Method for synchronising the engines of an airplane with dual intermediate state

A method for synchronising there between engines of an airplane by an electronic chip encoding at least one activation logic per engine, the activation logic being intended to check the safety and/or activation conditions in order to apply the synchronisation, with each activation logic defining synchronization states of the engines, including at least a deactivated state, an armed state, and an activated state, with the method comprising, per engine:

• receiving, with the electronic chip, an activation order;
• when the activation order is issued by a pilot of the airplane and received with the electronic chip, switching the activation logic encoded on the electronic chip from the deactivated state to the armed state;
• periodically checking, with the activation logic encoded on the electronic chip, at least one of the safety and activation conditions relative to said states, in order to define whether said conditions are met or not met,
• switching the activation logic encoded on the electronic chip from the armed state to the activated state when some of the safety and/or activation conditions are met;
• receiving, with the electronic chip, a deactivation order;
• and
• when the deactivation order is issued by the pilot and received with the electronic chip or when some of said safety conditions are not met, switching the activation logic encoded on the electronic chip from the activated state or the armed state to the deactivated state,
• wherein:
• switching the activation logic encoded on the electronic chip from the armed state to the activated state is carried out via a first and then a second successive intermediate state of the activation logic encoded on the electronic chip,
• every instance of switching the activation logic encoded on the electronic chip from the second intermediate state to the activated state involves exchanging such data between the engines carried out by an exchange digital link, so that:
• switching the activation logic encoded on the electronic chip of one of the engines to the activated state requires that the safety and activation conditions applied to the other engine(s) are all met,
• and if the activation logic encoded on the electronic chip of one of the engines switches to the deactivated state, the activation logic encoded on the electronic chip of the other engine(s) automatically does so as well;
• and
• for each engine, switching the activation logic encoded on the electronic chip from the armed state to the first and then to the second intermediate state takes place automatically when a first portion and then a second portion, different from the first one, of at least one of the safety and activation conditions are met.