| 主权项 |
1. A method of managing a power plant for a rotary wing aircraft, said power plant comprising at least two main engines, at least one secondary engine, and a main power transmission gearbox (MGB), said main and secondary engines driving said MGB mechanically in order to rotate at least one main outlet shaft of said MGB, said main outlet shaft being constrained to rotate with a main rotor of said aircraft, each main engine being capable of delivering continuously a first main mechanical power that is less than or equal to a maximum continuous main mechanical power MCPM and of delivering temporarily an emergency second main mechanical power that is greater than or equal to a guaranteed minimum emergency main mechanical power OEIPMIN, each secondary engine being capable of delivering continuously a secondary mechanical power that is less than or equal to a maximum continuous secondary mechanical power MCPS, the method being characterized by the following steps:
performing an engine health check on each main engine determining a level of degradation of each main engine and a main mechanical power margin CSMP11, CSMP12 for each main engine; determining a coefficient K as being greater than or equal to zero where:
K =|min[0,CSMP11,CSMP12]|CSMP11 and CSMP12 being said main mechanical power margins of each of said main engines respectively, “0” being the value zero, “min” being a function returning the minimum value from among a series of values, and “|”| being the absolute value function;
controlling each main engine to deliver a main mechanical power; and controlling each secondary engine to deliver two distinct mechanical power levels, said secondary mechanical power level delivered by each secondary engine enabling each main engine and each secondary engine to act together to deliver mechanical power that is greater than or equal to sufficient mechanical power SMP for enabling said aircraft to fly using said main rotor, said two secondary mechanical power levels being a first secondary mechanical power MPS1 and a second secondary mechanical power MPS2, said second secondary mechanical power MPS2 being greater than said first secondary mechanical power MPS1 such that:
MPS2=MPS1+K.Pdet where Pdet is a predetermined main mechanical power value and “.” is the multiplication function, said second secondary mechanical power MPS2 thus serving to compensate for a loss of main mechanical power in at least one main engine. |
