WO2016156835A1

WO2016156835A1 - Position indicator beacon

Info

Publication number: WO2016156835A1
Application number: PCT/GB2016/050886
Authority: WO
Inventors: Faris Samarai
Original assignee: Caledonian Airborne Systems Ltd.
Priority date: 2015-04-02
Filing date: 2016-03-30
Publication date: 2016-10-06
Also published as: GB2536957A; GB201505731D0

Abstract

The invention relates to a position indicator beacon apparatus which is deployable from a stricken aircraft in order to aid its location. The apparatus comprises a buoyant container; a transmitter that is switchably connected to a power source within the container; and a transmitting antenna connected to the transmitter. The buoyant container is attached to a deployable pre-existing external component of an aircraft's fuselage.

Description

POSITION INDICATOR BEACON

The present invention relates to a position indicator beacon and apparatus for its deployment, and particularly, but not exclusively, to a position indicator beacon which is deployable from a stricken aircraft to aid location thereof in an emergency.

It is already known to provide position indicators on aircraft which are either manually deployable by the flight crew, or automatically deployable in the event of a crash and/or submersion in water. For example, the present applicant's CPT-900 Emergency Locator Transmitter is mountable on a helicopter's fuselage or tail boom and, when activated, emits VHF and UHF homing and satellite compatible signals. When manually deployed whilst the helicopter is still airborne, its beacon is ejected downwards and rearwards, clear of the main and tail rotors and activates within eight seconds of contact with water. However, activation can also be effected whilst the beacon is fixed to the helicopter, either manually from the cockpit, or following a deceleration event in excess of a predetermined threshold.

Position indicators of the type described above are mounted externally on aircraft and covered by a carrier shroud and nose fairing so as to afford a degree of environmental protection to the beacon and its associated componentry. Whilst careful positioning of the carrier shroud and nose fairing is necessary - e.g. to ensure that the beacon's ejection trajectory avoids rotors [including during autorotation , radio aerials etc. - there will usually be a wide selection of suitable mounting points on a helicopter which do not adversely affect flight or operating characteristics. However, extremely rigorous safety standards imposed by regulatory bodies such as the European Aviation Safety Agency [EASA] and the Civil Aviation Authority [CAA present significant challenges for use of position indicators of the aforementioned type. In particular, the mounting of such position indicators to a fixed wing aircraft constitutes a significant design modification which will necessarily cause aerodynamic changes to the external fuselage. Inevitably, the proposed modification would necessitate expensive and often protracted testing and re-certification processes to be completed in order to meet the significantly more stringent safety approvals necessary for commercial fixed wing aircraft carrying fare- paying passengers or cargo.

It is an aim of the present invention to provide an improved position indicator beacon apparatus which overcomes, or at least ameliorates, one or more of the aforementioned problems.

According to a first aspect of the present invention there is provided position indicator beacon apparatus which is selectively deployable from a stricken aircraft to aid its location, the apparatus comprising:

(f) a buoyant container;

(if) a transmitter switchably connected to a power source within the container; and

(iif) a transmitting antenna connected to the transmitter;

wherein the buoyant container is attached to a deployable pre-existing external component of an aircraft's fuselage.

In the context of the present invention, the term "pre-existing external component" should be construed as meaning any removable extant part, panel or component of an aircraft having an external aerodynamic surface which has not been specifically provided or substantially externally modified to accommodate the beacon or its buoyant container.

Optionally, the position indicator beacon apparatus further comprises a GPS device. The GPS device may be integrated with the antenna (or multiple antennae) such that, once deployed on water, the location of the position indicator beacon apparatus is continually updated and detectable by both airborne and surface vessels.

Optionally, the position indicator beacon apparatus further comprises detection means for detecting one or more of altitude, deceleration and water. In an effort to address the potential problem of inadvertent deployment of the beacon apparatus [i.e. separation of the pre-existing external component and attached beacon from an aircraft's fuselage], certain deployment protocols can be established. In particular, it may be desirable to ensure that deployment only occurs when an aircraft has crashed or ditched into the sea. By incorporating an altitude switch and/or a G-switch and/or a hydrostatic switch and/or a saline switch within the apparatus, the desired deployment protocols can be controlled. It will be appreciated that if there is a requirement for all three switches (or at least two of them) to be activated then the risk of inadvertent deployment can be reduced, i.e. the chances of two or more switches simultaneously failing to operate as intended is very small indeed.

Optionally, at least part of the position indicator beacon apparatus is housed within a concavity formed within a pre-existing external component of an aircraft's fuselage. Optionally, the exterior skin of the pre-existing external component conforms to the existing aerodynamic profile of a surrounding aircraft fuselage.

Optionally, the pre-existing external component is attachable to an aircraft's fuselage by fusable fasteners.

Optionally, the pre-existing external component is hingeably attachable to an aircraft's fuselage.

Optionally, the pre-existing external component is a door, hatch or panel.

For example, commercial aircraft are already provided with numerous doors, hatches and panels of varying sizes which already meet the stringent safety approvals necessary for commercial fixed wing aircraft carrying fare-paying passengers or cargo. These may include, for example, passenger access doors, emergency exit doors, cargo door panels, maintenance/inspection panels, access panels for the undercarriage, and the like.

Optionally, the minimum length and width dimensions of the pre-existing external component are each 21 cm. Such dimensions could, in theory, accommodate a beacon which is no larger than the aforementioned CPT-900 Emergency Locator Transmitter if stowed in a manner such that its longitudinal axis extends substantially transverse to the external surface the preexisting external component. However, it is envisaged that the pre-existing external component would be a door, hatch or panel providing larger access sufficient for ground engineers to enter the empennage part of an aircraft. Accordingly, the length and width dimensions would then be of the order of 100 cm or more, and thus would provide more flexibility in terms of the orientation and size of the beacon relative to the external surface of the door, hatch or panel.

Optionally, the buoyant container further comprises a conventional cockpit voice recorder (CVR) and/or a conventional digital flight data recorder [DFDR .

Optionally, information stored within the cockpit voice recorder and/or digital flight data recorder is receivable via an umbilical or infrared link.

Advantageously, the use of an infrared link obviates the need for any physical wiring between the position indicator beacon apparatus and the remainder of the aircraft.

Optionally, the buoyant container comprises an Automatic Identification System (AIS) transmitter.

By incorporating an AIS VHF transmitter within the buoyant container, this will enable the reception of data by surface vessels and maritime patrol aircraft utilising Search and or Synthetic Aperture Radar (SARJ. The data received may include surface speed, GPS location, and alphanumeric aircraft registration or "tail number" detectable by both Airborne and Surface vessels.

Optionally, the position indicator beacon apparatus further comprises a radar transponder switchably connected to the power source an adapted such that, upon receipt of an incoming radar signal, it generates and transmits an enhanced radar response. Optionally, the radar transponder is disposed in an upper water-impervious part of the buoyant container which is pervious to radio and radar signals.

Optionally, the antenna is disposed proximate the transponder within said upper water- impervious part of the buoyant container.

Optionally, the antenna is a surface mount antennae.

Optionally, the transmitter is a VHF and/or UHF and/or FM transmitter.

Optionally, the power source is coupled to the transmitter and transponder through common hydrostatic switch and/or saline switch arranged within the buoyant container below its waterline so as to automatically energise and activate the beacon when it is deployed on water.

Optionally, a test button is operable from the exterior of the pre-existing external component in order to provide Built-in Test (BITE) functionality.

Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams, in which:-

Fig. 1 is a schematic side view of a position indicator beacon apparatus (partially exposing its inner componentry) in an upright position after deployment from a stricken aircraft; Fig. 2 is a schematic view showing the arrangement of the transmitter and transponder assembly within the position indicator beacon apparatus of Fig. 1; and

Fig. 3 is a schematic representation of the position indicator beacon apparatus of the present invention incorporated within a space formed in a pre-existing aircraft inspection panel. The beacon of Figure 1 comprises a buoyant container 1 with a lower cylindrical extension 30 defining a compartment for a battery 8 for operating radio transmitters and a radar transponder. The container 1 is formed of material pervious to high frequency radiation in the VHF/UHF and radar range and contains an upper surface mounted transmitting antenna 5 and radar transponder 6 [see Fig. 2). The buoyant container 1 may be formed, at least in those parts which are exposed when the beacon is floating, of fluorescent orange [Federal Standard 595a) fire-resistant heavy gauge polyethylene to define an environmentally sealed container. The cylindrical extension 30 of beacon 1 is fastened to a pre-existing aircraft inspection panel 40 such that the beacon is safely concealed within the aircraft during normal flight conditions. The exterior skin 42 of the panel 40 is industry standard and hence conforms to the surrounding aerodynamic profile of the surrounding aircraft fuselage. The panel 40 may be attached to the aircraft fuselage by a hinge at its forward end, or by means of fusable bolts around its periphery. The antenna 5 is coupled to one or more transmitters 7 [see Fig. 2) mounted within the buoyant container 1 and energised by a battery 8 through a switch 9. The transponder 6 and transmitter [s] 7 contained within buoyant container 1 are connected to the battery power source 8 via operating circuitry 26 connected to power management circuitry 25 and the switch 9. The switch 9 may be a hydrostatic switch or a saline switch arranged to automatically close and energise the transmitter [s 7 upon exposure to water [salt water or fresh water). As a safeguard against inadvertent closure of the switch 9, it may have a requirement for the beacon to first be orientated within 40 degrees of vertical, i.e. the switch will only close after the beacon is deployed in its upright floating configuration. Alternative switches, or two or more different types of switches, may be provided. For example, the hydrostatic switch or saline switch may be replaced with, or supplemented by, an inertial switch [G-switch] or frangible switch adapted to close and energise the transmitter [s] 7 upon a deceleration event above a predetermined threshold level. The aforementioned switch types may be replaced with, or supplemented by an altitude switch adapted to close and energise the transmitter [s 7 upon detection of an altitude at or below a predetermined threshold level, which may be sea level. It will be appreciated that by simultaneously employing multiple switches of different types in series, the risk of inadvertent energising of the transmitter [s 7 can be greatly reduced.

In one embodiment, the battery 8 is mounted in a lower part of the buoyant container 1 to act as ballast and aid upright floating of the beacon on water. A hydrostatic switch 9 is employed and is operable when the lower portion of the buoyant container 1 is immersed with the beacon floating in an upright position within 40 degrees of vertical after a predetermined minimum period of 8 seconds. The beacon is adapted to float with the antenna 5 above water level and the hydrostatic switch 9 exposed to water through a sealed aperture.

A suitable VHF/UHF antenna is BURNDEPT Model 522 adapted to operate in the international distress frequencies of 121.5 and 24MHz, a suitable screened VHF/UHF transmitter is BURNDEPT 121.5, 243 Model 522 operating with carrier frequencies of 121.5 and 243 MHz and a suitable radar transponder is an X BAND MITSUBISHI MELSART Model H.9.5 GHz operating at 9.3 to 9.5 GHz.

The VHF/UHF transmitter BURNDEPT 121.5, 243 Model 522 operating with BURNDEPT VHF/UHF antenna Model 522 transmitting a radio distress signal has been found to be detectable by airborne receivers of appropriate specification up to a distance of 80 nautical miles.

The VHF/UHF transmitter is suitably provided with test load circuitry connectable to a test panel 27 through contacts 28 exposed externally of the container 1. The test circuitry is powered by the beacon's own battery 8 whereby testing of the efficacy of the transmitter may be effected before operation of the aircraft, helicopter or other vehicle or vessel. The test circuity is also applied to the transponder 6 for like purposes. Conveniently, the test functionality is manually operable via a button provided in a recessed portion of the exterior of the pre-existing external component and hence provides Built-in Test (BITE] functionality. The radar transmitter of the transponder 6 is operatively coupled to a sawtooth generator adapted when the transponder 6 is receiving a radar signal - for example, a signal from the weather radar of a search aircraft - to cause the transmitter of the transponder 6 to generate a series of enhanced radar signals in the 9.3 to 9.5 GHz band, this band range being compatible with all commercially available aircraft and marine radars. In one embodiment, the sawtooth generator is adapted to generate an operating frequency of 20 repetitions in 100 microseconds at a sweep frequency sawtooth spacing of 5 microseconds nominal, the enhanced radar signals showing an antenna gain of 3dB. As a result, when the beacon is in the line of sight-range it will recognise interrogation of the weather radar of the searching aircraft and reply or echo with a unique response pattern signal of 20 equally spaced pulses which will be represented on a radar display as 20 equally spaced blips extending outwardly from the beacon in 0.4 nautical mile increments. The display signal is readily distinguishable from other normal radar echos and against heavy sea clutters and enables the location of the beacon to be pin-pointed from ranges of 39 nautical miles on radar. As a result a search aircraft may initially home on the radio signal and on detection of the coded radar coded signal can precisely pin-point the beacon position.

Also contained within the buoyant container 1 is a digital flight data recorder and/or cockpit voice recorded 33 connected to contacts 34 exposed externally of the buoyant container 1 and which are adapted for operative connection to a present position indicator of an aircraft. As such, present position data may be recorded and also other flight or passage data relevant to safe flight or passage prior to deployment of the beacon. The recorder 33 is coupled to the radio transmitter 7 so that the carrier signals may be modulated to give a latest present position signal at the time the beacon is activated by the hydrostatic switch 9 [and/or other switches) after deployment. Flight data recording may be stored in digital form to be retrieved by down loading to a ground based computer. In use, if it is established by the predetermined deployment protocols that a crash or an emergency ditching in water has occurred, the door, panel or hatch 40 to which the beacon is attached is deployed; that is to say it is actively separated from the surrounding aircraft fuselage. For example, separation may occur as a result of explosive charges adapted to shear hinges and/or fusable bolts which connect the panel 40 to the surrounding fuselage. Upon shearing of the fusable bolts, one or more compression springs attached to the fuselage may urge the panel 40 away from the fuselage. Combustion gas from an electrically ignited fuse or flare may be employed to generate pressure acting on the panel's periphery to assist its separation from the fuselage.

Once separated from the fuselage, the mass distribution of the apparatus is such that its centre of gravity and / or centre of buoyancy is offset towards the door, panel or hatch 40 at a point which lies below the waterline. This enhances the overall stability of the beacon and ensures that it will have a tendency to return to an upright orientation such that its antenna 5 faces the sky.

Although particular embodiments of the invention have been disclosed herein in detail, this has been done by way of example and for the purposes of illustration only. The aforementioned embodiments are not intended to be limiting with respect to the scope of the appended claims. Indeed, it is contemplated by the inventor that various substitutions, alterations, and modifications may be made to the invention without departing from the scope of the invention as defined by the claims.

Claims

1. A position indicator beacon apparatus which is selectively deployable from a stricken aircraft to aid its location, the apparatus comprising:

(ij a buoyant container;

(if) a transmitter switchably connected to a power source within the container; and (iif) a transmitting antenna connected to the transmitter;

2. A position indicator beacon apparatus according to claim 1, further comprising a GPS device.

3. A position indicator beacon apparatus according to claim 1 or 2, further comprising detection means for detecting one or more of altitude, deceleration and water.

4. A position indicator beacon apparatus according to any preceding claim, wherein at least part of the position indicator beacon apparatus is housed within a concavity formed within a pre-existing external component of an aircraft's fuselage.

5. A position indicator beacon apparatus according to any preceding claim, wherein the exterior skin of the pre-existing external component conforms to the existing aerodynamic profile of a surrounding aircraft fuselage

6. A position indicator beacon apparatus according to any preceding claim, wherein the pre-existing external component is attachable to an aircraft's fuselage by fusable fasteners.

7. A position indicator beacon apparatus according to any preceding claim, wherein the pre-existing external component is hingeably attachable to an aircraft's fuselage at its forward end.

8. A position indicator beacon apparatus according to any preceding claim, wherein the pre-existing external component is a door, hatch or panel.

9. A position indicator beacon apparatus according to any preceding claim, wherein the minimum length and width dimensions of the pre-existing external component are each 21 cm.

10. A position indicator beacon apparatus according to any preceding claim, wherein the buoyant container further comprises a conventional cockpit voice recorder [CVR] and/or a conventional digital flight data recorder (DFDRJ.

11. A position indicator beacon apparatus according to claim 10, wherein information stored within the cockpit voice recorder and/or digital flight data recorder is receivable via an umbilical or infrared link.

12. A position indicator beacon apparatus according to any preceding claim, wherein the buoyant container comprises an Automatic Identification System (AIS) transmitter.

13. A position indicator beacon apparatus according to any preceding claim, wherein the position indicator beacon apparatus further comprises a radar transponder switchably connected to the power source an adapted such that, upon receipt of an incoming radar signal, to generate and transmit an enhanced radar response.

14. A position indicator beacon apparatus according to claim 13, wherein the radar transponder is disposed in an upper water-impervious part of the buoyant container which is pervious to radio and radar signals.

15. A position indicator beacon apparatus according to claim 14, wherein the antenna is disposed proximate the transponder within said upper water-impervious part of the buoyant container.

16. A position indicator beacon apparatus according to claim 14 or 15, wherein the antenna is a surface mount antennae.

17. A position indicator beacon apparatus according to any preceding claim, wherein the transmitter is a VHF and/or UHF and/or FM transmitter.

18. A position indicator beacon apparatus according to any preceding claim, wherein the power source is coupled to the transmitter and transponder through common hydrostatic switch and/or saline switch arranged within the buoyant container below its waterline so as to automatically activate the beacon when it is deployed on water.

19. A position indicator beacon apparatus according to any preceding claim, wherein a test button is operable from the exterior of the pre-existing external component in order to provide Built-in Test (BITE) functionality.