EP2198249A1

EP2198249A1 - Backup instrument for aircraft

Info

Publication number: EP2198249A1
Application number: EP08804753A
Authority: EP
Inventors: Pierre Idrac
Original assignee: Thales SA
Current assignee: Thales SA
Priority date: 2007-10-05
Filing date: 2008-09-25
Publication date: 2010-06-23
Also published as: FR2922011B1; FR2922011A1; CA2701629A1; WO2009043806A1; CN101849163A

Abstract

The invention relates to a backup instrument (4) that can be fitted in the dashboard of an aircraft. The backup instrument (4) includes means (11, 25, 28) for calculating and displaying backup flight information from backup signals provided by the backup equipment (20, 21, 22, 23, 24) of the aircraft, a memory (29) and means (30) for storing during normal operation the backup flight information and/or the backup signals in the memory (29) of the backup instrument (4). The invention makes it easier to identify the circumstances and causes of an aircraft accident in that it provides flight information independent from the aircraft's primary systems.

Description

Aircraft rescue instrument

The invention relates to a backup instrument integrated on the dashboard of an aircraft for displaying essential flight information in the event that primary systems fail.

Conventionally, an aircraft is equipped with primary systems for determining and displaying information necessary for its management. The primary systems include inertial sensors and pressure sensors connected to total and static pressure taps located on the skin of the aircraft. The primary signals delivered by the inertial sensors and the pressure sensors are processed by an onboard computer which sends the processed data to primary display systems. The primary display systems include primary display screens integrated on a dashboard of the aircraft. The primary visualization screens are doubled, one group of primary visualization screens being intended for the pilot and the other group for the co-pilot. Each group generally comprises a screen presenting flight information such as the speed, altitude and attitude of the aircraft and a screen presenting navigation information such as the route to be followed and instructions for automatic flight control. aircraft.

In addition, to be able to determine and explain the circumstances and causes of an accident or incident on an aircraft, it may be equipped with flight recorders, sometimes called "black boxes". The installation of these flight recorders is mandatory in airliners. There are currently two types of flight recorders, the first being a voice recorder called CVR, the acronym for the English phrase "Cockpit Voice Recorder", the second being a flight parameter recorder called FDR, acronym for Anglo-Saxon expression "Flight Data Recorder". The voice recorder is used for recording radio communications, voice and room noise from the cockpit, such as noise from motors or alarms. This data is recorded for example in a loop, over thirty to one hundred and twenty minutes. In particular, four magnetic stripe tracks can be used to the recording of these data, the tracks being for example distributed as follows:

- radio communications on tracks 1 and 4,

- communications with the cabin crew on track 1, - communications with the ground mechanic on tracks 1, 2 and 4,

- room microphone on track 3.

The FDR is used to record, on the one hand, the parameters of the aircraft, such as the operation of engines, an autopilot, the position of control surfaces and flight controls, and secondly, flight information displayed by the primary display screens, such as the speed, altitude and attitude of the aircraft. Depending on the age and type of the aircraft, more than a thousand different flight settings and information may be recorded. In some cases, it is possible to perform a computer simulation of the flight from the parameters and flight information recorded in the FDR. This data is for example recorded in a 25-hour loop, which is the minimum regulatory time. The FDR is connected to the various computers and sensors of the aircraft through an acquisition box, known as the "FDAU", acronym for the English expression "Flight Data Acquisition Unit". The FDAU is in particular responsible for selecting the parameters and the flight information to be recorded in the FDR and for ordering them to send them to the FDR in a continuous frame. This frame is formed of 12-bit words, sent at a rate of 64 to 1024 words per second, depending on the type of the aircraft. The FDR then records this frame directly into its memory. The content of the frame must meet requirements defined by national and / or international regulations. In particular, the list of parameters and flight information to be recorded, as well as their recording rate and the required accuracy are specified.

Flight recorders are designed to ensure that the memories containing the recorded data, including, but not limited to, radiocommunications, communications with the cabin crew, cockpit noise, aircraft parameters and flight information are protected during an incident or an accident on the aircraft. In particular, flight recorders must withstand an acceleration of 3400 g for 6.5 milliseconds, at a temperature of 1100 degrees Celsius for one hour and at a depth of at least 5000 meters. However, flight recorders are sometimes very damaged. All data to determine the circumstances and causes of the incident or accident of the aircraft are therefore not always available for an investigation of the incident or accident. In particular, in the event of complete destruction of the flight recorders, only the information recorded on the ground by the air traffic control may be used for the investigation. Data recovery is also conditioned by their registration. A failure of the primary systems prevents the recording in the FDR of flight information and aircraft parameters. This is particularly the case when a pressure point, a sensor or the on-board computer fails. More generally, existing solutions have the disadvantage of having only one source of information and store this information in a single storage location.

An object of the invention is in particular to overcome all or part of the aforementioned drawbacks. For this purpose, the subject of the invention is an emergency instrument capable of equipping an instrument panel of an aircraft, the emergency instrument comprising means for calculating and displaying emergency flight information from emergency signals provided. by emergency equipment of the aircraft, characterized in that it comprises a memory and means for recording in normal operation the emergency flight information and / or spare signals in the memory of the standby instrument.

Emergency instruments are used, but not exclusively, in the event of failure of the primary systems. For this purpose, an emergency instrument presents essential information for the piloting of the aircraft, in particular the speed, the altitude and the attitude of the aircraft. This essential information, called emergency flight information, alone can control the aircraft.

Previously, the information presented by the standby instruments was obtained and displayed by electromechanical. These have been replaced by electronic instruments, which has resulted in weight gains, size and reliability. Greater flexibility of use is also obtained since it is possible to add other information. In particular, some backup instruments combine, in addition, altitude, speed and attitude information, navigation information.

A rescue instrument must also be autonomous and decorrelated from the other instruments on board. For this purpose, it integrates equipment, for example sensors, to generate the information it provides. Thus, it comprises pressure sensors connected to total and static pressure taps located on the skin of the aircraft. The pressure sensors make it possible in particular to define the altitude and the speed of the aircraft. It can also include an inertial unit, several temperature sensors and other types of sensors. The display screen of the standby instrument can be in liquid crystal technology.

In addition to the information generated directly in the standby instrument, the latter can receive information from other systems on the aircraft. This information passes for example on a serial bus of the aircraft, known under the term "ARINC", with reference to a digital data transmission standard known as the ARINC standard (Aeronautical Radio Incorporation). This data can for example indicate the course of the aircraft and are therefore displayed on the screen of the standby instrument.

The standby instrument can also send information to the outside, in particular to an autopilot of the aircraft. Indeed, since it itself generates some of the information it displays, it can provide this information to other systems integrated into the aircraft. In particular, the autopilot needs reliable information. For example, the primary systems of an aircraft comprise at least two inertia sensors. However, these sensors may fail or deliver false information. In this case, the standby instrument can compensate for the faulty sensor and / or indicate which of the two sensors provides the correct information. For an autopilot, it is therefore particularly important to have at least three pieces of information for the same parameter. By construction, different instruments can be interconnected but there is always a segregation between the primary systems and the backup instruments.

The main advantage of the invention is that it makes it possible to have the flight information determined by the emergency instrument independently of the primary systems and the flight recorders. In particular, it makes it possible to have the flight information determined by the emergency instrument even in the event of failure of one of the elements of the primary systems or the FDR. The invention also facilitates the determination of the circumstances and causes of the incident or accident of an aircraft by recording the flight information in a different location of the FDR, in this case in a memory of the aircraft. rescue instrument. Flight information can remain available even if the FDR is destroyed.

The invention will be better understood and other advantages will become apparent on reading the detailed description of an embodiment given by way of example, a description given with regard to the appended drawings which represent:

- Figure 1, a dashboard of an aircraft equipped with a backup instrument;

FIG. 2, an example of information displayed by the standby instrument; - Figure 3, by a block diagram, an exemplary embodiment of a standby instrument;

- Figure 4, a memory of the standby instrument according to the invention.

Figure 1 schematically shows a dashboard 1 of an aircraft, for example an airliner. Dashboard 1 comprises means for calculating and displaying primary flight information from primary signals provided by primary equipment of the aircraft. For example, it includes two groups of display screens 2, 3. Each group includes a screen including primary flight information such as altitude, speed and attitude of the aircraft and a screen with navigation information. The two groups 2, 3 are identical, one being reserved for a pilot and the other for a co-pilot. These two groups form primary visualization screens. The primary display screens are connected to an on-board computer including primary signals delivered by primary equipment to calculate the primary flight information and navigation information. The primary equipment includes inertial sensors and pressure sensors connected to total and static pressure taps located on the skin of the aircraft. The set comprising the primary equipment, the on-board computer and the primary display screens is called primary systems. An emergency instrument 4 is placed between these two groups 2, 3 of primary visualization. Optionally, it is possible to provide several backup instruments. The standby instrument 4 of FIG. 1 has at least altitude, speed and attitude information of the aircraft.

FIG. 2 presents a backup instrument 4, of the electronic type, equipping an aircraft. The standby instrument 4 comprises a housing 10 and display means. The display means comprise, for example, a liquid crystal screen 1 1 forming the front face of the standby instrument 4 and displaying emergency flight information, namely the attitude, the speed and the altitude of the aircraft. A first zone 12 of the screen 1 1 presents the attitude of the aircraft symbolized by its wings 13 with respect to a skyline 14. A second zone 15 displays the speed of the aircraft and a third zone 16 displays the altitude of the aircraft. In addition to these three essential information, other information can be presented on the same page. In the example of FIG. 2, an area 17 is reserved for heading information. By pressing a specific button 18, another page may be displayed to present for example navigation information or other information. In case of failure to display the primary display screens 2, 3, the screen 1 1 of the standby instrument 4 is then used by the pilot and the co-pilot to display the emergency flight information. FIG. 3 illustrates a backup instrument 4 by a block diagram. The standby instrument 4 comprises emergency equipment, for example two pressure sensors 20, 21 connected to static and total pressure taps 22 located on the skin. of the aircraft and an inertial sensor 24. These different sensors 20, 21, 24 may be located outside or inside (as shown in Figure 3) of the emergency instrument 4. In all cases , the emergency equipment 20, 21, 22, 23, 24 are independent of the primary systems. The pressure sensors 20, 21 make it possible to generate altitude and speed information of the aircraft, while the inertial sensor 24 makes it possible to generate attitude information of the aircraft. The information provided by these sensors 20, 21, 24 arrives at processing means 25, which exploit the emergency signals from the sensors 20, 21, 24 and possibly initialization parameters, for example entered by the pilots, to generate the altitude, speed and attitude information of the aircraft. The processing means 25 may also receive information provided by other systems via a bus 26, for example an ARINC bus. In particular, the processing means 25 can receive flight information and navigation information from the primary systems 27. The processing means 25 can also generate information for transmission to the outside, for example via the bus 26, to destination including the autopilot. The emergency flight information calculated by the processing means 25 and, if appropriate, the information provided by the other systems are sent to the display means 28 so as to be displayed on the screen 11 of the flight instrument. 4. The backup instrument 4 may also include a memory 29 managed by memory management means 30. The memory 29 is for example internal to the backup instrument 4. It allows in particular to store the initialization parameters and computer programs for processing emergency signals from the sensors 20, 21, 24 and calculating the emergency flight information. The memory is accessible in reading and writing.

According to the invention, the backup instrument 4 may also include means for recording in normal operation the rescue flight information. In particular, the memory 29 is also used to record in normal operation the emergency flight information generated by the emergency equipment 20, 21, 22, 23, 24 and the processing means 25. According to another embodiment of the invention, another memory, physically distinct from the memory 29, can also be used to record the rescue flight information. The emergency flight information is automatically recorded throughout the flight of the aircraft, without the intervention of the pilot, the flight of the aircraft being understood as the period during which the emergency instrument 4 or the primary systems 27 are powered. The emergency flight information is for example recorded in such a way that it can be re-displayed later. Advantageously, this flight information corresponds to the flight information used for the display on the screen 1 1 of the rescue instrument 4. It is thus possible, after a flight, to retrieve and analyze the flight information of provided to the pilot during the flight. In one embodiment, the re-display of the saved emergency flight information is done on the screen 1 1 of the standby instrument 4, for example by means of the memory management means 30, the processing means 25 and display means 28. This embodiment has the advantage of being able to analyze the emergency flight information as it was actually presented to the pilot during the flight, the display that the pilot saw during the flight being in so regenerated. It is thus possible to detect a possible failure of the standby instrument 4, whether this failure is due to the processing means 25 or to the display means 28.

In a particular embodiment, the memory 29 is an electrically erasable and programmable read-only memory, called EEPROM, an acronym for the "Electrically Erasable Programmable Read OnYy Memory". This type of memory allows an infinite number of readings of the contents of the memory and can be reprogrammed more than a million times. It has the particular advantage of not requiring power supply for the storage of data stored in memory. This type of memory is therefore particularly suitable for storing initialization parameters and computer programs and in particular flight information. emergency, the power supply means of the aircraft being generally out of use in the event of an accident of the aircraft. The contents of this type of memory can also be recovered after dismantling the memory of its support. Advantageously, the memory 29 is a programmable fast memory called FPROM, acronym for the English expression "Flash Programmable Read OnIy Memory", also more simply called "flash memory". The flash memory allows the modification of several memory spaces in a single operation and is therefore characterized by very high read and write speeds. It is of reduced dimensions, which reduces the risk of damage in an accident of the aircraft.

In a particular embodiment, the memory 29 is a flash memory with NOR logic, better known under the Anglo-Saxon expression "NOR". This type of memory has an addressing interface allowing random and fast access to any location in the memory. It is therefore particularly suitable for storing computer programs, which can be executed directly from the memory.

FIG. 4 illustrates the contents of a part of a memory 29 of the standby instrument 4 according to the invention. The standby instrument 4 may include means for steadily recording the flight information and means for managing the recording of the spare flight information in the form of a turntable. The contents of the memory 29 are divided into two zones, a first zone being dedicated in particular to the storage of the initialization parameters and computer programs, and a second emergency zone 40 being reserved for storing the emergency flight information. As indicated previously, the two zones can correspond to two distinct physical memories. The content of the emergency zone 40 is structured as a turntable. In this turntable, a first line 41 contains all the emergency flight information taken at a time t ₀ . The following line 42 contains the same emergency flight information taken at a following instant (t _o + τ), where τ represents the time interval elapsed between the two recordings of the rescue flight information. In a particular embodiment, τ is a time constant. The following record therefore occurs at a time (t ₀ + 2.τ). In general, the emergency flight information is recorded at times (t _o + i.τ), i being an integer between 0 and n, ("+ 1) being the maximum number of lines available for recording the information of rescue flight. At the instant (t ₀ + (n + i) .τ), the emergency flight information is again recorded in the first line 41, and so on. This turntable principle allows sequential recording of the emergency flight information and keeping in memory the last flight hours emergency flight information. The memory 29 may for example be sized so as to be able to keep the last or the last 25 hours of flight with an interval τ of a few seconds or a few minutes. The interval τ may for example be one second. According to a particular embodiment, each emergency flight information, namely the altitude, the speed, the roll, the pitch and the yaw of the aircraft, is recorded in a column 43, 44, 45, 46, 47. , 48, 49. Thus, each spare flight information at a given instant is stored in a specific memory location, the memory location may occupy one or more physical elements of the memory 29 depending on the size of the information. According to another embodiment, the emergency zone 40 of the memory 29 can record, with the emergency flight information, the emergency signals from the sensors 20, 21, 24 or only these emergency signals. The standby instrument 4 may be connected to the means for calculating and displaying the primary flight information and comprise means for recording in normal operation the primary flight information and / or the primary signals in the memory 29 of the standby instrument. 4. In particular, the spare area 40 of the memory 29 may record the primary flight information and / or the primary signals from the primary systems 27, such as a temperature, an air speed, or an ascent rate. The Mach number, an important parameter in the determination of the lift, can also be stored in the memory 29. Advantageously, all the recorded information is distributed in the emergency zone 40 of the memory 29 in the form of columns 43, 44, 45, 46, 47, 48, 49, each column containing a type of information.

The rescue instrument 4 according to the invention makes it possible to have the emergency flight information even in the event of failure of the primary systems 27 or the flight recorders during the flight of the aircraft. The rescue flight information also remains available in the event of complete destruction of the flight recorders in an accident.

The rescue instrument 4 according to the invention also makes it possible to record flight information and navigation information from the primary systems. In addition, it has the advantage of not requiring additional memory, but only a modification of the computer program of the standby instrument 4. The standby instrument 4 according to the invention is therefore of economical design and facilitates determining the circumstances and causes of an aircraft accident.

Claims

1. Emergency instrument capable of equipping a dashboard (1) of an aircraft, the emergency instrument (4) comprising means (11, 25, 28) for calculating and displaying emergency flight information from emergency signals provided by emergency equipment (20, 21, 22, 23, 24) of the aircraft, the display of the emergency flight information for the piloting of the aircraft, characterized in that it comprises a memory (29) and means (30) for recording in normal operation the emergency flight information and / or the spare signals in the memory (29) of the standby instrument (4), the recorded data allowing the re-display flight information displayed during the recording.

2. Emergency instrument according to claim 1, characterized in that the re-display is on the means (1 1, 25, 28) for calculating and displaying emergency flight information.

3. Emergency instrument according to one of claims 1 or 2, characterized in that the dashboard (1) comprises means (2, 3) for calculating and displaying primary flight information from primary signals provided by primary equipment of the aircraft, in that the standby instrument (4) is connected to the means (2, 3) for calculating and displaying the primary flight information and in that it comprises means (29, 30 ) to record in normal operation the primary flight information and / or the primary signals in the memory (29) of the standby instrument (4).

4. Emergency instrument according to one of the preceding claims, characterized in that it comprises means (29, 30) for recording at regular intervals (τ) the flight information and / or signals.

5. Emergency instrument according to claim 4, characterized in that the interval (τ) is one second.

6. Emergency instrument according to one of the preceding claims, characterized in that it comprises means (29, 30) for managing the recording of flight information and / or signals in the form of turntable (40).

7. Emergency instrument according to one of the preceding claims, characterized in that the memory (29) of the standby instrument (4) is a FPROM type memory.

8. Emergency instrument according to one of the preceding claims, characterized in that the emergency flight information comprises an altitude, a speed and an attitude of the aircraft.