The present invention relates to a system for allowing conventional, unprepared fixed-wing aircraft to land safely on very small, unprepared areas, enabling an aerodynamic capacitance in which the airplanes can fly in a controlled manner against coherent air current, being assisted by a combined system including both the air current control mechanisms and the automatic flight control system of the aircraft.
1. A system to assist conventional fixed-wing aircraft (20) landing without a runway, said system comprising: a) a not-on-board installation (13) which in turn comprises: • air potential generating means (4,5) responsible for providing air in adjustable pressure and flow rate conditions to laminar airflow generating means; • laminar airflow generating means responsible for generating a laminar air current from the air supplied by the air potential generating means; characterized in that the not-on-board installation (13) additionally comprises: • airflow control means (2) responsible for controlling the air potential generating means and laminar airflow generating means to obtain a controlled laminar air current; • communication means for communicating with the aircraft (20) responsible for: - communicating information about the conditions of the generated laminar air current to the flight control system of the aircraft (20); - receiving information about the flight conditions on the approach of the aircraft (20) from the flight control system of the aircraft (20) and communicating them to the airflow control means (2); • trajectory generating means (3) responsible for calculating and providing the aircraft (20) with a trajectory to be followed by the aircraft (20) through the communication means to guide it to a collection area; • aircraft collecting and immobilizing means (10,11) responsible for immobilizing the aircraft (20) in the collection area once the aircraft has reached said collection area; in that the airflow control means (2) in cooperation with the flight control system of the aircraft and with interaction logic are configured for obtaining the controlled laminar air current with the suitable conditions to maintain the airworthiness of the aircraft (20) in real time, depending on its approach conditions, the conditions of the generated current itself and the trajectory calculation by the control hardware housing the interaction logic; and in that the system additionally comprises: b) an installation on board the aircraft (20) which in turn comprises: - a flight control system responsible for: • receiving information about the conditions of the generated laminar air current and the trajectory to be followed by the aircraft (20) from the not-on-board installation (13) to reach the collection area; • receiving the control strategy defining the control of the aircraft from the control hardware housing the interaction logic; • controlling the aircraft (20) depending on at least said received information; • sending information about the flight conditions on the approach of the aircraft (20) to the not-on-board installation (13); • sending information about the flight conditions on the approach of the aircraft (20) to the computing means housing the interaction logic; c) interaction logic housed in control hardware, implemented in the form of control laws of control software, responsible for: - coordinating the flight control sub-system and airflow control sub-system so that they work together to control the aircraft; - listing the coordinated operation of the flight control system of the aircraft, the control system of the aircraft collection and immobilizing means and the airflow control means; - acting by providing the instructions which must be fulfilled by each of the control systems such that the controlled and safe operation of the aircraft inside the air produced by the laminar air flow rate generating system is achieved. 2. The system according to claim 1, characterized in that the laminar airflow generating means comprise: - a pooling chamber (6) responsible for containing a specific volume of air in the thermodynamic conditions provided by the air potential generating means; - at least one purge valve (7) responsible for relieving the pressure of the pooling chamber (6) when it is activated to obtain the suitable thermodynamic conditions; - at least one nozzle responsible for exchanging the thermodynamic conditions of the air contained in the pooling chamber (6) with those necessary to form a laminar air current having a section suited to the aircraft (20); - a plurality of horizontal guide blades (8) and vertical guide blades (9) responsible for varying the direction of the generated laminar air current to perform a lateral and vertical control of said air current, respectively. 3. The system according to any of the preceding claims, characterized in that the airflow control means comprise: - sensor means responsible for obtaining the conditions of the laminar air current and the state of the air potential generating means and the laminar airflow generating means; - control means configured for controlling the air potential generating means and the laminar airflow generating means depending on control signals; - data processing means responsible for generating said control signals in real time, depending on the information supplied by the sensor means, in cooperation with the flight control system of the aircraft and with the interaction logic, depending on its approach conditions and the trajectory calculation by the control hardware housing the interaction logic. 4. The system according to any of the preceding claims, characterized in that the aircraft collecting and immobilizing means comprise: - a landing platform (10) which can be lifted by means of an articulated mechanism (11); - lifting means of the landing platform (10) responsible for lifting the landing platform (10) and bringing it closer to the aircraft (20) when it is in the collection area; - fixing and anchoring device responsible for immobilizing the aircraft in the collection area; - sensor means responsible for establishing the position of the fixing and anchoring device and the position of the aircraft (20); - control unit configured for controlling the lifting means of the landing platform (10) and the actuation of the fixing and anchoring device, following the command generated by the interaction logic, in real time and in cooperation with the airflow control systems of the aircraft, depending on the position of the aircraft (20) and on the conditions of the generated current. 5. The system according to claim 4, characterized in that the fixing and anchoring device comprises a battery of electromagnets arranged in the landing platform (10). 6. The system according to claim 5, characterized in that the fixing and anchoring device comprises a mechanical fixing of the landing gear of the aircraft (20). 7. The system according to any of the preceding claims, characterized in that the trajectory generating means comprise a first GPS unit in the not-on-board installation (13) and data processing means configured for: - receiving the GPS position from the first GPS unit; - receiving the GPS position of the aircraft (20) from a second on board GPS unit; - receiving the altitude of the aircraft (20) from an altimeter on board the aircraft; - generating the trajectory depending on at least: • the readings from the first and second GPS units; • the reading from the on board altimeter; • the reading from the on board and not-on-board air sensors. 8. The system according to any of the preceding claims, characterized in that it comprises a platform (1) responsible for supporting the not-on-board installation (13). 9. The system according to any of the preceding claims, characterized in that the installation on board the aircraft (20) additionally comprises immobilizing and anchoring means compatible with the aircraft collecting and immobilizing means of the not-on-board installation (13) to jointly immobilize the aircraft (20) in the collection area. 10. The system according to the preceding claim when it depends on claim 5, characterized in that the immobilizing and anchoring means of the installation on board the aircraft (20) comprise: - a landing gear compatible with the aircraft collecting and immobilizing means of the not-on-board installation (13); - a battery of electromagnets geometrically compatible with the electromagnets of the aircraft collecting and immobilizing means of the not-on-board installation (13); - a control unit responsible for controlling the intensity of the electric current powering the battery of electromagnets of the aircraft (20) depending on the position of the aircraft during the guiding maneuver and on the control commands generated by the interaction logic. 11. A method to assist conventional fixed-wing aircraft (20) landing without a runway, characterized in that it comprises: - generating an adjustable laminar air current directed against the forward movement of the aircraft (20) by means of a not-on-board installation (13); - calculating an approach and collection strategy of the aircraft in real time by means of interaction logic, in cooperation with the airflow control system and the aircraft control system; - providing the definition of the trajectory which must be followed by the aircraft (20) to be guided to the collection area to the glide slope generating means in real time and adapting it to the conditions of the maneuver by means of the interaction logic; - providing the strategy which must be followed by the flight control system of the aircraft (20) to be guided to the collection area to the on board installation in real time and adapting it to the conditions of the maneuver by means of the interaction logic; - obtaining the approach conditions of the aircraft (20) in the not-on-board installation (13), in the on board installation and in the interaction logic; - controlling the laminar air current with the suitable conditions to maintain the airworthiness of the aircraft (20) depending on the approach conditions of the aircraft (20) and on the result from executing the interaction logic; - controlling the aircraft (20) to follow the generated glide slope depending on the conditions of the laminar air current and on the result from executing the interaction logic; - immobilizing the aircraft (20) in the collection area once the aircraft has reached said collection area by means of aircraft collecting and immobilizing means.