AIRCRAFT FIRE - EMERGENCY METHOD AND APPARATUS AND AIRCRAFT EQUIPPED THEREWITH

Abstract: A method and apparatus for preventing or reducing injury and loss of life and preventing, reducing or delaying damage to an aircraft in a fuel fire emergency involves supplying air under pressure from outside the aircraft to the aircraft interior to ventilate said interior, the aircraft being specially adapted to be connected to said air supply and having ducting to convey the pressurized air to the aircraft interior. Preferably the compressed air is in the form of a water mist.

Description: The present invention relates to aircraft fire-emergency method and apparatus and in particular to a method and apparatus for preventing or reducing injury and loss of life of passengers and crew of aircraft and preventing, reducing or delaying damage to the aircraft, in an emergency such as that following an accident to the aircraft and involving risk from fuel fire. The term aircraft as used in this specification includes both civil and military aircraft, including aeroplanes and helicopters, and also includes hovercraft. The risk to life as a result of fire in an aircraft accident which some or all of the occupants of the aircraft might otherwise have survived, has for some while been recognised as a serious problem, which has become all the more acute with larger numbers of passengers being capable of being carried in modern aircraft, many of the passengers being elderly people, children, invalids, or others who may not be well able to act quickly themselves to extricate themselves from the aircraft, assuming this is possible. A great deal of research has been carried out over many years relating to the survivability of the passengers and crew in fire related aviation accidents. Most of such accidents in fact occur either at airports or in the vicinity of airports, and therefore within reach of fire and rescue services. However, even when such services are immediately at hand, one of the most important factors affecting the survivability of passengers and crew within the aircraft is the very small amount of time available before fire, smoke, fumes and toxic gases can render the environment of the aircraft cabin unsurvivable. Most of the research effort hitherto towards reducing the problems concerned could be described as of a passive nature, being directed, for example, to the use of constructional and cabin materials within the aircraft which are more fire resistant than hitherto, and has been directed to increasing, albeit to only a minor degree, the short length of time which may be available for evacuating the aircraft. The concept of combating the problems from within the aircraft, rather than relying on the actions of the emergency services outside the aircraft does not, up to the present, appear to have been seriously considered in practical terms and it is one of the aspects of the present invention to enable this to be done. Specific hazards facing passengers and crew in event of fire are inhalation of toxic and/or hot gases; direct exposure to fire; the presence of smoke, which both reduces visibility and incapacitates if inhaled; flashover of the fire to within the cabin due to accumulation of combustible pyrolysis products within the cabin; and the possibility of further fuel explosions due to spread of the fire or heat to hitherto-unaffected fuel tanks. The concept of the present invention is to actively combat these hazards from within the aircraft itself, the aircraft having been specially adapted to enable this to be done. The invention enables the survivability of aircraft accidents to be considerablly improved by delaying or preventing the onset of the above-mentioned hazards. The use of air compressors and blowers for ventilation enclosed spaces such as manholes is already known and long established, for example from GB-1191393, and GB-A-2008740. The use of air compressors on board aircraft in the cabin pressurization equipment of the aircraft is also well-known and long established see, for example, GB-436546, GB-534523, and WO 85/04149. Additionally known, and under active development at the present time, are fire-emergency systems involving the supply of facemasks or smoke hoods to aircrew and passengers. See, for example, GB-A-2125534. Such masks have advantages and disadvantages, many of which will be self-evident. The method and apparatus of the present invention are not intended to replace other methods of combating aviation fire emergencies, but rather to compliment them. According to the present invention there is provided a method of preventing or reducing injury to, or loss of life of, passengers and crew in an aircraft and preventing, reducing or delaying damage to the aircraft, in an emergency in which there is risk of damage, injury or death resulting from a fuel fire, which method comprises - - operably connecting to the aircraft a means of supplying air under pressure to the aircraft; - said supply means being external to said aircraft; - said aircraft being adapted to receive air supply from said supply means, and - said aircraft being adapted to conduct said air supply to the interior of the aircraft; and - supplying air under pressure to the interior from said supply means to ventilate said aircraft interior. Also provided by the present invention is apparatus for use in a method of preventing or reducing injury to, or loss of life of, passengers and crew in an aircraft and preventing, reducing or delaying damage to the aircraft, in an emergency in which there is risk of damage, injury or death resulting from a fuel fire, which apparatus comprises - - means on board said aircraft adapted to be accessible from outside the aircraft to provide operable connection with a source of air under pressure exterior to the aircraft; and - ducting means in the aircraft for conveying said air under pressure from outside the aircraft to the interior of the aircraft to ventilate said aircraft interior. It will be understood that the scope of the invention extends to aircraft whenever fitted with apparatus according to the invention. The drawing is a perspective view, partially in section of a method and apparatus of the invention in use. Referring to the drawing, an aircraft 1 is equipped at 2 with operable connection means enabling a source of compressed air, in this case an airport rapid intervention fire vehicle 3 equipped with an air compressor, to be connected by means of the flexible conduit 4 to the connection means 2, and to supply air through vents 5 into the aircraft cabin 6. It will be appreciated that the air supplied to the aircraft cabin could conveniently be supplied by means of the aircraft's own air-conditioning system, if the aircraft is fitted with an air-conditioning system. In this case the apparatus of the invention is operably connected to the ducting of the air-­ conditioning system. However, for the purpose of the present invention, it is desirable that air is supplied to the cabin at or near floor level and accordingly, if the aircraft cabin does not already possess vents at or near the floor of the cabin, the apparatus of the present invention preferably comprises such vents 5 operably connected to the ducting means of the apparatus to supply air under pressure at or near the floor of the aircraft cabin. Additionally, or alternatively, it may be desirable to supply air under pressure near one or more of the doors, windows and/or hatches of the cabin in which case the apparatus of the invention will include suitably-positioned vents operably connected to the ducting means of the apparatus. The reason for such positioning is that it is of course desirable to prevent or reduce the flow of smoke and noxious and poisonous fumes and gases into the cabin from outside through any doors, windows or hatches which are open or broken. Preferably at least part of the air supplied to the interior of the aircraft cabin is in the form of a mixture with water as fine droplets, and to this end the apparatus of the invention may include a plurality of sprinkler heads positioned at the ceiling of the cabin. Each sprinkler head may be provided with heat sensor means to cause operation of such sprinkler head when a minimum temperature is reached. The purpose of supplying a water spray or mist to the interior of the aircraft cabin is not only to combat any conflagration which may already have started within the cabin but also to reduce or stabilise the temperature of the cabin, or at least reduce the rate at which the temperature may be rising, by virture of the latent heat of the evaporation of the moisture. Thus the cabin environment may be maintained at a tolerable temperature level for a longer period of time, and the risk of flashover of fire to the interior of the cabin may be reduced or delayed. It is a preferred feature of the method and apparatus of this invention that additional to and simultaneously with the supply of air to the aircraft cabin, any smoke or noxious fumes and gases which have ingressed are extracted from the aircraft cabin and to this end means may be provided, preferably in the form of vents at or near the ceiling of the cabin, for exhausting such smoke, fumes and gases from the cabin, being replaced ideally from the lower levels upwards by clean cold air from vents at or near floor level. An embodiment of the apparatus of the invention which may enable the method of the present invention to be performed with rescue service vehicles situated outside the area of immediate danger or risk surrounding the aircraft comprises one or more enclosed flexible fire-resistant conduits, which conduits are adapted to be stowed on board the aircraft and to be deployed in the event of emergency so that one end of the conduit, herein referred to as the aircraft end, is operably connected to the aircraft and the other end of the conduit, herein referred to as the services end, is or may be disposed at a distance from the aircraft, so as to enable the transfer of substances, messages and/or electricity to and/or from the aircraft. This form of apparatus may also comprise ejection means to enable the services end of the conduit to be ejected to a distance from the aircraft where it can be brought into use. The said ejection means may, for example, comprise a fire-resistant line or cable attached to the services end of the conduit and means being provided to propel said line or cable away from the aircraft, for example by means of a mechanical spring arrangement, gun, rocket or any other suitable means. A person or persons outside the aircraft could then pull said line or cable and the attached services end of the conduit to a position away from the aircraft, where the conduit can be brought into use. Alternatively, for example, the ejection means may comprise means adapted to urge the services end of the conduit itself away from the aircraft. Such means may also, of course, comprise the aforesaid mechanical spring means or one of the aforementioned explosive means, so that the rescue vehicle can be driven direct to the point where the services end of the conduit lands. Since the accident may occur at night, or otherwise in conditions of poor visibility, for example occasioned by smoke emitted from a fire resulting from the accident, it is desirable that the services end of the conduit is provided with means for emitting light and/or sound so that it can be readily located by the rescue services. Also it will be appreciated that it is desirable that the services end of the conduit is provided with a connector, preferably standardised, which is adapted to connect with a corresponding, preferably standardised, connector on a rescue vehicle or perhaps to an extension from the rescue vehicle, to enable transfer of the said substances, messages and/or electricity to and/or from the aircraft. The apparatus of the invention preferably includes means for connecting the aircraft to a source of electricity outside the aircraft, and where the apparatus comprises the afore-mentioned conduit it is envisaged that the conduit may incorporate one or more electrical wires or cables. These may be advantageously used by being connected to one or more of the lighting, intercom, cabin air-conditioning system and/or cabin sound electrical systems of the aircraft. The aircraft electrical systems may have suffered damage as a result of the accident, or may have been deliberately disconnected in view of risk of causing a fire or explosion. It may be desirable therefore to be able independently to supply electrical power to the aircraft to supplement or replace one or more of the above mentioned electrical systems or any other system which may be installed in the aircraft, e.g. smoke extractors, on the basis that power may be available. Furthermore, it will readily be appreciated that, for example, it may be highly desirable to be able to give instructions to the occupants of the aircraft from outside, particularly in the event that some or all of the crew of the aircraft have been incapacitated. Additionally, the sustenance of the other electrical systems of the aircraft may prove to be vital in providing sufficient time for evacuation. In the conduit form of the apparatus of the invention one or more of the conduits may be provided with at least two ducts for the passage of gases and/or liquids, so that two or more different fluids can be supplied to or removed from the aircraft simultaneously. This enables the conduit, for example, to simultaneously extract smoke, fumes and noxious gases from the cabin of the aircraft whilst supplying clean cool air and/or air/water mist through a second passageway to the cabin of the aircraft. It is not essential however for the conduit to contain more than one duct. In fact it may be of advantage, for a number of reasons, if only one duct is used. For example, this enables the conduit to be of smaller cross-section and to be more easily manageable. The desirability of a return duct may be avoided if means are provided at or on board the aircraft for exhausting smoke and fumes overboard using the power of the incoming pressure air, for example by using a venturi or a turbine. As has been mentioned previously, it is part of the concept of the present invention that fire, and the risk of fire, consequential to an aviation accident is tackled more actively, directly and simultaneously with any external attack on the fire by the rescue services, by means of equipment provided in the aircraft itself. To that end, the conduit of the apparatus of the present invention may be connected so as to supply inert gas, foam or other substances to voids in the fuel tanks and vents and/or engines of the aircraft so as to reduce the risk of fire, if it has not already occurred, or to reduce the risk of further spread of the fire or the risk of explosions of fuel-air mixtures in the interstices of the wings or engines of the aircraft, in particular surrounding the fuel tanks. It will be seen that in this way further damage to the aircraft can be prevented or reduced, or at least delayed, in addition to the more important use of the invention in protecting life and reducing injuries by extending the evacuation time. Although the concept of the present invention applies particularly to emergencies involving aircraft, it will be appreciated that the invention may also be adapted to meet similar problems in other fields, such as to provide aid to ships which may be in difficulties due to fire or flooding, and also to fixed installations, such as hotels and office buildings where fire at low level can present similar problems for personnel who may be trapped in other parts of the building.

Claims: 1. A method of preventing or reducing injury to, or loss of life of, passengers and crew in an aircraft and preventing, reducing or delaying damage to the aircraft, in an emergency in which there is risk of damage, injury or death resulting from a fuel fire, which method comprises - - operably connecting to the aircraft a means of supplying air under pressure to the aircraft; - said supply means being external to said aircraft; - said aircraft being adapted to receive air supply from said supply means, and - said aircraft being adapted to conduct said air supply to the interior of the aircraft; and - supplying air under pressure to the interior from said supply means to ventilate said aircraft interior. 2. A method as claimed in Claim 1 wherein the air is supplied to the interior of the aircraft at or near the floor of the cabin, and/or near one or more of the doors, windows and/or hatches of the aircraft. 3. A method as claimed in Claim 1 or Claim 2 wherein at least part of the air supplied to the interior of the aircraft cabin is in the form of a mixture with water as fine droplets. 4. A method as claimed in any one of the preceding claims wherein smoke and noxious fumes and gases are simultaneously extracted from the aircraft cabin, preferably at or near the ceiling of the cabin. 5. A method as claimed in any one of the preceding claims wherein simultaneously with the supply of air to the aircraft's cabin the aircraft is supplied with electricity from outside the aircraft to operate one or more of the aircraft's electrically operated systems. 6. A method as claimed in any one of the preceding claims wherein simultaneously with the connection and supply of air to the aircraft's cabin the aircraft's fuel tanks, fuel vents, engines and/or interstices of the aircraft's wings are supplied with an inert gas or liquid or a fire-retarding foam. 7. A method as claimed in any one of the preceding claims wherein an enclosed flexible fire-resistant conduit is stored on board the aircraft and is deployed in the event of emergency so as to provide convenient means for connection to the source of air under pressure and/or other services required by the aircraft. 8. Apparatus for use in the method as claimed in Claim 1, which apparatus comprises - - connection means on board said aircraft adapted to be accessible from outside the aircraft to provide operable connection with a source of air under pressure exterior to the aircraft; and - ducting means in the aircraft for conveying said air under pressure from outside the aircraft to the interior of the aircraft to ventilate said aircraft interior. 9. Apparatus as claimed in Claim 8 wherein the aircraft has an air-conditioning system and the apparatus is operably connected to the ducting of the air-conditioning system to supply air to the aircraft interior. 10. Apparatus as claimed in Claim 8 or Claim 9 wherein the apparatus comprises vents operably connected to said ducting means and positioned at or near the floor of the aircraft cabin, and/or positioned at one or more doors, windows and/or hatches in the aircraft cabin. 11. Apparatus as claimed in any one of Claims 8 to 10 including means whereby at least part of the air supply to the interior of the aircraft cabin is in the form of a mixture with water as fine droplets. 12. Apparatus as claimed in Claim 11 which comprises a plurality of sprinkler heads positioned at the ceiling of the cabin, each sprinkler head optionally having heat sensor means to cause operation of such sprinkler head when a minimum temperature is reached. 13. Apparatus as claimed in any one of the Claims 8 to 12 including means for extracting smoke and noxious fumes and gases from the interior of the aircraft cabin simultaneously with the supply of air under pressure to the cabin, the apparatus preferably comprising vents at or near the ceiling of the cabin. 14. Apparatus as claimed in any one of Claims 8 to 13 wherein means are provided for operably connected one or more of the aircraft's electrically operated systems to a source of electricity outside the aircraft. 15. Apparatus as claimed in any one of Claims 8 to 14 including means for operably connecting the fuel tanks, fuel vents, engines and/or interstices of the aircraft's wings with a supply of inert gas or liquid or fire-retarding foam. 16. Apparatus as claimed in any one of Claims 8 to 15; - said connection means comprising - - at least one enclosed flexible fire-resistant conduit - - said conduit being adapted to be stowed on board the aircraft and to be deployed in the event of emergency so that - - one end of the said conduit, herein referred to as the aircraft end, is operably connected to the aircraft and - the other end of said conduit, herein referred to as the services end, is capable of being disposed at a distance from the aircraft 17. Apparatus as claimed in Claim 16 further comprising ejection means for ejecting the servicing end of the conduit to a distance from the aircraft, the ejection means preferably comprising a fire-resistant line or cable to a distance from the aircraft to enable a cable attached to the services end of the conduit and means being provided to propel said line or cable to a distance from the aircraft to enable a person or persons outside the aircraft to pull the services end of the conduit to a suitable positioned away from the aircraft where the conduit can be brought into use, or alternatively said ejection means preferably comprising means adapted to urge the services end of the conduit itself away from the aircraft to a suitable position relative to the aircraft where the conduit can be brought into use. 18. Apparatus as claimed in Claim 16 or Claim 17 wherein the said services end of the conduit is provided with means for emitting light and/or sound. 19. Apparatus as claimed in any one of Claims 16 to 18 wherein said services end of the conduit is provided with a connector which is adapted to connect with a corresponding connector on or near a rescue vehicle to enable transfer of substances, messages and/or electricity to and/or from the aircraft. 20. Apparatus as claimed in any one of Claims 16 to 19 wherein said conduit incorporates one or more electrical wires or cables, and wherein said conduit is preferably connected to one or more of the lighting, intercom, cabin air conditioning system, and/or cabin sound electrical systems of the aircraft. 21. Apparatus as claimed in any one of Claims 16 to 20 wherein said conduit is provided with at least two ducts for passage of gases and/or liquids, the conduit preferably comprising a first passageway adapted for extracting smoke, fumes, and noxious gases from the cabin of the aircraft and a second passageway adapted for supplying clean air to the cabin of the aircraft. 22. Apparatus as claimed in any of Claims 16 to 20 in which said conduit comprises a single duct and wherein means are provided to exhaust smoke and fumes overboard, said means being provided by the power of the air supplied through the conduit to the aircraft. 23. Aircraft whenever fitted with apparatus as claimed in any one of Claims 8 to 22.

Inventors: BIRCH, NEVILLE HAMPTON
Applicants: THE BRITISH PETROLEUM COMPANY P.L.C.
Application year: 1986
Main classification: A62C3
IPC codes: B64D25, A62C3