speed to re-clutch the second engine to the gearbox while increasing a power output of the first engine at a first maximum permissible power rate of change associated with the first engine, and when the rotational speed of the second engine reaches the re-clutching speed, increasing a power output of the second engine at a second maximum permissible power rate of change associated with the second engine; and in response to the normal exit request, increasing the rotational speed of the second engine to the re-clutching speed at a speed rate of change lower than the maximum permissible speed rate of change associated with the second engine, and when the rotational speed of the second engine reaches the re-clutching speed, increasing the power output of the second engine at a first power rate of change, the first power rate of change being lower than the second maximum permissible power rate of change associated with the second engine. operating the aircraft in an asymmetric operating regime in which a first one of the two or more engines (102, 104) is operating in an active mode to provide motive power to the aircraft while a second one of the two or more engines (102, 104) is operating in a standby mode in which the second engine is de-clutched from a gearbox of the aircraft; receiving one of: an emergency exit request, and a normal exit request; an emergency exit request, and a normal exit request; in response to the emergency exit request, increasing a rotational speed of the second engine, at a maximum permissible speed rate of change associated with the second engine, to a re-clutching speed to re-clutch the second engine to the gearbox while increasing a power output of the first engine at a first maximum permissible power rate of change associated with the first engine, and when the rotational speed of the second engine reaches the re-clutching speed, increasing a power output of the second engine at a second maximum permissible power rate of change associated with the second engine; and increasing a rotational speed of the second engine, at a maximum permissible speed rate of change associated with the second engine, to a re-clutching speed to re-clutch the second engine to the gearbox while increasing a power output of the first engine at a first maximum permissible power rate of change associated with the first engine, and when the rotational speed of the second engine reaches the re-clutching speed, increasing a power output of the second engine at a second maximum permissible power rate of change associated with the second engine; and in response to the normal exit request, increasing the rotational speed of the second engine to the re-clutching speed at a speed rate of change lower than the maximum permissible speed rate of change associated with the second engine, and when the rotational speed of the second engine reaches the re-clutching speed, increasing the power output of the second engine at a first power rate of change, the first power rate of change being lower than the second maximum permissible power rate of change associated with the second engine. increasing the rotational speed of the second engine to the re-clutching speed at a speed rate of change lower than the maximum permissible speed rate of change associated with the second engine, and when the rotational speed of the second engine reaches the re-clutching speed, increasing the power output of the second engine at a first power rate of change, the first power rate of change being lower than the second maximum permissible power rate of change associated with the second engine.