Methods and systems for decontaminating aircraft cabins and providing indications for safe reentry

Described herein are methods and systems for decontaminating aircraft cabins and providing an indication to provide confidence that the cabins are safe for reentry post-operation. These methods and systems are based on reducing concentrations of infectious agents inside a cabin utilizing outside air and/or filtered air. In some examples, a method is performed after a certain contamination event (e.g., a sick person present on a flight and/or as a part of periodic service (e.g., in between flights. The amount of time the system is run to introduce compounds into the cabin is specifically calculated to lower the fraction of the remaining infectious agents below a certain desired level, thereby reducing the contamination concentration in the cabin from the initial concentration. The decontamination duration depends on the cabin volume and the incoming airflow rates. For example, the fraction of the remaining is brought below 5% after 9 minutes of flowing incoming air at 20 air changes per hour.

BACKGROUND

Contaminants may be introduced or appear in various areas of an aircraft and other types of vehicles causing the areas to become unsuitable for further use. For example, with the growing popularity of air and other forms of travel and new destinations, the potential for transmission of infectious diseases has dramatically increased. Conventional decontamination processes can take significant amounts of time and may leave certain areas unattended.

SUMMARY

Described herein are methods and systems for decontaminating aircraft cabins and providing indications that the cabins are safe for reentry. These methods and systems are based on replacing the air inside aircraft cabins with outside air and/or filtered air. In some examples, a method is performed after a certain contamination event (e.g., a sick person is present on a flight) and/or as a part of periodic service (e.g., in between flights). The amount of air introduced into the cabin is specifically calculated to reduce the fraction of the remaining air below a certain desired level, thereby reducing the contamination concentration in the cabin. The decontamination duration depends on the cabin volume and the incoming airflow rates.

For example, the fraction of the remaining air is brought below 5% after 10 minutes at a flow rate of 20 air changes per hour.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented concepts. In some examples, the presented concepts are practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail to not unnecessarily obscure the described concepts. While some concepts will be described in conjunction with the specific examples, it will be understood that these examples are not intended to be limiting.

Introduction

Described herein are systems and methods for decontaminating aircraft cabins and for external identification of the decontamination process completion (e.g., when the aircraft cabins are substantially free from infectious agents/diseases and are ready for reentry). In some examples, these systems and methods at least partially rely on existing environmental control systems (ECS) of aircraft, while providing new indication features to various users (e.g., airlines, flight crew, maintenance, ground crew).

For example, a decontamination system is activated when no people are present in the aircraft cabin and, in some examples, when the doors to the aircraft system are closed. A controller determines a required output of one or more air conditioning packs and/or of one or more fans to deliver air into the cabin, defining the total incoming flow rate. In some examples, this total incoming flow rate is presented in terms of air changes per hour, with 1 air change per hour representing a flow rate corresponding to a volume of the aircraft divided by an hour. It should be noted that when an incoming air is flown into the cabin, this incoming air displaces corresponding amounts of air, which is referred to as displaced air. Initially, the displaced air is primarily the air, which was present in the cabin before the system activation and which is referred to as original air. As the decontamination proceeds forward, the original air represents a smaller fraction of the displaced air since the ratio of the original air (to the total air) in the cabin decreases. This fraction is referred to as a remaining air fraction. The decontamination process proceeds until reaching a certain minimal level of the remaining air fraction by replacing the original air in the cabin. This minimal level of the remaining air fraction is selected, e.g., based on the type of contaminants, the likelihood of contamination, and other like factors.

The total incoming flow rate, the volume of the aircraft, and the desired level of the remaining air fraction are used by the controller to determine the duration of the decontamination process. In some examples, additional inputs (e.g., from one or more biosensors positioned in the aircraft cabin) to the controller are used to determine the duration (e.g., extend the decontamination process if the contaminants are still present above the allowable level).

Upon completion of the decontamination process, the controller provides input to an external indicator (e.g., positioned outside the cabin) that the decontamination process is completed and that the cabin is ready to enter. It should be noted that, in some examples, entering the aircraft cabin during the decontamination process interferes with the decontamination process (e.g., alters the air circulation) and/or potentially unsafe to entering personnel (e.g., contaminants can be suspended in the air). In some examples, the external indicator is a light, positioned proximate to an aircraft door.

In some examples, the system is initiated and controlled manually. For example, a switch at a flight deck is used to start the decontamination process. In some examples, the system is initiated and controlled automatically. For example, a door sensor is used to initiate the process, e.g., upon detecting that all doors are closed. In some examples, a biosensor and/or other types of sensors are used to provide one or more inputs (e.g., the level of contaminants in the cabin) to the controller. Furthermore, in some examples, the biosensor checks the air of the newly cleaned/purged cabin to ensure that the timer and controller were effective in completely purging and cleaning the cabin air. In some examples, the controller is used to control the speed of the fans of the ECS system (e.g., ensuring a high flow rate through the cabin, thereby reducing the decontamination time). In some examples, variable-speed fans are used (instead of fixed-speed fans) to assist with the decontamination process and to achieve high flow rates.

Decontamination System Examples

FIG.1is a schematic illustration of aircraft190, comprising system100for decontaminating aircraft cabin150and providing an indication that aircraft cabin150is safe for reentry, in accordance with some examples.FIG.2is a block diagram of aircraft190inFIG.1, illustrating various components of the comprising system100.

Referring toFIGS.1and2, system100comprises one or more air conditioning packs130, configured to receive ambient air from outside aircraft190and to supply ambient air into cabin150of aircraft190. System100also comprises one or more filters142and one or more fans140, configured to receive cabin air from cabin150of aircraft190, to pass cabin air through one or more filters142thereby generating filtered air, and to supply filtered air into cabin150. In some examples, one or more air conditioning packs130, one or more fans140, and one or more filters142are parts of the ECS of aircraft190. In other words, one or more air conditioning packs130, one or more fans140, and one or more filters142are also used during other operations of aircraft190, such as during the flight. As such, in some examples, decontamination system100is at least in part or fully integrated into the ECS of aircraft190.

Referring toFIG.2, system100also comprises controller110, communicatively coupled to one or more air conditioning packs130and to one or more fans140. System100is configured to receive decontamination request122and to determine operating parameters112of one or more air conditioning packs130and one or more fans140to perform the decontamination of aircraft cabin150. Various types of operating parameters112are within the scope. For example, operating parameters112comprise the duration of operating one or more air conditioning packs130and one or more fans140. In some examples, the duration of operating one or more air conditioning packs130is the same as the duration of operating one or more fans140. Alternatively, the duration of operating one or more air conditioning packs130is different from the duration of operating one or more fans140. For example, the duration of operating one or more air conditioning packs130is longer than the duration of operating one or more fans140. In another example, the duration of operating one or more air conditioning packs130is shorter than the duration of operating one or more fans140. In some examples, the periods of operating one or more air conditioning packs130and operating one or more fans140coincide (e.g., start and finish at the same time). Alternatively, the periods of operating one or more air conditioning packs130and operating one or more fans140are staggered (e.g., start and/or finish at different time, but the operating periods overlap). For example, the process starts with operating one or more air conditioning packs130only, while one or more fans140are turned on lately. Alternatively, the process starts with operating one or more fans140only, while one or more air conditioning packs130are turned on lately.

In some examples, the duration of operating one or more air conditioning packs130and one or more fans140is determined based on one or more of (a) the cabin volume, (b) a combined ventilation rate provided by one or more air conditioning packs130and one or more fans140, and (c) an acceptable fraction of the remaining air in aircraft190. This determination is further described below with reference toFIGS.4and5. In general, a larger cabin volume requires longer decontamination and vice versa. A smaller combined ventilation rate requires longer decontamination and vice versa. A lower acceptable fraction of the remaining air requires longer decontamination and vice versa.

System100also comprises indicator128, communicatively coupled to controller110. Indicator128is configured to receive completion indication126from controller110and present completion indication126to people that aircraft190is safe for reentry. In some examples, completion indicator128is located outside of aircraft190and visible to the people outside aircraft190. For example, completion indicator123is located on one or more of a jet bridge, a jet bay, or an airport gate. In some examples, completion indicator128comprises or is coupled to a wireless transmitter, e.g., to inform remote users and systems about the completion of the decontamination process. For example, the departing time of a flight is conditioned on the completion of the decontamination process.

In some examples, system100further comprises input device120, communicatively coupled to controller110and configured to send decontamination request122to controller110. For example, input device120is one of a flight deck switch or an attendant panel. However, other examples within the scope.

In some examples, system100further comprises one or more biosensors152, positioned within cabin150of aircraft190. One or more biosensors152are configured to measure the presence or, more specifically, the concentration of one or more contaminants in cabin150. One or more biosensors152are communicatively coupled to controller110and configured to provide contamination concentration input153to controller110. In these examples, controller110is configured to use contamination concentration input153to trigger the operation of one or more air conditioning packs130and one or more fans140. For example, one or more biosensors152determined the concentration of a contaminant exceeding a certain threshold and informs controller110about the event. This part of the process is performed at any time. In some embodiments, one or more biosensors152continuously monitor contaminants in cabin150. Upon receiving contamination concentration input153from one or more biosensors152, controller110schedules a decontamination process, which may or may not occur immediately. For example, cabin150is still occupied when the contamination even was detected, in which case the decontamination process is scheduled for a future, e.g., when cabin150is free from occupants.

In some examples, controller110is configured to use contamination concentration input153to revise operating parameters112of one or more air conditioning packs130and one or more fans140. For example, the initially determined duration of operating one or more air conditioning packs130and one or more fans140is revised based on contamination concentration input153(e.g., shortened if contamination concentration input153indicates a faster decay of the contaminant concentration, or lengthened if contamination concentration input153indicates a slower decay of the contaminant concentration).

In some examples, operating parameters112further comprise the operating output of each of one or more air conditioning packs130and each of one or more fans140. It should be noted that a combined ventilation rate is based on the ventilation rate of one or more air conditioning packs130and the ventilation rate of each of one or more fans140. In some examples, the ratio of the ventilation rate of one or more air conditioning packs130to the ventilation rate of each of one or more fans140is 50%-to-50%. In some examples, this ratio is in the range of 10%-to-90% to 90%-to-10%. The ratio is selected, e.g., based on conditions of one or more filters142, outside weather conditions (e.g., temperature, humidity), and the like.

In some examples, system100further comprises one or more door sensors154, positioned at each cabin door. One or more door sensors154are configured to determine whether each cabin door is closed or open. It should be noted that the decontamination process has different efficiencies depending on the position of the cabin doors. Furthermore, closing the doors helps to control the spread of contaminants. In some examples, the decontamination process is initiated only when all doors are closed.

One or more door sensors154are communicatively coupled to controller110and configured to provide door closure input157to controller110. Controller110is configured to operate one or more air conditioning packs130and one or more fans140is initiated based on door closure input157. For example, controller110delays this operation until all cabin doors are closed. In some examples, the process proceeds when one or more doors remain open. In some examples, operating parameters112of one or more air conditioning packs130and one or more fans140are further determined based on door closure input157. For example, if one or more doors are open, then a higher combined ventilation rate is used.

FIG.3illustrates various inputs and outputs to controller110. For example, controller110receives (or stores) the cabin volume information, which is used for determining (e.g., calculating) operating parameters112, such as operating duration113. In the same or other examples, controller110receives (or stores) the combined ventilation rate, which is also used for determining operating parameters112, such as operating duration113. In the same or other examples, controller110receives (or stores) the remaining air threshold, which is also used for determining operating parameters112, such as operating duration113. Other examples of controller inputs include a decontamination request, a contaminant concentration, a door closure input. The controller used this information to determine operating parameters112, which are passed to one or more air conditioning packs130and one or more fans140during the execution of the decontamination process. Furthermore, controller110generates completion indicator126, which is passed to, e.g., indicator128.

Decontamination Method Examples

FIG.4is a process flowchart of method400for decontaminating aircraft cabin150and providing an indication that aircraft cabin150is safe for reentry, in accordance with some examples. Various operations of method400are performed using system100, which is described above with reference toFIGS.1-3.

Method400comprises receiving (block410) decontamination request122at controller110, For example, input device120sends decontamination request122to controller110, e.g., based on the identification of the contamination event in aircraft cabin150. Various examples of identifying the contamination event are within the scope, e.g., a passenger developing or reporting symptoms, receiving an external report based on a passenger manifest, receiving an input from one or more biosensors152, and the like. For example, decontamination request122is received from an input device120, communicatively coupled to controller110, wherein input device120is one of a flight deck switch or an attendant panel. In another example, decontamination request122is received from one or more biosensors152, positioned within cabin150of aircraft190. More specifically, decontamination request122comprises contaminant concentration input153, exceeding a set threshold.

Method400comprises determining (block420), at controller110, operating parameters112for one or more air conditioning packs130and for one or more fans140of aircraft190. Operating parameters112comprise at least the operating duration of one or more air conditioning packs130and of one or more fans140and, in some example, any operating staggering conditions. Other examples of operating parameters include operating output (e.g., a ventilation rate) of each of one or more air conditioning packs130and each of one or more fans140, sequence of operating one or more air conditioning packs130and one or more fans140, and the like. The duration of operating one or more air conditioning packs130and one or more fans140is determined based on at least (a) the cabin volume of aircraft190, (b) a combined ventilation rate provided by air conditioning packs130and one or more fans140, and (c) a remaining air threshold in aircraft190. The remaining air threshold reflects the concentration of the remaining contaminant in an aircraft cabin.

FIG.5illustrates plots of a remaining air fraction as a function of time for two different flow rates. Specifically, line500corresponds to a flow rate of 20 air changes per hour, while line510corresponds to a flow rate of 30 air changes per hour. Line520represents an example of a remaining air fraction threshold, set at 10% in this example. With a flow rate of 20 air changes per hour, the threshold is reached within about 7 minutes. With a flow rate of 30 air changes per hour, the threshold is reached within about 4 minutes. The threshold depends on the type of contaminants and other parameters.

Method400proceeds with operating (block430) one or more air conditioning packs130and one or more fans140in accordance with the operating parameters thereby decontaminating cabin150. In some examples, the operating output (e.g., a ventilation rate) of each one or more air conditioning packs130and each of one or more fans140varies while operating (block430) one or more air conditioning packs130and one or more fans140.

In some examples, the operation of one or more air conditioning packs130and one or more fans140is performed while aircraft190is grounded. Furthermore, in some examples, this operation is performed while aircraft190is empty and free of occupants (decision block426inFIG.4). For purposes of this disclosure, the term “occupant” is defined as a human or animal, capable of carrying a contaminant onboard aircraft190.

If the cabin is not empty, method400proceeds with vacating (block428) the occupants from aircraft cabin150. In some examples, method400further comprises confirming (block424) that cabin150of aircraft190is empty and free of occupants before performing operating (block430) one or more air conditioning packs130and one or more fans140.

Method400proceeds with providing (block440) completion indication126to indicator128upon completion decontaminating cabin150. For example, completion indicator128is located outside of aircraft190and visible to persons outside aircraft190. More specifically, completion indicator128is located on one or more of a jet bridge, a jet bay, or an airport gate. In some examples, completion indicator128comprises or is coupled to a wireless transmitter.

In some examples, method400further comprises receiving (block450) contaminant concentration153in cabin150. Contaminant concentration153is received at controller110and from one or more biosensors152positioned in a cabin150of aircraft190. Furthermore, contaminant concentration153is received while operating (block430) one or more air conditioning packs130and one or more fans140. For example, one or more biosensors152continuously monitor the concentration of the contaminants during the decontamination process, Method400continues with revising (block422) operating parameters112based on contaminant concentration153in cabin150.

In some examples, method400further comprises receiving (460), at controller110and from one or more door sensors154, door closure input157, corresponding to an open-close position of each cabin door. In more specific examples, the operation of one or more air conditioning packs130and one or more fans140(block430) is initiated or conditioned based on door closure input157(referring to decision block426inFIG.4). In some examples, operating parameters112of one or more air conditioning packs130and one or more fans140are further determined based on door closure input157.

Aircraft Examples

In some examples, methods and systems described above are used on aircraft and, more generally, by the aerospace industry. Specifically, these methods and systems can be used during the fabrication of aircraft as well as during aircraft service and maintenance.

Accordingly, the apparatus and methods described above are applicable for aircraft manufacturing and service method900as shown inFIG.6and for aircraft902as shown inFIG.7. During pre-production, method900includes specification and design904of aircraft902and material procurement906. During the aircraft production, component and subassembly manufacturing908and system integration910of aircraft902takes place. Thereafter, aircraft902goes through certification and delivery912to be placed in service914. While in service by a customer, aircraft902is scheduled for routine maintenance and service916, which also includes modification, reconfiguration, refurbishment, and so on.

In some examples, each of the processes of method900is performed or carried out by a system integrator, a third party, and/or an operator, e.g., a customer. For this description, a system integrator includes without limitation any number of aircraft manufacturers and major-system subcontractors; a third party includes without limitation any number of vendors, subcontractors, and suppliers; and an operator can be an airline, leasing company, military entity, service organization, and so on.

As shown inFIG.7, aircraft902produced by method900includes airframe918with plurality of systems920and interior922. The airframe918includes wings of the aircraft902. Examples of systems920include one or more propulsion system924, electrical system926, hydraulic system928, and environmental system930, Any number of other systems can be included.

Apparatus and methods presented herein can be employed during any one or more of the stages of method900. For example, components or subassemblies corresponding to manufacturing908are fabricated or manufactured like components or subassemblies produced while aircraft902is in service. Also, one or more apparatus examples, method examples, or a combination thereof are utilized during manufacturing908and system integration910, for example, by substantially expediting assembly of or reducing the cost of an aircraft902. Similarly, one or more apparatus examples, method examples, or a combination thereof are utilized while aircraft902is in service, for example, and without limitation, to maintenance and service916.

Further Examples

Further, the description includes examples according to the following clauses:

Clause 1. A method for decontaminating a cabin of an aircraft and providing an indication that the cabin is safe for reentry, the method comprising:

receiving a decontamination request at a controller;

determining, at the controller, operating parameters of one or more air conditioning packs and one or more fans of the aircraft,wherein the operating parameters comprise at least a duration of operating the one or more air conditioning packs and the one or more fans, andwherein the duration of operating the one or more air conditioning packs and the one or more fans is determined based on at least a cabin volume of the aircraft, a combined ventilation rate provided by the air conditioning packs and the one or more fans, and a remaining air threshold in the aircraft;

operating the one or more air conditioning packs and the one or more fans in accordance with the operating parameters thereby decontaminating the cabin; and

providing a completion indication to an indicator upon completion decontaminating the cabin.

Clause 2. The method of clause 1, wherein the decontamination request is received from an input device, communicatively coupled to the controller, wherein the input device is one of a flight deck switch or an attendant panel.

Clause 3. The method of any one of clause 1 or clause 2, wherein the decontamination request is received from one or more biosensors, positioned within a cabin of the aircraft.

Clause 4. The method of clause 3, wherein the decontamination request comprises a contaminant concentration input, exceeding a set threshold.

Clause 5. The method of any one of clauses 1-4, wherein the operating parameters further comprise an operating output of each of the one or more air conditioning packs and each of the one or more fans.

Clause 6. The method of clause 5, wherein the operating output of each the one or more air conditioning packs and each of the one or more fans varies while operating the one or more air conditioning packs and the one or more fans.

Clause 7. The method of any one of clauses 1-6, further comprising:

receiving, at the controller and from one or more biosensors positioned in a cabin of the aircraft and while operating the one or more air conditioning packs and the one or more fans, contaminant concentration in the cabin; and

revising the operating parameters based on the contaminant concentration in the cabin.

Clause 8. The method of any one of clauses 1-7, further comprising receiving, at the controller and from one or more door sensors, a door closure input, corresponding to an open-close position of each cabin door.

Clause 9. The method of clause 8, wherein operating the one or more air conditioning packs and the one or more fans is initiated based on the door closure input.

Clause 10. The method of clause 8, wherein the operating parameters of the one or more air conditioning packs and the one or more fans are further determined based on the door closure input.

Clause 11. The method of any one of clauses 1-10, wherein the completion indicator is located on the outside of the aircraft and visible to persons outside the aircraft.

Clause 12. The method of any one of clauses 1-11, wherein the completion indicator is located on one or more of a jet bridge, a jet bay, or an airport gate, and visible to persons outside the aircraft.

Clause 13. The method of any one of clauses 1-12, wherein the completion indicator comprises or is coupled to a wireless transmitter.

Clause 14. The method of any one of clauses 1-13, wherein at least operating the one or more air conditioning packs and the one or more fans is performed while the aircraft is grounded.

Clause 15. The method of any one of clauses 1-14, wherein at least operating the one or more air conditioning packs and the one or more fans is performed when the cabin of the aircraft is empty and free of occupants.

Clause 16. The method of any one of clauses 1-15, further comprising confirming that the cabin of the aircraft is empty and free of occupants before performing operating the one or more air conditioning packs and the one or more fans.

Clause 17. A system for decontaminating a cabin of an aircraft and providing an indication that the cabin is safe for reentry, the system comprising:

one or more air conditioning packs, configured to receive ambient air from outside the aircraft and to supply the ambient air into the cabin of the aircraft;

one or more filters;

one or more fans, configured to receive cabin air from the cabin of the aircraft, to pass the cabin air through the one or more filters thereby generating filtered air, and to supply the filtered air into the cabin;

a controller, communicatively coupled to the one or more air conditioning packs and to the one or more fans and configured to receive a decontamination request and to determine operating parameters of one or more air conditioning packs and one or more fans to perform decontamination,wherein the operating parameters comprise duration of operating the one or more air conditioning packs and the one or more fans, andwherein the duration of operating the one or more air conditioning packs and the one or more fans is determined based on one or more of (a) a cabin volume of the aircraft, (b) a combined ventilation rate provided by the one or more air conditioning packs and the one or more fans, and (c) an acceptable fraction of remaining air in the aircraft; and

an indicator, communicatively coupled to the controller and configured to receive completion indication from the controller and present to the completion indication to the indicator to indicate that the cabin is safe for reentry.

Clause 18. The system of clause 17, further comprising an input device, communicatively coupled to the controller and configured to send a decontamination request to the controller, wherein the input device is one of a flight deck switch or an attendant panel.

Clause 19. The system of any one of clause 17 or clause 18, further comprising one or more biosensors, positioned within the cabin of the aircraft, communicatively coupled to the controller, and configured to provide contamination concentration input to the controller.

Clause 20. The system of clause 19, wherein the controller is configured to use the contamination concentration input to trigger operation of the one or more air conditioning packs and the one or more fans.

Clause 21. The system of clause 19, wherein the controller is configured to use the contamination concentration input to revise the operating parameters of the one or more air conditioning packs and the one or more fans.

Clause 22. The system of any one of clauses 17-21, wherein the operating parameters further comprise an operating output of each of the one or more air conditioning packs and each of the one or more fans.

Clause 23. The system of any one of clauses 17-22, further comprising one or more door sensors, positioned at each cabin door, communicatively coupled to the controller, and configured to provide door closure input, corresponding to an open-close position of each cabin door, to the controller.

Clause 24. The system of clause 23, wherein the controller is configured to operate the one or more air conditioning packs and the one or more fans is initiated based on the door closure input.

Clause 25. The system of clause 23, wherein the operating parameters of the one or more air conditioning packs and the one or more fans are further determined based on the door closure input.

Clause 26. The system of any one of clauses 17-25, wherein the completion indicator is located on the outside of the aircraft190and visible to persons outside the aircraft.

Clause 27. The system of any one of clauses 17-26, wherein the completion indicator is located on one or more of a jet bridge, a jet bay, or an airport gate, and visible to persons outside the aircraft.

Clause 28. The system of any one of clauses 17-27, wherein the completion indicator comprises or is coupled to a wireless transmitter.

CONCLUSION

Although the foregoing concepts have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatus. Accordingly, the present examples are to be considered illustrative and not restrictive.