Method and device for implementing the thrust reversers of an aircraft

1. A method for implementing thrust reversers, upon a landing or a takeoff, of an aircraft provided with at least two turboengines, the speeds of which are individually controlled, between an idling speed and a full speed, by throttle levers respectively associated with said engines, said thrust reversers being controlled by at least one control member ( 1 ) for being able to switch from an inactive folded position to an active deployed position and, reversely, from said active deployed position to said inactive folded position,

wherein the successive steps are automatically performed:

a) a deployment (E 3 ) of said beforehand armed thrust reversers when:

an actual speed of said engines is at the most equal to a low predetermined speed threshold;

the actual speed of the aircraft is higher than a first predetermined speed threshold; and

said aircraft is considered being in contact with the ground;

b) an application (E 5 ) to said engines of a predetermined speed being at least equal to said low speed threshold as long as the speed of the aircraft is higher than said first speed threshold;

c) as soon as the speed of said aircraft is at the most equal to said first speed threshold, a reduction (E 6 ) of the speed of said engines so that they reach a speed at the most equal to said low speed threshold;

d) then, an folding (E 7 ) of said thrust reversers.

2. A method according to claim 1 , wherein said thrust reversers are folded when the speed of said aircraft is at the most equal to a second predetermined speed threshold, said second speed threshold being lower than said first predetermined speed threshold.

3. A method according to claim 1 , wherein the thrust reversers are armed if the following conditions are met:

a pilot has selected (E 1 ) a reverse thrust corresponding to said predetermined speed to be applied to the engines at step b);

the pilot has put the control member ( 1 ) of said thrust reversers in a predefined position, referred to as an automatic position;

the aircraft is in one of the two following configurations:

an approach configuration before a landing;

a takeoff configuration.

4. A method according to claim 1 , wherein, should at least one of said thrust reversers break down, a new speed to be applied at step b) is determined for each one of said engines.

5. A method according to claim 1 , wherein, in the case of a landing, the thrust reversers are armed if the following conditions are met:

a pilot has recorded the landing parameters;

the pilot has put (E 2 ) the control member ( 1 ) of said thrust reversers in a predefined position, referred to as an automatic position;

the aircraft is in an approach configuration;

and in that said speed to be applied to the engines at step b) is determined as a function of said recorded parameters and of the actual landing conditions so as to be optimal.

6. A control device ( 2 ) for implementing the method as specified in claim 1 , comprising:

a deployment logic device ( 15 ) for controlling said deployment (E 1 ) of the thrust reversers;

speed application logic devices ( 22 ) each allowing said application (E 5 ) of the predetermined speed to one of said engines to be controlled;

speed reduction logic devices ( 24 ) each allowing said reduction (E 6 ) of a speed of one of said engines to be controlled; and

folding logic devices ( 26 ) each allowing said folding (E 7 ) of the thrust reverser of one of said engines to be controlled.

7. A device according to claim 6 , further comprising a position return logic device ( 20 ) allowing said check (E 4 ) of the correct deployment of said thrust reversers to be performed.

8. A device according to claim 7 , wherein said device is connected, via a link ( 10 , 11 ), to at least one of the following means of said aircraft:

one or more flight controls ( 3 );

one or more controls of the landing gear ( 4 );

one or more flight data devices ( 5 );

a throttle lever device ( 6 );

the control member ( 1 ) of said thrust reversers;

so as to receive signals representative of information being able to be used by said logic devices for deployment ( 15 ), speed application ( 22 ), speed reduction ( 24 ), folding ( 26 ) and position return ( 20 ).

9. A device according to claim 7 , wherein said device is further connected, via a link ( 12 ), to a control interface ( 7 ) connected to an electronic control ( 8 ) of said engines and to a control unit ( 9 ) of said thrust reversers, so as to receive from said control interface ( 7 ) information signals being able to be used by said logic devices for speed application ( 22 ), speed reduction ( 24 ), folding ( 26 ) and position return ( 20 ) and to transmit to it control signals respectively from said engines and said thrust reversers.

10. An aircraft, comprising a control device ( 2 ) according to claim 6 .