Restarting a plurality of engines of an aircraft

1. A method of restarting a plurality of engines that have stopped in flight among a set of N engines of an aircraft, N≥2, the method being implemented by a system for automated management of restarting engines in flight that includes a plurality of controllers, each engine among said set of N engines of the aircraft being managed by a corresponding controller of said plurality of controllers, in which each controller of said plurality of controllers which is controlling one engine i of said set of N engines, i=1, . . . , N, and which detects that said one engine i has stopped, executes the following steps:

cutting off a supply of energy to said one engine i;

effecting windmilling of said one engine i; and

identifying at least one other engine of said set of N engines that has stopped;

wherein at least one of said plurality of controllers effects an engine restarting prioritization of all of the plurality of engines that have stopped of said set of N engines, including the following steps:

collecting information concerning a state of health of each engine of said set of N engines from the plurality of controllers controlling said set of N engines;

determining a probability of restarting each engine of all of the plurality of engines that have stopped of said set of N engines from the information collected concerning the state of health of each engine of said set of N engines,

wherein restarting each engine of all of the plurality of engines that have stopped of said set of N engines uses a source of energy equipped on the aircraft;

determining a sequential order of restarting all of the plurality of engines that have stopped of said set of N engines as a function of the information representing the probability of restarting each engine of all of the plurality of engines that have stopped of said set of N engines; and

maintaining windmilling of the one engine i by the corresponding controller of said plurality of controllers, until said one engine i is selected from the sequential order of restarting all of the plurality of engines that have stopped of said set of N engines for restarting using the source of energy equipped on the aircraft.

2. The method according to claim 1 , in which the information collected from the plurality of controllers includes:

an indication of a mode of operation of each engine of said set of N engines;

an indication of vibrations sensed by sensors of each engine of said set of N engines;

an indication of a temperature sensed by sensors of each engine of said set of N engines;

an indication of a status of a starting system of each engine of said set of N engines; and

an indication of an energy supply status of each engine of said set of N engines.

3. The method according to claim 2 , wherein the probability of restarting each engine of all of the plurality of engines that have stopped of said set of N engines is a health status score of each engine of all of the plurality of engines that have stopped of said set of N engines and in which the health status score depends on:

a temperature margin of each engine of all of the plurality of engines that have stopped of said set of N engines relative to one or more first predefined thresholds;

a peak vibration value sensed at a level of each engine of all of the plurality of engines that have stopped of said set of N engines during the flight relative to one or more second predefined thresholds;

an operational status of the starting system of each engine of all of the plurality of engines that have stopped of said set of N engines; and

an operational status of the energy supply of each engine of all of the plurality of engines that have stopped of said set of N engines.

4. A system for automated management of restarting, in flight, engines of an aircraft, the aircraft including a set of N engines, N>2, said system including a plurality of controllers, each corresponding engine of the set of N engines of the aircraft being managed by a corresponding controller of said plurality of controllers,

wherein each corresponding controller of said plurality of controllers controlling the corresponding engine i of said set of N engines, i=1, . . . , N detects whether said corresponding engine i has stopped, and includes electronic circuitry configured to implement the following steps:

cutting off a supply of energy to said corresponding engine i;

effecting windmilling of said corresponding engine i;

verifying whether at least one other engine j, j=1, . . . , N, j≠i, of said set of N engines that has stopped; and

if the at least one other engine has not stopped, effecting an attempt to restart said corresponding engine i, using a source of energy equipped on the aircraft; and

wherein at least one of said plurality of controllers includes electronic circuitry configured to implement an engine restarting prioritization if the at least one other engine j of said set of N engines has stopped, including the following steps:

collecting, from the plurality of controllers, information concerning a state of health of each engine of the set of N engines;

determining a probability of successfully restarting each engine of all engines of the set of N engines that have stopped using the source of energy equipped on the aircraft, wherein the probability is calculated from the information concerning the state of health of each engine of the set of N engines; and

determining a sequential order of restarting all engines of the set of N engines that have stopped as a function of the probability of successfully restarting each engine of all engines of the set of N engines that have stopped, wherein restarting all engines of the set of N engines that have stopped uses the source of energy equipped on the aircraft; and

maintaining windmilling of the corresponding engine i by the corresponding controller, of said plurality of controllers, until said corresponding engine i is selected for restarting, from the sequential order of restarting each engine of all engines of the set of N engines that have stopped, using the source of energy equipped on the aircraft.

5. The system for automated management of restarting, in flight, engines, according to claim 4 , incorporated onto an aircraft including a set of N engines, N>2.