AIRCRAFT EMERGENCY OXYGEN SUPPLY DEVICE, AIRCRAFT COMPRISING SUCH AN EMERGENCY OXYGEN SUPPLY DEVICE, AND METHOD OF OPERATING AN AIRCRAFT EMERGENCY OXYGEN SUPPLY DEVICE

Abstract

An aircraft emergency oxygen supply device comprises an oxygen source for supplying oxygen gas; a backup electric power supply system, comprising at least one electric power storage device; and a controller for controlling the operation of the aircraft emergency oxygen supply device. The aircraft emergency oxygen supply device is electrically connectable to an aircraft electric power supply system for being supplied with electric power provided by the aircraft electric power supply system; the at least one electric power storage device is chargeable by electric power provided by the aircraft electric power supply system; and the aircraft emergency oxygen supply device is operational with electric power provided by the backup electric power supply system.

Claims

1. An aircraft emergency oxygen supply device, comprising: an oxygen source for supplying oxygen gas; a backup electric power supply system, comprising at least one electric power storage device; and a controller for controlling the operation of the aircraft emergency oxygen supply device; wherein the aircraft emergency oxygen supply device is electrically connectable to an aircraft electric power supply system for being supplied with electric power provided by the aircraft electric power supply system; wherein the at least one electric power storage device is chargeable by electric power provided by the aircraft electric power supply system; and wherein the aircraft emergency oxygen supply device is operational with electric power provided by the backup electric power supply system.

2. The aircraft emergency oxygen supply device according to claim 1, wherein the aircraft emergency oxygen supply device is operational with electric DC power having a voltage in the range of between 15 V and 35 V, in particular a voltage in the range of between 20 and 30 V, more in particular having a voltage in the range of between 27.5 and 28.5 V.

3. The aircraft emergency oxygen supply device according to claim 1, wherein the aircraft emergency oxygen supply device has a power supply input terminal for receiving electric power from the aircraft electric power supply system; and wherein the aircraft emergency oxygen supply device has at least one activation input terminal for receiving an activation signal activating the aircraft emergency oxygen supply device; wherein the activation input terminal is in particular provided separately and independently from the power supply input terminal.

4. The aircraft emergency oxygen supply device according to claim 3, wherein the activation input terminal is configured for receiving the activation signal via a wired connection and/or via a wireless connection.

5. The aircraft emergency oxygen supply device according to claim 1, further comprising an electric charge sensor for determining a current charging state of the at least one electric power storage device, wherein the aircraft emergency oxygen supply device comprises in particular a charge indicator device for indicating the current charging state of the at least one electric power storage device.

6. The aircraft emergency oxygen supply device according to claim 5, wherein the backup electric power supply system is configured for issuing a status signal, in particular an electric, visual and/or acoustic status signal, indicative of the current charging state of the at least one electric power storage device, and/or wherein the backup electric power supply system is configured for issuing an alarm signal, in particular an electric, visual and/or acoustic alarm signal, in case the current charging state of the at least one electric power storage device is below a predefined threshold.

7. The aircraft emergency oxygen supply device according to claim 1, wherein the oxygen source comprises a chemical oxygen generator with a mechanical activator, wherein the mechanical activator is configured for starting a chemical reaction within the chemical oxygen generator after it has been mechanically triggered, wherein the at least one electric power storage device in particular has an electric storage capacity sufficient to effect deployment of at least one oxygen mask; or wherein the oxygen source comprises a chemical oxygen generator with an electric activator, in particular a pyroelectric actuator, wherein the electric activator is configured for starting a chemical reaction within the chemical oxygen generator after it has been electrically triggered, wherein the at least one electric power storage device in particular has an electric storage capacity sufficient to effect deployment of at least one oxygen mask and to operate the electric activator; or wherein the oxygen source comprises an oxygen gas storage device, in particular an oxygen gas bottle, in which a predefined amount of oxygen gas is stored; an electric activator, in particular a pyroelectric activator, for starting the supply of oxygen gas from the oxygen gas storage device; and a gas supply controller for controlling the supply of oxygen gas from the oxygen storage device to at least one oxygen mask; wherein the at least one electric power storage device in particular has an electric storage capacity sufficient to effect deployment of the at least one oxygen mask, to operate the electric activator, and to operate the gas supply controller.

8. The aircraft emergency oxygen supply device according to claim 1, further comprising at least one activation sensor, in particular at least one air pressure sensor, for providing an activation signal activating the aircraft emergency oxygen supply device, wherein the at least one activation sensor in particular is coupled to and/or arranged within the controller.

9. The passenger service unit, comprising an aircraft emergency oxygen supply device according to claim 1 and at least one of a reading light, a gasper, a loudspeaker, a switchable visual sign and an electric switch for switching the at least one reading light and/or for triggering a signal for calling cabin service personnel.

10. The aircraft, in particular an airplane or a helicopter, comprising: an aircraft electric power supply system; and at least one aircraft emergency oxygen supply device according to claim 1, which is coupled to the aircraft electric power supply system.

11. The aircraft according to claim 10, further comprising at least one activation switch, in particular a manual activation switch, which is coupled to the aircraft emergency oxygen supply device for selectively providing an activation signal to the aircraft emergency oxygen supply device.

12. The method of operating an aircraft emergency oxygen supply device according to claim 1, which is installed in an aircraft comprising an aircraft electric power supply system, wherein the method includes: charging the at least one electric power storage device of the backup electric power supply system with power supplied from the aircraft electric power supply system; and during flight of the aircraft, holding power for the operation of the aircraft emergency oxygen supply device available in the at least one electric power storage device.

13. The method according to claim 12, wherein the method further includes: in an emergency situation, operating the aircraft emergency oxygen supply device with electric power supplied by the aircraft electric power supply system, in case sufficient electric power is supplied by the aircraft electric power supply system; and in an emergency situation, operating the aircraft emergency oxygen supply device using electric power supplied by the backup electric power supply system, in case sufficient electric power is not supplied by the aircraft electric power supply system.

14. The method according to claim 12, wherein the method includes receiving an activation signal and activating the aircraft emergency oxygen supply device upon receipt of said activation signal; and/or wherein the method includes checking the current charging state of the at least one electric power storage device and providing a status signal, indicative of the current charging state, to the aircraft crew and/or to an aircraft control system.

15. The method according to claim 12, wherein said charging of the at least one electric power storage device of the backup electric power supply system with power supplied from the aircraft electric power supply system takes place when the aircraft is on the ground.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Further exemplary embodiments of the invention are described below with respect to the accompanying drawings, wherein:

[0066] FIG. 1 shows a schematic side view of an aircraft, in particular an airplane, in accordance with an exemplary embodiment of the invention;

[0067] FIG. 2 shows a perspective view of an aircraft emergency oxygen supply device in accordance with an exemplary embodiment of the invention, with the oxygen masks of the aircraft passenger oxygen supply module being shown in a deployed state;

[0068] FIG. 3 shows a schematic view of an overhead passenger service unit (PSU) housing an aircraft emergency oxygen supply device in accordance with an exemplary embodiment of the invention;

[0069] FIG. 4 shows a schematic block diagram of an aircraft emergency oxygen supply device in accordance with an exemplary embodiment of the invention.

DETAILED DESCRIPTION

[0070] FIG. 1 shows an aircraft 100, in particular an airplane, in accordance with an exemplary embodiment of the invention in a schematic side view. In the exemplary embodiment shown in FIG. 1, the aircraft 100 is a large passenger airplane, comprising a cockpit 103 and a passenger cabin 104, housing a plurality of passenger seats 106. In general, the aircraft may be a commercial passenger airplane, a private airplane, a military aircraft, or a rotorcraft, such as a helicopter.

[0071] The aircraft 100 comprises an aircraft electric power supply system 34, an aircraft control system 105, which may include one or more board computers, and a plurality of aircraft emergency oxygen supply devices 2. While the aircraft electric power supply system 34 is shown as a box for ease of representation, it is under-stood that the aircraft electric power supply system 34 can have any suitable form and extension. In particular, the aircraft electric power supply system 34 may be a distributed power supply system that provides electric power to a wide range of electric consumers across the aircraft 100.

[0072] In an exemplary configuration, in which the aircraft 100 comprises six passenger seats 106 in every row, each row of passenger seats 106 may have two aircraft emergency oxygen supply devices 2 associated therewith, one aircraft emergency oxygen supply device 2 assigned to the passenger seats 106 on the left side of a center aisle and one aircraft emergency oxygen supply device 2 assigned to the passenger seats 106 on the right side of the center aisle.

[0073] For the exemplary embodiment of each row of passenger seats 106 having six seats, every aircraft emergency oxygen supply device 2 may include one oxygen source 20 and three oxygen masks 12, coupled to the oxygen source 20. Such a set-up is schematically illustrated in FIG. 1 via three exemplary passenger windows 102, each being associated with a row of passenger seats 106, and via three exemplary aircraft emergency oxygen supply devices 2, depicted in phantom due to their arrangement within the aircraft 100.

[0074] FIG. 2 depicts an aircraft emergency oxygen supply device 2 in accordance with an exemplary embodiment of the invention, as it may be installed in the passenger cabin 104 of an aircraft 100. The aircraft emergency oxygen supply device 2 depicted in FIG. 2 comprises an oxygen source 20 and three oxygen masks 12. Each oxygen mask 12 is fluidly coupled with the oxygen source 20 by an oxygen hose 14, allowing the oxygen source 20 to supply oxygen gas via the oxygen hose 14 to the respective oxygen mask 12. A mechanical link 15, such as a wire or a cord, extends between an activator 18 of the oxygen source 20 and every oxygen mask 12, respectively.

[0075] During normal operation of the aircraft 100, the oxygen masks 12 are stored within a compartment 22, and a movable door 24 of the aircraft emergency oxygen supply device 2 is in a closed position, in which it covers the oxygen source 20 and prevents the oxygen masks 12 from dropping out of the compartment 22.

[0076] In case of pressure loss within the passenger cabin 104, the movable door 24 opens, allowing the oxygen masks 12 to drop out of the compartment 22, so that passengers sitting below the compartment 22 may grab the oxygen masks 12. When at least one of the oxygen masks 12 is grabbed and pulled towards a passenger, the activator 18 is triggered via the mechanical link 15, also referred to as lanyard 15, extending between the respective oxygen mask 12 and the activator 18. After being triggered, the activator 18 provides a trigger input to the oxygen source 20, initiating the provision of oxygen gas by the oxygen source 20.

[0077] In exemplary embodiments of the invention, the aircraft emergency oxygen supply device 2 may have a wide range of different types of oxygen sources 20. The oxygen source may be a stand-alone unit that is able to provide oxygen by itself, i.e. without receiving oxygen from an entity outside of the aircraft emergency oxygen supply device. The oxygen source may be a pressurized oxygen container, such as a pressurized oxygen cylinder. It is also possible that the oxygen source is a chemical oxygen generator. The chemical oxygen generator may generate oxygen at the time of use via a chemical reaction. The pressurized oxygen container may have a mechanical activator/actuator/initiator or a pyroelectric activator/actuator/initiator. Similarly, the chemical oxygen generator may have a mechanical starter or a pyroelectric starter. In the following paragraphs, three different types of oxygen sources are discussed in more detail.

[0078] The oxygen source 20 may be a chemical oxygen generator 20 with a mechanical activator 18. In such a configuration, the activator 18, after being mechanically triggered via the mechanical link 15, starts a chemical reaction within the chemical oxygen generator 20. The chemical reaction produces oxygen, which is supplied to the oxygen masks 12 via the oxygen hoses 14. In an aircraft emergency oxygen supply device 2 comprising a chemical oxygen generator 20 with a mechanical activator 18, electric power is needed only for deploying the oxygen masks 12, e.g. by unlocking and/or opening the movable door 24 when the aircraft emergency oxygen supply device 2 is activated, but no electric energy is needed for starting and operating the oxygen generator 20.

[0079] In another embodiment, the oxygen source 20 is a chemical oxygen generator 20 which is equipped with an electric activator 18. In this case, the electric activator 18 may be activated by closing an electric switch for applying an electric voltage to the electric activator 18. The electric switch may be activated via a mechanical link 15, such as the lanyard 15, as it is depicted in FIG. 4. The electric switch may also be activated via an electric signal, such as a sensor signal or an activation command signal. After being electrically activated, the electric activator 18 activates a chemical reaction within the chemical oxygen generator 20. The chemical reaction pro-duces oxygen, which is supplied to the oxygen masks 12 via the oxygen hoses 14. In an aircraft emergency oxygen supply device 2 comprising a chemical oxygen generator 20 with an electric activator 18, electric power is needed for deploying the oxygen masks 12 by unlocking and/or opening the movable door 24 and for operating the electric activator 18. No electric energy is needed for continuing the operation of the oxygen generator 20 after it has been started.

[0080] In yet another embodiment, the oxygen source 20 comprises an oxygen gas storage device, for example an oxygen gas bottle. A defined amount of a gas comprising a predefined percentage of oxygen is stored within the oxygen gas storage device. The oxygen source 20 further comprises an electric activator 18, in particular a pyroelectric activator 18, for starting the supply of oxygen gas from the oxygen gas storage device. The oxygen source 20 may also comprise a gas supply controller, which is configured for controlling the supply of the gas comprising oxygen from the oxygen storage device to the oxygen masks 12.

[0081] In such an embodiment, electric power is needed for deploying the oxygen masks 12 by unlocking and/or opening the movable door 24, for operating the (pyro) electric activator 18, and for continuously operating the gas supply controller over the full operation time of the aircraft emergency oxygen supply device 2 after the oxygen source 20 has been activated.

[0082] FIG. 3 depicts a schematic view of an overhead passenger service unit (“PSU”) 108, which may be arranged above the passenger seats 106 of a single passenger row. The overhead passenger service unit 108 may house an aircraft emergency oxygen supply device 2 in accordance with an exemplary embodiment of the invention.

[0083] FIG. 3 depicts the passenger service unit 108 as it is seen from the side of a passenger sitting on a passenger seat 106 below the overhead passenger service unit 108.

[0084] On the side, which is shown to the left in FIG. 3, the overhead passenger service unit 108 comprises a row of three adjustable reading lights 126a-126c, which are arranged next to each other.

[0085] Six electrical switches 127a-127c, 128a-128c are provided to the right side of the reading lights 126a-126c, a respective pair of two switches 127a-127c, 128a-128c next to each of the reading lights 126a-126c. A first one of the switches 127a-127c of each pair is configured for switching the adjacent reading light 126a-126c, and the second switch 128a-128c of each pair is configured for triggering a signal for calling cabin service personnel.

[0086] A row of three adjacent gaspers 129a-129c is provided next to the switches 127a-127c, 128a-128c.

[0087] Adjacent to the gaspers 129a-129c is a movable door 24, which covers a compartment 22, which is not visible in FIG. 3, housing at least three oxygen masks 12 (not shown), similar to the configuration depicted in FIG. 2.

[0088] In the event of pressure loss within the passenger cabin 104, the movable door 24 will open, allowing the oxygen masks 12 to drop out of the compartment 22, and each of the passengers sitting below the overhead passenger service unit 108 may grasp one of the oxygen masks 12. After being activated, an oxygen source 20 will supply the oxygen masks 12 with oxygen, as it has been described before with reference to FIG. 2.

[0089] On the side opposite to the gaspers 129a-129c, a grid 142 is formed within over-head passenger service unit 108. A loudspeaker (not shown), which may be used for delivering acoustic announcements to the passengers, may be arranged behind said grid 142.

[0090] Next to the grid 142, there is a display panel 144, which may be configured for selectively showing a plurality of visual signs (not shown), such as “non smoking” or “fasten your seat belt”. The display panel 144 may be illuminated from behind, in order to deliver visual information to the passengers sitting below the overhead passenger service unit 108.

[0091] The passenger service unit 108 may be coupled to the aircraft electric power supply system as a whole, with the distribution of electric power among above de-scribed components taking place within the passenger service unit 108. It is also possible that individual ones or all of above described components of the passenger service unit 108 are coupled to the aircraft electric power supply system separately.

[0092] FIG. 4 shows a schematic block diagram of an aircraft emergency oxygen supply device 2 in accordance with an exemplary embodiment of the invention.

[0093] For simplicity of the illustration, FIG. 4 shows only a single oxygen mask 12, which is fluidly coupled to an oxygen source 20 by means of an oxygen hose 14, as depicted in FIG. 2. A mechanical link 15, which may be a wire or a cord, ex-tends between the oxygen mask 12 and the activator 18, which is provided at the oxygen source 20.

[0094] The skilled person understands that an aircraft emergency oxygen supply device 2, as it is depicted in FIG. 4, may comprise more than one oxygen mask 12. A plurality of oxygen masks 12 may be fluidly coupled to a common oxygen source 20. Alternatively, the aircraft emergency oxygen supply device 2 may comprise a plurality of oxygen sources 20. In particular, the aircraft emergency oxygen supply device 2 may comprise a separate oxygen source 20 for each oxygen mask 12.

[0095] The aircraft emergency oxygen supply device 2 further comprises a controller 26, which is configured for controlling the operation of the aircraft emergency oxygen supply device 2. The controller 26 is in particular configured for controlling an actuator 30, which is provided for unlocking and/or opening the movable door 24 of the aircraft emergency oxygen supply device 2, in order to provide passengers with access to the at least one oxygen mask 12 of the aircraft emergency oxygen supply device 2, as it is depicted in FIG. 2.

[0096] If the oxygen source 20 comprises an electric activator 18, i.e. an activator which is electrically operated, as it has been described before, the controller may be further configured for controlling, in particular for triggering, the electric activator 18.

[0097] In a configuration in which the oxygen source 20 comprises a gas storage device, such as a gas bottle, the controller 26 may further provide the functionality of a gas supply controller 25 for controlling the supply of the gas comprising oxygen from the oxygen storage device to the oxygen masks 12. Alternatively, the gas supply controller may be provided separately from the controller 26. In such a configuration the gas supply controller is coupled with the controller 26 for being triggered and/or controlled by the controller 26.

[0098] The aircraft emergency oxygen supply device 2 comprises a power input terminal 36, and at least one activation input terminal 38. The power input terminal 36 and the at least one activation input terminal 38 are electrically coupled with the controller 26.

[0099] When the aircraft emergency oxygen supply device 2 is installed within an aircraft 100, electric power supply lines 32 are electrically coupled with the power input terminal 36 for supplying electric power from the aircraft electric power supply system 34 to the aircraft emergency oxygen supply device 2. The aircraft electric power supply system 34 may be configured for supplying electric DC power, having a voltage in the range of between 15 V and 35 V, in particular a voltage in the range of between 20 and 30 V, more particularly having a voltage in the range of between 27.5 and 28.5 V.

[0100] The aircraft emergency oxygen supply device 2, in particular the controller 26 thereof, is configured for receiving an activation signal for activating the aircraft emergency oxygen supply device 2.

[0101] In an exemplary embodiment, the aircraft emergency oxygen supply device 2 may comprise an air pressure sensor 41. The air pressure sensor 41 may be configured for detecting the pressure of air within a passenger cabin 104 and for supplying an activation signal in case the pressure of air detected by the air pressure sensor 41 is below a predefined threshold. A configuration comprising a pressure sensor 41 may allow for automatically activating the aircraft emergency oxygen supply device 2, in case the pressure of air within the passenger cabin 104 drops below a predefined threshold causing an emergency situation.

[0102] Additionally or alternatively, an air pressure sensor 41 may be provided outside and/or separately from the aircraft emergency oxygen supply device 2. In such a configuration, the air pressure sensor 41 may be coupled to the controller 26 via the at least one activation input terminal 38.

[0103] Additionally or alternatively, a manual activation switch 42 may be electrically coupled to the at least one activation input terminal 38, in order to allow for activating the aircraft emergency oxygen supply device 2 by operating the manual activation switch 42. A manual activation switch 42 may be located within the passenger cab-in 104 for being operated by members of the passenger cabin crew. Alternatively or additionally, a manual activation switch 42 may be provided within the cockpit 103 of the aircraft 100 for being operated by the pilot(s).

[0104] As a further option, a seat occupancy sensor 43 may be coupled to the at least one activation input terminal 38. In a configuration including a seat occupancy sensor 43, the controller 26 may be configured for activating the aircraft emergency oxygen supply device 2 only if at least one passenger seat 106, which is associated with the aircraft emergency oxygen supply device 2, is occupied by a passenger.

[0105] The pressure sensor 41, the at least one manual activation switch 42, and/or the seat occupancy sensor 43 may by coupled to the at least one activation input terminal 38 by electric signal lines providing a wired connection 39 for transmitting the activation signal.

[0106] Alternatively or additionally to a wired connection, the pressure sensor 41, the at least one manual activation switch 42, and/or the seat occupancy sensor 43 may by coupled to the at least one activation input terminal 38 by means of a wireless connection, for example by a wireless connection, which is implemented using WLAN, Bluetooth®, infrared data transmission, or a similar technology which is suit-able for wireless data transmission.

[0107] The aircraft emergency oxygen supply device 2 further comprises a backup electric power supply system 28. The backup electric power supply system 28 includes at least one electric power storage device 29. The electric power storage device 29 is a rechargeable electric power storage device, for example an electric recharge-able battery or a capacitor or a supercapacitor or another suitable rechargeable electric power storage device. The backup electric power supply system 28 is con-figured for supplying electric power for operating the aircraft emergency oxygen supply device 2 in emergency situations, in which no or not enough electric power for operating the aircraft emergency oxygen supply device 2 is supplied by the air-craft electric power supply system 34. In consequence, the backup electric power supply system 28 allows the aircraft emergency oxygen supply device 2 to operate reliably, even in case of a malfunction or a breakdown of the aircraft electric power supply system 34.

[0108] The electric capacity of the backup electric power supply system 28, in particular the electric capacity of the at least one electric power storage device 29, depends on the amount of electric energy which is needed for reliably operating the aircraft emergency oxygen supply device 2 in case of a malfunction or a breakdown of the aircraft electric power supply system 34.

[0109] As it has been described before, electric power is always needed for unlocking and/or opening the movable door 24 of the compartment 22. Thus, the backup electric power supply system 28 is configured such that it is capable to provide sufficient electric power for deploying the oxygen masks 12 by unlocking and/or opening the movable door 24 of the compartment 22.

[0110] In case the aircraft emergency oxygen supply device 2 is equipped with a (pyro) electric activator for starting the production and/or the supply of oxygen comprising gas, the backup electric power supply system 28 is configured such that it is additionally capable to provide sufficient electric power for reliably operating the electric activator in order to reliably start the production and/or the supply of oxygen comprising gas, which is to be delivered to the oxygen masks 12.

[0111] In case the aircraft emergency oxygen supply device 2 further comprises a gas supply controller 25 for controlling the supply of gas to the oxygen masks 12, the backup electric power supply system 28 is configured such that it is additionally capable to provide sufficient electric power for reliably operating the gas supply controller 25.

[0112] In this case, the backup electric power supply system 28 is configured such that it is capable to provide sufficient electric power for reliably operating the aircraft emergency oxygen supply device 2 not only over the relatively short starting phase in which the oxygen source 20 is activated, but over its full operating time, i.e. over the whole period of time in which the oxygen source 20 is supplying oxygen gas to the oxygen masks 12.

[0113] Thus, the electric capacity of the backup electric power supply system 28, which is defined by the electric capacity of the at least one electric power storage device 29, may be larger if the electric energy stored within the at least one electric power storage device 29 is needed not only for deploying the oxygen masks 12, but also for operating an electric activator 17. The electric capacity of the backup electric power supply system 28 may be even larger if additional electric energy is needed for operating a gas supply controller 25 of the aircraft emergency oxygen supply device 2, which controls the supply of oxygen gas to the oxygen masks 12.

[0114] The at least one electric power storage device 29 of the backup electric power supply system 28 is directly chargeable with electric power provided by the aircraft electric power supply system 34. In particular, in an aircraft emergency oxygen supply device 2 according to an exemplary embodiment of the invention, no energy harvesting device, which is configured for transferring optical or mechanical energy into electric power, is employed for providing the electric power used for charging the at least one electric power storage device 29.

[0115] Thus, in situations in which the aircraft electric power supply system 34 is properly operating, so that it supplies sufficient electric power to the aircraft emergency oxygen supply device 2, the controller 26 and/or the backup electric power supply system 28 may supply electric power, which is supplied from the aircraft electric power supply system 34 via the electric power supply lines 32, to the at least one electric power storage device 29 for charging the at least one electric power storage device 29.

[0116] The at least one electric power storage device 29 may for example be charged every time the aircraft electric power supply system 34 is activated, in particular every time before the aircraft 100 takes off.

[0117] The at least one electric power storage device 29 may also be charged during the flight, as long as the aircraft electric power supply system 34 is working properly. The at least one electric power storage device 29 may in particular be charged sufficiently for maintaining a fully charged state of the at least one electric power storage device 29 over the complete flight.

[0118] In an embodiment, the aircraft emergency oxygen supply device 2 further comprises an electric charge sensor 27. The electric charge sensor 27 is electrically coupled with the at least one electric power storage device 29 for determining a current charging state of the at least one electric power storage device 29.

[0119] The aircraft emergency oxygen supply device 2 may also comprise at least one charge indicator device 31, which is configured for indicating the current charging state of the at least one electric power storage device 29.

[0120] The at least one charge indicator device 31 may, for example, be an optical charge indicator device 31, which provides an optical signal indicating the current charging state of at least one electric power storage device 29, electrically coupled with the charge indicator device 31. For indicating the current charging state of at least one electric power storage device 29, the optical charge indicator device 31 may, for example, include a plurality of LEDs of different colors, which are activated and deactivated depending on the current charging state of the at least one electric power storage device 29.

[0121] Alternatively, the optical charge indicator device 31 may comprise a single LED, which is configured for emitting light of different colors as a function of the current charging state of the at least one electric power storage device 29.

[0122] Other types of optical charge indicator devices 31 may be employed as well. Charge indicator devices 31, provided at the aircraft emergency oxygen supply devices 2, may allow members of the cabin crew to conveniently and reliably check the current charging states of the electric power storage devices 29 of all aircraft emergency oxygen supply devices 2. The charging states may in particular be checked, before the aircraft 100 takes off. The take-off of the aircraft 100 may be delayed, until the charging states of the electric power storage devices 29 of all air-craft emergency oxygen supply devices 2 have reached a predefined minimum threshold.

[0123] Charge indicator devices 31 may further allow for detecting and reporting an unusual fast discharging of an electric power storage device 29, which may indicate a low capacity and/or a malfunction of an electric power storage device 29. Detecting a low capacity and/or a malfunction of an electric power storage device 29 may result in a replacement of said electric power storage device 29.

[0124] The backup electric power supply system 28 may also be configured for providing a status signal at a status signal output terminal 40 of the aircraft emergency oxygen supply device 2. The status signal, which is indicative of the current charging state of the at least one electric power storage device 29, may be an electric, a visual and/or an acoustic status signal. An electric status signal may be forwarded to the aircraft control system 105, which may include a data logging system for logging operational parameters of the aircraft 100.

[0125] The backup electric power supply system 28 and/or the aircraft control system 105 may in particular be configured for issuing an alarm signal, in particular an electric, visual and/or acoustic alarm signal, in case the detected charging state of the at least one electric power storage device 29 is below a predefined threshold. The air-craft control system 105 may in particular be configured such that the detection of an alarm signal prevents the aircraft 100 from taking-off, until all electric power storage devices 29 of the aircraft 100 have been charged sufficiently, so that the charging state of the at least one electric power storage device 29 exceeds the predefined threshold.

[0126] The aircraft 100 may be configured such that it is allowed to take off only if at least the electric power storage devices 29 of all aircraft emergency oxygen supply devices 2, which are assigned to occupied seats, are sufficiently charged.

[0127] The pilots may be able to manually override an alarm signal and to take off with the aircraft 100, although not all electric power storage devices 29 are sufficiently charged, in order to allow the aircraft 100 to take off under special circumstances, in which it is necessary or desirable to take off although not all of the electric power storage devices 29 are sufficiently charged.

[0128] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.