This invention relates to a flight data recording device and a flight data recording method in a light aircraft.

Most commercial aircraft, in particular commercial airplanes, include a Flight Data Recorder commonly known by the corresponding acronym FDR. An FDR notably allows performing a post-flight analysis which may then be used in order to improve the pilot’s technique. Also, the FDR may be used for accident and incident investigation. In both cases, the FDR improves safety aboard the aircraft. An FDR is a system connected to the aircraft’s avionics in order to collect and record flight data. Usually, an FDR is provided by the manufacturer and installed for the whole life of the aircraft.

Light aircraft’s manufacturers do not offer to equip their aircraft with an FDR. The only way to have an FDR in a light aircraft is to install an FDR provided by a different supplier. However, installing an FDR requires connecting it to the aircraft’s avionics . This may be rendered difficult if the aircraft’s avionics is incompatible with the FDR or if the aircraft has analogous flight instruments. Anyhow, it involves a long installing step, usually lasting more than 30 hours, and both equipment and installation are costly.

Furthermore, light aircraft’s pilots change frequently the aircraft or aircraft model they pilot. This involves repeating numerous times the above-mentioned installation step .

For these reasons, light aircraft are often not equipped with an FDR and do not enj oy the same safety level as commercial aircraft.

It is thus an object of the invention to provide a flight data recording device adapted to a light aircraft.

According to a first aspect of the invention, it is proposed a flight data recording device for a light aircraft including a sensing means able to issue a signal representative of an aircraft-related data, a data processing unit configured to process a signal issued by the sensing means .

According to one of its general features, this device further includes an autonomous electric energy supply means .

By virtue of these features, the invention provides an energetically autonomous flight data recording device. This limits the need for a connection between the aircraft and the device. The installation of the device is thus rendered simpler, especially when compared with the 30 hours long lasting installation process of existing FDR .

Preferably, the autonomous electric energy supply means includes a battery and a recharging means .

In a preferred embodiment, the recharging means includes a cigarette-lighter connector.

Such a connector allows recharging easily the device in most light aircraft.

In another embodiment, the autonomous electric energy supply means includes an output connector and an electrical charge management system so configured to allow the providing of electric energy to an apparatus via the output connector if a remaining supplying time of the autonomous electric energy supply means is upper than a threshold.

Such features allow recharging an electronic apparatus of an occupant of the aircraft such as the pilot’s mobile phone while ensuring that the device remains available until the end of flight.

Several variants are possible for choosing the above-mentioned threshold.

According to a first variant, the threshold is included within a range of 2 to 4 hours .

Such a range matches with average flight remaining durations in light aircraft. In this variant, the threshold may be set using little calculation resources . According to a second variant, the electrical charge management system is so configured to determine the threshold taking into account a flight remaining duration of the light aircraft.

In this variant, the threshold is adapted to the real flight remaining duration so as to allow recharging of an occupant’s electronic device while ensuring a maximal availability of the device.

It may also be foreseen a calculation unit able to determine a flight remaining duration from a flight plan of the light aircraft.

Preferably, it is foreseen a reception unit able to receive a flight plan and a calculation unit able to determine a flight remaining duration from a flight plan received by the reception unit.

In another embodiment, the aircraft-related data is chosen among an acceleration of the aircraft, a heading of the aircraft, an attitude of the aircraft, a three-dimensional position of the aircraft, a vertical speed of the aircraft, a ground speed of the aircraft, an indicated air speed of the aircraft, a vibration felt in the cockpit, an engine rotational speed, a temperature inside the cockpit, an outside air temperature, a humidity inside the cockpit, an outside humidity, an atmo sphere composition inside the cockpit, an outside atmosphere composition, an oxygen partial pressure and a carbon monoxide fraction inside the cockpit.

Preferably, the carbon monoxide fraction inside the cockpit is a carbon monoxide volume fraction.

Preferably, the sensing means includes at least one sensor cho sen among an inertial unit, an altitude and heading reference system, an accelerometer, a gyroscope, a magnetometer, a global navigation satellite system, a Pitot tube, a microphone, a temperature sensor, an hygrometry sensor, a gas detector, an oxygen sensor and a camera.

One may also foresee a memory in data connection with the data processing unit, the memory being able to record a signal issued by the sensing means and/or a signal processed by the data processing unit.

Such a memory allows performing a post-flight analysis. Preferably, the memory is contained in a crashproof compartment.

By virtue of this feature, a po st-flight analysis is possible even if a crash of the aircraft occurs.

One may also foresee a recognition means able to issue a signal representative of the model of the light aircraft.

Also , one may foresee a recognition means able to issue a signal representative of the identification number of the light aircraft.

The recognition means improves the portability of the device by allowing to adapt the device to aircraft being of different models or different instances of the same model. Therefore, a pilot may use the same device even when piloting different aircraft, without it changing the safety contribution provided by the device.

Preferably, the recognition means includes an entry terminal . Thus, the pilot may enter the model or the identification number of the light aircraft he is piloting . It is provided a simple way, requiring little action from the pilot, to recognize the model or the identification number of the light aircraft.

In another embodiment, the recognition means may include a tag reader able to recognize a tag, preferably a near field communication (NFC) tag, installed inside the aircraft. In such case, the tag reader communicates with the tag using a wireless technology such as NFC.

Preferably, the sensing means further includes a physiological sensor able to issue a signal representative of a physiological data of an occupant of the light aircraft.

Supervising the occupants, in particular the pilot, is crucial in light aircraft because most light aircraft’s pilots have less experience than commercial aircraft’s pilots and often fly without a co-pilot. The physiological sensor thus renders the device even more adapted to a light aircraft.

There is a synergy effect when a physiological sensor and a recognition means are foreseen. Indeed, since the device equipped with a physiological sensor adapts itself to the pilot, the pilot is all the more interested to use a same device when piloting different types of light aircraft.

Preferably, the physiological data is chosen among a heart rate, a heart rate variability, a blood pressure, a pulse oximetry, a respiratory rate, a skin conductance level, a skin conductance response, a skin temperature, an electroencephalogram power spectrum, an eye blink, a point of gaze, an eye motion, a pupil dilatation, a position and/or a movement of a hand of an occupant of the aircraft, a position and/or a movement of a head of an occupant of the aircraft and a face expression.

In an advantageous manner, the physiological sensor is chosen among an electrocardiography sensor, a photoplethysmography sensor, a pulse oximeter, a piezoelectric respiratory belt, an electrodermal activity sensor, a bioimpedance sensor, an electroencephalography sensor, a functional near-infrared spectroscopy sensor, an inertial measurement unit and an oculometry sensor.

One may also foresee an ARINC port.

Such a port facilitates the collection of aircraft-related data by allowing to connect with the avionics .

In an embodiment, the ARINC port is an ARINC 429 port.

In another embodiment, the ARINC port is ARINC 7 17 port.

Such ports are particularly adapted for collecting data from the avionics and/or from a digital flight data recorder of the aircraft.

It may also be foreseen a data transmission means able to transfer a signal issued by the sensing means and/or a signal processed by the data processing means .

Preferably, the data transmission means includes at least one module chosen among a Wi-Fi module, a Bluetooth module, a GSM module, a satellite telecommunication module, a WiMax module, a Z- wave module, a Sigfox module, a LoraWAN module, a VHF module and an NFC module.

According to another aspect of the invention, it is proposed a method of recording flight data in a light aircraft including providing a device as set forth above with electrical energy supplied by an autonomous electric energy supplying means, issuing a signal representative of an aircraft-related data and processing the signal issued.

Other advantages and features of the invention will emerge upon examining the detailed description of embodiments, which are in no way limiting, and the appended drawings wherein:

- figure 1 is a top-down schematic view of a light aircraft including a flight data recording device according to a first embodiment of the invention,

- figure 2 is a flowchart of the flight data recording device of figure 1 ,

- figure 3 illustrates a physiological sensing unit of the device of figure 2,

- figure 4 illustrates an inside-atmosphere sensing unit of the device of figure 2,

- figure 5 is a flowchart of a flight data recording device according to a second embodiment of the invention,

- figure 6 is a flowchart of a flight data recording device according to a third embodiment of the invention, and

- figure 7 is a flowchart of a flight data recording device according to a fourth embodiment of the invention.

As illustrated in figure 1 , a light aircraft 2, in particular a light airplane, includes a propulsion engine 4, a battery 6, an aircraft computer 8 and a cockpit 10. In the schematic view of figure 1 , a pilot 12 and a passenger 14 are installed in the cockpit 10. The passenger 14 uses an electronic device 16, which may be for instance a mobile phone or a laptop .

The aircraft 2 further includes a machine-related sensor 18 , a positional sensor 20 and an atmo sphere sensor 22. The sensor 1 8 is able to detect machine-related data which is data concerning the equipment of the aircraft 2. In the embodiment of figure 1 , the sensor 18 detects an engine speed of the engine 4 and a vibration felt in the cockpit 10. The sensor 20 is able to detect positional data of the aircraft 2. In the embodiment of figure 1 , the sensor 20 detects acceleration, heading, attitude, three-dimensional position, vertical speed, ground speed and indicated air speed of the aircraft 2. The sensor 20 may include an inertial unit, a global navigation satellite system and a Pitot tube. The sensor 22 detects an atmosphere-related data being namely an outside air temperature, an outside humidity and an outside atmosphere composition. The sensors 18 , 20 and 22 are in data connection with the aircraft computer 8. The location of the sensors 18 , 20 and 22 on the schematic drawing of figure 1 is not limitative. Although the sensors 18 , 20 and 22 are depicted at the various locations of the aircraft 2, one or all of these sensors may be a part of the aircraft computer 8.

The aircraft 2 further includes a flight data recording device 24 which will now be described referring to the flowchart of figure 2. The flight data recording device 24 includes a crashproof compartment 26. The crashproof compartment 26 is so designed to prevent damages caused to devices contained therein in case of a crash of the aircraft 2. The crashproof compartment 26 is schematically represented on figure 2 by a rectangle. The devices located within the rectangle on figure 2 are contained in the crashproof compartment 26.

The flight data recording device 24 further includes a sensing means 28. The sensing means 28 includes two physiological sensing units 30 and 32. The physiological sensing units 30 and 32 are respectively installed proximate to the pilot 12 and the passenger 14. The physiological sensing units 30 and 32 include a plurality of sensors able to detect physiological data concerning, respectively, the pilot 12 and the passenger 14. In the depicted embodiment, the physiological sensing units 30 and 32 are identical. Nevertheless, one may imagine different physiological sensing units . Although, in the depicted embodiment, it is foreseen a physiological sensing unit for each occupant of the aircraft 2, one may imagine, without departing from the scope of the invention, an embodiment wherein a physiological sensing unit is provided for only one occupant, for instance the pilot 12. The physiological sensing unit 30 is depicted on the schematic view of figure 3. The physiological sensing unit 30 includes an electrocardiography sensor 34, a photoplethysmography sensor 36, a pulse oximeter 38 , a piezoelectric respiratory belt 40, an electrodermal activity sensor 42, a bioimpedance sensor 44, an electroencephalography sensor 46 , a functional near-infrared spectroscopy (FNIRS) sensor 48 , an oculometry sensor 50, two inertial measurement units 5 1 and 53 and a camera 52. In the first embodiment, the sensors 36 , 38 , 42, 44 and 5 1 are installed next to an arm, a wrist, a hand or fingers of the pilot 12. The sensors 34 and 40 are placed near a chest of the pilot 12. The sensors 46 , 48 and 53 are placed near a head of the pilot 12. The inertial measurement units 5 1 and 53 allow metering the position and the movement of the pilot 12’ s hand and head. Namely, the inertial measurement units 5 1 and 53 provide data including 3-axis gyro scopic data and a 3 -axis magnetometry. One may also foresee a supplementary inertial measurement unit on the pilot 12’ s chest in order to provide a reference for the inertial measurement units 5 1 and 53. The sensor 50 is placed in glasses worn by the pilot 12. Without departing from the scope of the invention, one may foresee that the sensors 36 and 38 are placed near the pilot 12’s chest or head or that the sensor 50 is placed on the dashboard of the cockpit 10. The camera 52 faces the pilot 12' s head.

By virtue of the sensing units 30 and 32, a physiological data related to the pilot 12 and the passenger 14 may be detected. Namely, the physiological data includes heart rate, heart rate variability, blood pressure, pulse oximetry, respiratory rate, skin conductance level, skin conductance response, electroencephalogram power spectrum in different frequency bands and using different cranial locations, eye- blinking, a point of gaze, eye motion, pupil dilatation, position and movement of different body parts and face expression. The physiological sensing units 30 and 32 allow monitoring a physiological state of the occupants 12 and 14 of the light aircraft 2, in particular a physiological state of the pilot 12, thus increasing on one hand the liability of the detection in real time of hazardous situations and on the other hand the liability of the post-flight analysis

Referring to figure 2, the sensing means 28 includes an ARINC 429 port 54 and an ARINC 7 17 port 56. The ports 54 and 56 implement a data connection between the device 24 and the sensors 1 8 , 20 and 22. As a consequence, the sensing means 28 may collect aircraft-related data, including machine-related data detected by the sensor 18 and positional data detected by the sensor 20. Namely, the sensing means 28 collects three-dimensional acceleration, heading, attitude, three- dimensional position, vertical speed, ground speed and indicated air speed of the aircraft 2, vibrations felt in the cockpit 10 and speed of the engine 4. Besides, the sensing means 28 may collect atmosphere- related data detected by the sensor 22. Namely, the sensing means 28 collects temperature, humidity and oxygen partial pressure of the air outside the cockpit 10.

In the depicted embodiment, the sensing means 28 are part of the aircraft 2 and are in data communication with the sensors 18 , 20 and 22 via the aircraft computer 8. Nevertheless, in particular if the aircraft does not include an aircraft computer, the sensors 1 8 , 20 and 22 may be in direct data communication with the sensing means 28.

Also, the sensors 18 , 20 and 22 may be part of the sensing means 28 instead of being part of the aircraft 2.

The sensing means 28 includes a camera 57 facing the instrument panel inside the cockpit 10. By means of the camera 57 , the sensing means 28 may extract values displayed on the gauges and instruments of the instrument panel.

The sensing means 28 includes a microphone 60. The microphone 60 is located inside the cockpit 10 and collects an ambient sound within the cockpit 10. The sensing means 28 also includes a microphone 67 connected to a multiplexer (not depicted) between the pilot 12’s headphones and a radio (not depicted) . Then, the microphone 67 may detect communication passing via the headphone and the radio, being namely communication between the occupants 12 and 14 and communication to and from a control tower. The sensing means 28 includes an inside-atmosphere sensing unit 61 . The inside atmosphere sensing unit 61 is installed inside the cockpit 10. The inside-atmosphere sensing unit 6 1 includes a plurality of sensors able to detect inside-atmo sphere data concerning the air inside the cockpit 10. The inside-atmosphere sensing unit 61 is depicted on the schematic view of figure 4.

The sensing unit 61 includes a thermometer 62, a hygrometer 63 , a gas detector 64 and an oxygen sensor 65. By virtue of the sensing unit 61 , an inside-atmo sphere data related to the air inside the cockpit 10 may be detected. Namely, the inside-atmosphere data includes temperature, humidity, oxygen partial pressure and carbon monoxide volume fraction of the air inside the cockpit 10.

The device 24 further includes a recognition means 66. The recognition means 66 is intended to recognize a type of the aircraft 2. In the first embodiment, the recognition means 66 includes an entry terminal 68. The pilot 12 enters the type of the aircraft 2 in the entry terminal 68.

The device 24 includes a data processing unit 70. The data processing unit 70 is in data connection with the sensing means 28. Hence, the data processing unit 70 processes data collected by the sensing means 28. The data processing unit 70 is also in data connection with the recognition means 66. The data processing unit 70 takes into account a type of the aircraft 2 recognized by the recognition means 66 when processing the data collected by the sensing means 28.

The data processing unit 70 includes a filtering module 72, an automatic learning module 74, a state machine module 76, an image recognition module 78 able to recognize elements in a video flow, a face expressions recognition module 80, a speech recognition module 82 and a data fusion module 84. By means of the modules 72 to 84, the data processing unit 70 is able to combine data collected by the sensing means 28 in order to determine an outstanding situation encountered by the aircraft 2, the pilot 12 or the passenger 14. The device 24 includes an air-air data transmission means 86 in data connection with the sensing means 28 and in data connection with the data processing means 70. The data transmission means 86 is able to transmit data collected by the sensing means 28 and data processed by the data processing unit 72 to an external device such as a computer or a mobile phone. In the first embodiment, the data transmission means 86 is a Wi-Fi module. As a consequence, the data collected by the sensing means 28 and processed by the data processing unit 70 may be easily outputted to an external device via a Wi-Fi connection, preferably during a post-flight stage.

Nevertheless, one may without departing from the scope of the invention replace the Wi-Fi module with another wireless short distance data transmission means, such as a Bluetooth module, a Bluetooth Low Energy module, a Z-wave module, an ANT+ module, an NFC module, a WiMAX module, a Zigbee module or a LoraWAN module.

The device 24 further includes a memory 88 , for instance an SD card, in data connection with the sensing means 28 and with the data processing unit 70. As a consequence, the memory 88 may store data issued by the sensing means 28 and by the data processing unit 70. The memory 88 is located within the crashproof compartment 26. Hence, if a crash of the aircraft 2 occurs, the memory 88 may be removed from the crashproof compartment 26 in order to extract data stored therein. Flight data stored before the crash may thus be collected.

The device 24 includes a locator beacon 90. In the depicted embodiment, in order to improve even more safety, the locator beacon 90 is contained in the crashproof compartment 26.

The device 24 further includes an autonomous electric energy supply means 92. The autonomous electric energy supply means 92 is in electrical connection with the means 28 , the means 66, the unit 70, the means 66 and the memory 88. The autonomous electric energy supply means 92 includes a battery 94 and a solar panel 96. The battery 94 is so designed that, when it is at full charge, the autonomous electric energy supply means 92 may supply enough electric power to operate the device 24 during 5 to 7 hours . Hence, the device 24 may operate properly during the whole duration of a typical flight implemented by a light aircraft. Despite that, in the depicted embodiments, two different electric energy sources are foreseen in the means 92, one may foresee only one of those electric sources and/or foresee another electric energy source.

The autonomous electric energy supply means 92 includes a recharging means 98. The recharging means 98 is intended to allow reloading the battery 94. In the depicted embodiment, the recharging means 98 includes a cigarette-lighter connector 100. Hence, the cigarette-lighter connector 100 may be plugged in a corresponding connector located in the cockpit 10 so as to connect electrically the battery 94 with the battery 6. Nevertheless, the connector 100 may be of a different type, such as a USB connector. Electrical energy may thus be provided to the battery 94.

The autonomous electric energy supply means 92 further includes an output connector 102. In the depicted embodiment, the output connector 102 is a USB connector. The electronic device 16 or another electronic device may be plugged on the connector 102 and electric energy may be transferred from the autonomous electric energy supply means 92 to the electric device 16. Without departing from the scope of the invention, one may foresee an output connector 102 being different from a USB connector. Also, one may foresee supplementary output connectors .

The autonomous electric energy supply means 92 includes an electrical charge management system 104. The electrical charge management system 104 includes an estimating unit 106 able to estimate the remaining supplying time t _{r e m} aini ng · The time t _{r e m} aini ng corresponds to the duration until the moment where the autonomous electric energy supply means 92 cannot provide electrical energy anymore . The electrical charge management system 104 includes a comparator 108 collecting the time t _{r e m} ai ning estimated by the estimating unit 106. The comparator 108 compares the time t _{r e m} ai ning with a threshold ti. In the embodiment depicted on figure 2, the threshold ti is a predefined value within a range 2 hours to 4 hours.

If the time t _rem aining is lower than the threshold 11 , the electrical charge management system 104 prevents electric energy supply via the output connector 102. On the contrary, the electrical charge management system 104 authorizes electric energy supply via the output connector 102 if the time t _rem aining is higher than the threshold ti. This allows preserving electric energy for operating the device 24 in order to improve security of the occupants of the aircraft 2, while allowing to use electric energy for recharging other devices if the amount of electrical energy stored in the battery 94 is sufficient.

Figure 5 illustrates a flight data recording device 110 according to a second embodiment of the invention. The same elements have the same references.

The flight data recording device 110 differs from the device 24 in that it includes a reception unit 112 being in data connection with the aircraft computer 8. The reception unit 112 is able to receive a flight plan followed by the aircraft 2 and entered in the aircraft computer 8.

The device 110 includes a calculation unit 114 in data connection with the reception unit 112. The calculation unit 114 is so configured to calculate a flight remaining duration d _rem aining from a flight plan received by the reception unit 112. The calculation unit 114 is so configured to replace the threshold ti of the comparator 108 if a duration d _rem aining has been calculated.

Hence, if no flight plan has been entered, the comparator 108 uses the threshold ti. If a flight plan has been entered in the aircraft computer 8, the threshold ti stored in the comparator 108 is replaced by the duration d _rem aining calculated by the calculation unit 114.

Although, in the depicted embodiment, the duration d _rem aining is inferred from a data communication with the aircraft computer 8, one may foresee a data communication with another device, for instance a navigation application of the pilot 12. Such a data communication is particularly advantageous because it allows issuing a duration d _remaining even if the pilot has not entered his whole flight plan in the aircraft computer 8 or in the automatic pilot of the aircraft 2.

Figure 6 illustrates a flight data recording device 1 16 according to a third embodiment of the invention. The same elements have the same references .

The device 1 16 differs from the device 24 in that the recognition means 66 does not include an entry terminal 68. The recognition means 66 is in data connection with the aircraft computer 8 and with the data processing unit 70. Hence, the recognition means 66 is able to infer a type of the aircraft 2. For instance, the recognition means 66 may infer from pictures of the instrument panel a model and an identification number of the aircraft, using the image recognition module 78.

As a variant, the recognition means 66 may include a tag reader able to recognize an NFC tag installed inside the aircraft 8.

Figure 7 illustrates a flight data recording device 1 18 according to a fourth embodiment of the invention. The same elements have the same references .

The flight data recording device 1 18 differs from the device 24 in that the data transmission means 86 includes a telecommunication external antenna 120. Besides, the data transmission means 86 is able to transmit data by satellite telecommunication using a constellation such as Iridium, Inmarsat, Globalstar.

By virtue of this design, the device 1 1 8 may transmit data in real time to a distant control centre (not depicted) being for instance on the ground. This allows detecting in real time outstanding situations requiring a specific response, such as a customized alert by an operator of the distant control centre.

Although the data transmission means 86 of the device 1 18 uses a telecommunications satellite technology, one may without departing from the scope of the invention foresee a different kind of long range transmission such as a GSM module, a WiMax module, a SigFox module and a VHF module .