WO2023164739A1

WO2023164739A1 - Tank assembly and helicopter

Info

Publication number: WO2023164739A1
Application number: PCT/AU2023/050102
Authority: WO
Inventors: Jason Schellaars
Original assignee: Helitak Fire Fighting Equipment Pty Ltd
Current assignee: Helitak Fire Fighting Equipment Pty Ltd
Priority date: 2022-03-01
Filing date: 2023-02-15
Publication date: 2023-09-07
Anticipated expiration: 2024-09-01

Abstract

A tank assembly for a helicopter is disclosed herein. The helicopter has a fuselage with at least two spaced-apart longitudinal floor beams and at least one lateral floor member extending therebetween. The tank assembly comprises a retractable tank for storing liquid or other substances. The retractable tank comprises an upper frame structure. The tank assembly further comprises at least two attachment devices, wherein each of the at least two attachment devices is mounted to the upper frame structure and configured to mount to a respective longitudinal floor beam at or near a junction of the respective longitudinal floor beam and the at least lateral floor member so as to suspend the retractable tank from the fuselage.

Description

TANK ASSEMBLY AND HELICOPTER

Technical Field

[0001] The present disclosure relates to a tank assembly for a helicopter, and more particularly, a tank assembly comprising a retractable tank for storing liquid or other substances. The present disclosure also relates to a helicopter with a tank assembly attached thereto, the tank assembly comprising a retractable tank for storing liquid or other substances.

Background

[0002] The Sikorsky S-92A helicopter is a twin-engine multi-purpose helicopter that has been used primarily for providing crew transportation in the offshore oil and gas industry as well as search and rescue operations due to its large cabin compartment, high fuel capacity, flexible configuration and manoeuvrability. However, due to declining revenue prospects in the oil and gas industry, operators are now exploring alternative uses for the Sikorsky S-92A helicopter, including use in aerial firefighting operations.

Summary

[0003] In accordance with an aspect of the present disclosure, there is provided a tank assembly for a helicopter having a fuselage with at least two spaced-apart longitudinal floor beams and at least one lateral floor member extending therebetween, the tank assembly comprising: a retractable tank for storing liquid or other substances, the retractable tank comprising an upper frame structure; and at least two attachment devices, wherein each of the at least two attachment devices is mounted to the upper frame structure and configured to mount to a respective longitudinal floor beam at or near a junction of the respective longitudinal floor beam and the at least lateral floor member so as to suspend the retractable tank from the fuselage.

[0004] Each of the at least two attachment devices may comprise a lower mount and an upper mount releasably attached to the lower mount. The lower mount may be fixedly secured to the upper frame structure and the upper mount may be fixedly securable to the respective longitudinal floor beam.

[0005] Each of the upper mounts may comprise a forward portion and a rearward portion spaced therefrom. The forward portion may define a plurality of apertures corresponding to a plurality of rivet holes of the respective longitudinal floor beam located forward of the junction, and the rearward portion may define a plurality of apertures corresponding to a plurality of rivet holes of the respective longitudinal floor beam located rearward of the junction.

[0006] The retractable tank may further comprise a moveable lower frame structure and a flexible bag connected to the upper and lower frame structures. The lower frame structure may be moveable between a first retracted position in which the lower frame structure is substantially within or adjacent the upper frame structure, and a second extended position in which the lower frame structure is spaced from the upper frame structure such that a volume is defined within the flexible bag for storing the liquid or other substances.

[0007] The lower frame structure may be biased to the first retracted position and may move towards the second extended position in response to the amount of liquid or other substance in the volume of the flexible bag.

[0008] The lower frame structure may be biased to the first retracted position by a retraction system engaged with the upper and lower frame structures.

[0009] In accordance with another aspect of the present disclosure, there is provided a helicopter comprising: a fuselage having at least two spaced-apart longitudinal floor beams and at least one lateral floor member extending therebetween; and a tank assembly comprising: a retractable tank for storing liquid or other substances, the retractable tank comprising an upper frame structure; and at least two attachment devices, wherein each of the at least two attachment devices is mounted to the upper frame structure and mounted to a respective longitudinal floor beam at or near a junction of the respective longitudinal floor beam and the at least lateral floor member so that the retractable tank is suspended from the fuselage.

[0010] Each of the at least two attachment devices may comprise a lower mount and an upper mount releasably attached to the lower mount. The lower mount may be fixedly secured to the upper frame structure and the upper mount may be fixedly secured to the respective longitudinal floor beam.

[0011] Each of the upper mounts comprises a forward portion and a rearward portion spaced therefrom. The forward portion may define a plurality of apertures corresponding to a plurality of rivet holes of the respective longitudinal floor beam located forward of the junction, and the rearward portion may define a plurality of apertures corresponding to a plurality of rivet holes of the respective longitudinal floor beam located rearward of the junction, such that fasteners may extend through the apertures and the rivets holes.

[0012] The at least one lateral floor member may comprise four lateral floor members, and the at least two attachment devices may comprise eight attachment devices.

[0013] The helicopter may be a Sikorsky S-92A helicopter.

[0014] The retractable tank may further comprise a moveable lower frame structure and a flexible bag connected to the upper and lower frame structures. The lower frame structure may be moveable between a first retracted position in which the lower frame structure is substantially within or adjacent the upper frame structure, and a second extended position in which the lower frame structure is spaced from the upper frame structure such that a volume is defined within the flexible bag for storing the liquid or other substances.

[0015] The lower frame structure may be biased to the first retracted position and may move towards the second extended position in response to the amount of liquid or other substance in the volume of the flexible bag.

[0016] The lower frame structure may be biased to the first retracted position by a retraction system engaged with the upper and lower frame structures. Brief Description of Drawings

[0017] Embodiments of the present disclosure will now be described hereinafter, by way of examples only, with reference to the accompanying drawings, in which:

[0018] Fig. 1 is a perspective view of an embodiment of a tank assembly, with a lower frame structure of the tank assembly being in a second extended position;

[0019] Fig. 2 is an exploded view of an attachment device of the tank assembly of Fig. 1;

[0020] Fig. 3 is a perspective view of the attachment device of Fig. 2;

[0021] Fig. 4 is a perspective view of the tank assembly of Fig. 1, with the lower frame structure of the tank assembly being in a first retracted position;

[0022] Fig. 5 is a perspective view of the tank assembly of Fig 1, indicating the direction of movement of the lower frame structure to the second extended position;

[0023] Fig. 6 is a perspective view of an embodiment of a helicopter with the tank assembly of Fig. 1 mounted thereto;

[0024] Fig. 7 is a schematic view of the helicopter of Fig. 6; and

[0025] Fig. 8 is an enlarged view of AA of Fig. 7.

Description of Embodiments

[0026] Fig. 1 shows an embodiment of a tank assembly 10 for a helicopter 20. The tank assembly 10 comprises a retractable tank 100 for storing liquid or other substances such as water or fire retardant material, for example. The retractable tank 100 comprises an upper frame structure 102, a moveable lower frame structure 104 and a flexible bag 106, in the form of a funnel-shaped bellows, which is connected to the upper and lower frame structures 102, 104. The upper frame structure 102 has a forward end portion 108, a rearward end portion 110, a centre portion 112 between the forward end portion 108 and the rearward end portion 110, and an upwardly-facing surface 114. The upwardly-facing surface 114 defines a plurality of openings 116. The upper and lower frame structures 102, 104 are formed from carbon fibre material or the like.

[0027] The tank assembly 10 also comprises at least two attachment devices 118 mounted to the upper frame structure 102. In this embodiment, the tank assembly 10 comprises eight attachment devices 118a- 118h; four of the attachment devices 118a, 118c, 118e, 118g are longitudinally aligned along a first side portion 120 of the upper frame structure 102 and four of the attachment devices 118b, 118d, 118f, 118h are longitudinally aligned along a second side portion 122 of the upper frame structure 102. Moreover, the attachment devices 118a, 118b are located in the forward end portion 108 of the upper frame structure 102, the attachment devices 118c, 118d, 118e, 118f are located in the centre portion 112 of the upper frame structure 102, and the attachment devices 118g, 118h are located in the rearward end portion 110 of the upper frame structure 102.

[0028] Each of the attachment devices 118a-l 18h comprises a lower mount 124 and an upper mount 126 releasably attached to the lower mount 124. With reference to Figs. 2 and 3, the lower mount 124 comprises a first member 128 having a centre opening 130, a first set of apertures 132 and a second set of apertures 134. The lower mount 124 further comprises a second member 136 having a base portion 138 and an attachment portion 140 which extends upwardly from the base portion 138. The base portion 138 defines a plurality of apertures 142 corresponding to the first set of apertures 132 of the first member 128. In this embodiment, the attachment portion 140 is in the form of a clevis defining two opposed laterally-extending apertures 144. The attachment portion 140 of the second member 136 extends upwardly through the centre opening 130 of the first member 128 and the first member 128 is fixedly secured to the second member 136 by bolts 146, for example, that extend through the first set of apertures 132 of the first member 128 and the plurality of apertures 142 of the base portion 138 of the second member 136. The second member 136 is fixedly secured to the upper frame structure 102 by bolts 148, for example, that extend through the second set of apertures 134.

[0029] The upper mount 126 comprises a forward portion 150 and a rearward portion 152 spaced from the forward portion 150. The forward portion 150 defines a plurality of apertures 154 and the rearward portion 152 defines a plurality of apertures 156. The upper mount 126 also comprises a downwardly-extending portion 158 that defines an aperture 160 therein and is releasably attached to the attachment portion 140 of the second member 136 by a fastener. In this embodiment, the fastener is in the form of a T-handle quick release pin 162 that extends transversely through each of the apertures 144 of the attachment portion 140 and the aperture 160 of the downwardly-extending portion 158 of the upper mount 126, thereby releasably attaching the upper mount 126 to the lower mount 124, as best shown in Fig. 3.

[0030] The attachment devices 118 are formed from aluminium such as 6061-T6 aluminium, for example, or the like.

[0031] Moreover, the tank assembly 10 comprises a retraction system (not shown) having a coil spring mechanism connected to the upper frame structure 102 and a pulley system operatively connected to the coil spring mechanism and the lower frame structure 104.

[0032] The lower frame structure 104 is moveable between a first retracted position and a second extended position. In the first retracted position, as shown in Fig. 4, the lower frame structure 104 is substantially within or adjacent the upper frame structure 102 and the flexible bag 106 is collapsed within the upper frame structure 102. The coil spring mechanism of the retraction system biases the lower frame structure 104 to the first retracted position. As liquid or other substances is introduced into the retractable tank 100 via a flexible inlet hose 300, the flexible bag 106 expands to define a volume therein for storing the liquid or other substances. The weight of the liquid or other substances in the flexible bag 106 causes the lower frame structure 104 to move by gravity to the second extended position in the direction A, as shown in Fig. 5. In the second extended position, the lower frame structure 104 is displaced downwardly from the upper frame structure 102. The extent of downward displacement of the lower frame structure 104 from the upper frame structure 102 is dependent on the volume of liquid or other substances stored in the flexible bag 106. Downward displacement of the lower frame structure 104 relative to the upper frame structure 102 also causes tension in the coil spring mechanism of the retraction system. In this embodiment, the volume of the flexible bag 106 is about 5,000 litres (1,320 US gallons) when the flexible bag 106 is fully expanded. The plurality of openings 116 in the upwardly-facing surface 112 allows for any overflow of liquid or other substances.

[0033] The tank assembly 10 further comprises two bomb doors (not shown) that are disposed at or adjacent the lower frame structure 104 for controlling the amount of liquid or other substances to be released from the flexible bag 106. Each of the bomb doors comprises a first end pivotably attached to the lower frame structure 104 and a second opposed free end. The bomb doors are pneumatically-operated via a controller (not shown). Each of the bomb doors is movable between a closed position in which the free end is at or substantially adjacent the lower frame structure 104, and an open position in which the free end is displaced downwardly from the lower frame structure 104 to allow the liquid or other substances to be released by gravity from the flexible bag 106. In some embodiments, the bomb doors may be controlled individually or simultaneously by the controller to provide various release patterns depending on fire suppression requirements. For example, the controller may provide Full Open, 1/2 Open, 1/3 Open or 1/4 Open modes. Additionally or optionally, the controller may also provide a Full Open failsafe mode, in which the bomb doors remain open to release all of the liquid or other substances stored in the flexible bag 106 in the event of any electrical faults or an emergency.

[0034] When either of the bomb doors are in the open position and the liquid or other substances is released from the flexible bag 106, the lower frame structure 104 automatically moves upwards towards the first retracted position due to the bias of the tension in the coil spring mechanism. It will be appreciated that the lower frame structure 104 will remain displaced from the upper frame structure 102 so long as liquid or other substances remain in the flexible bag 106.

[0035] Fig. 6 shows an embodiment of a helicopter 20 with the tank assembly 10 mounted thereto. The helicopter 20 may be a Sikorsky S-92A helicopter. The helicopter 20 comprises a fuselage 200 with a floor structure 202 (Fig. 7) formed from least two spaced-apart longitudinal floor beams 204 and at least one lateral floor member 206 that extends between the longitudinal floor beams 204. The underside of the floor structure 202 is covered with a fuselage skin 208 that is attached to at least the longitudinal floor beams 204 by rivets that extend through rivet holes 210 in the longitudinal floor beams 204.

[0036] The retractable tank 100 is suspended from the fuselage 200 of the helicopter 20 at eight mount locations AA. Each mount location AA corresponds to a junction of one of the longitudinal floor beams 204 and one of the lateral floor members 206, as shown in Fig. 7. With reference to Fig. 8, at each mount location AA, the upper mount 126 of the attachment device 118 is positioned such that the plurality of apertures 154 of the forward portion 150 are aligned with corresponding rivet holes 210 of the respective longitudinal floor beam 204 forward of the junction, and the plurality of apertures 156 of the rearward portion 152 are aligned with corresponding rivet holes 210 of the respective longitudinal floor beam 204 rearward of the junction. The upper mount 126 of the attachment device 118 is fixedly secured to the respective longitudinal floor beam 204 by way of fasteners. In this embodiment, each of the fasteners comprises a connecting pin 212 that extends through one of the apertures 154, 156 of the forward and rearward portions 150, 152 of the upper mount 126 and the corresponding rivet hole 210 of the respective longitudinal floor beam 204, and a locking member 214 that engages with the connecting pin 212. It will be appreciated that the fasteners will replace any existing rivets in the corresponding rivet holes 210 of the respective longitudinal floor beam 204. Fastening the upper mount 126 to the respective longitudinal floor beam 204 forward and rearward of the junction allows for the downward load on the respective longitudinal floor beam 204 to be distributed across the junction.

[0037] The retractable tank 100 may be released from the fuselage 200 of the helicopter 20 by disengaging the quick release pin 162 from the apertures 144 of the attachment portion 140 and the aperture 160 of the downwardly-extending portion 158 of the upper mount 126.

[0038] The controller for pneumatically-operating the bomb doors is located onboard the helicopter 20, specifically in the cockpit, to allow a pilot of the helicopter 20 to control the release of liquid or other substances stored in the flexible bag 106.

[0039] The embodiments described above has numerous advantages. For example, the tank assembly 10 provides a simple and effective retrofitting solution for adding firefighting capabilities to Sikorsky S-92A helicopters without requiring significant and expensive modifications to be made to the helicopters 20. By suspending the retractable tank 100 from the fuselage 200 of the helicopter 20 at the mount locations AA, via the attachment devices 118, the helicopter 20 is able to support the downward load of the tank assembly 10 with the fully expanded flexible bag 106, with a potential maximum lifting capacity in excess of 11,000 pounds (5000 kilograms). The downward load of the tank assembly 10 is also evenly distributed across the eight mount locations AA.

[0040] The tank assembly 10 is also easy to manufacture and can be easily attached to, and removed from, the helicopter 20. Further, the tank assembly 10 is designed such that it occupies minimal real-estate externally of the helicopter 20, thus not affecting the manoeuvrability and performance of the helicopter 20. For example, the lower frame structure 104 can be maintained in the first retracted position so that the retractable tank 100 does not obstruct ground movement of the helicopter 20, and the lower frame structure 104 is moveable to the second extended position to maximise the capacity of the flexible bag 106 when the helicopter 20 is airborne. Fitting the tank assembly 10 external to the helicopter 20 also allows the cargo compartment 406 of the helicopter 20 to be used for other purposes such as transporting persons or cargo.

[0041] Further still, the retraction system may be accessed externally by a user for adjustment and servicing via the plurality of openings 116 whilst the tank assembly 10 is attached to the helicopter 20, thus not requiring the tank assembly 10 to be removed from the helicopter 20. Moreover, the funnel shape of the expanded flexible bag 106 increases the head pressure of the retractable tank 100 to allow a more effective canopy penetration of the released liquid or other substances for extinguishing fires.

[0042] Using pneumatic systems to operate the bomb doors in the above embodiments also provides advantages over hydraulic systems. For example, in hydraulic systems, hydraulic pressures may continually produce errors in the electronics of the tank assembly 10 as constant minor changes in hydraulic pressure limits may cause excessive traffic between solenoids of the tank assembly 10, hydraulic pressure sensors and pilot control systems. These problems may be overcome or ameliorated by using pneumatic systems, rather than hydraulic system, to operate the bomb doors.

[0043] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A tank assembly for a helicopter having a fuselage with at least two spaced-apart longitudinal floor beams and at least one lateral floor member extending therebetween, the tank assembly comprising: a retractable tank for storing liquid or other substances, the retractable tank comprising an upper frame structure; and at least two attachment devices, wherein each of the at least two attachment devices is mounted to the upper frame structure and configured to mount to a respective longitudinal floor beam at or near a junction of the respective longitudinal floor beam and the at least lateral floor member so as to suspend the retractable tank from the fuselage.

2. The tank assembly according to claim 1, wherein each of the at least two attachment devices comprises a lower mount and an upper mount releasably attached to the lower mount, the lower mount being fixedly secured to the upper frame structure and the upper mount being fixedly securable to the respective longitudinal floor beam.

3. The tank assembly according to claim 2, wherein each of the upper mounts comprises a forward portion and a rearward portion spaced therefrom, the forward portion defining a plurality of apertures corresponding to a plurality of rivet holes of the respective longitudinal floor beam located forward of the junction, and the rearward portion defining a plurality of apertures corresponding to a plurality of rivet holes of the respective longitudinal floor beam located rearward of the junction.

4. The tank assembly according to any one of the preceding claims, wherein the retractable tank further comprises a moveable lower frame structure and a flexible bag connected to the upper and lower frame structures, and wherein the lower frame structure is moveable between a first retracted position in which the lower frame structure is substantially within or adjacent the upper frame structure, and a second extended position in which the lower frame structure is spaced from the upper frame structure such that a volume is defined within the flexible bag for storing the liquid or other substances.

5. The tank assembly according to claim 4, wherein the lower frame structure is biased to the first retracted position and moves towards the second extended position in response to the amount of liquid or other substance in the volume of the flexible bag.

6. The tank assembly according to claim 5, wherein the lower frame structure is biased to the first retracted position by a retraction system engaged with the upper and lower frame structures.

7. A helicopter comprising: a fuselage having at least two spaced-apart longitudinal floor beams and at least one lateral floor member extending therebetween; and a tank assembly comprising: a retractable tank for storing liquid or other substances, the retractable tank comprising an upper frame structure; and at least two attachment devices, wherein each of the at least two attachment devices is mounted to the upper frame structure and mounted to a respective longitudinal floor beam at or near a junction of the respective longitudinal floor beam and the at least lateral floor member so that the retractable tank is suspended from the fuselage.

8. The helicopter according to claim 7, wherein each of the at least two attachment devices comprises a lower mount and an upper mount releasably attached to the lower mount, the lower mount being fixedly secured to the upper frame structure and the upper mount being fixedly secured to the respective longitudinal floor beam.

9. The helicopter according to claim 7 or 8, wherein each of the upper mounts comprises a forward portion and a rearward portion spaced therefrom, the forward portion defining a plurality of apertures corresponding to a plurality of rivet holes of the respective longitudinal floor beam located forward of the junction, and the rearward portion defining a plurality of apertures corresponding to a plurality of rivet holes of the respective longitudinal floor beam located rearward of the junction, such that fasteners extend through the apertures and the rivets holes.

10. The helicopter according to any one of claims 7 to 9, wherein the at least one lateral floor member comprises four lateral floor members, and the at least two attachment devices comprises eight attachment devices.

11. The helicopter according to any one of claims 7 to 10, wherein the helicopter is a Sikorsky S-92A helicopter.

12. The helicopter according to any one of claims 7 to 11, wherein the retractable tank further comprises a moveable lower frame structure and a flexible bag connected to the upper and lower frame structures, and wherein the lower frame structure is moveable between a first retracted position in which the lower frame structure is substantially within or adjacent the upper frame structure, and a second extended position in which the lower frame structure is spaced from the upper frame structure such that a volume is defined within the flexible bag for storing the liquid or other substances.

13. The helicopter according to claim 12, wherein the lower frame structure is biased to the first retracted position and moves towards the second extended position in response to the amount of liquid or other substance in the volume of the flexible bag.

14. The helicopter according to claim 13, wherein the lower frame structure is biased to the first retracted position by a retraction system engaged with the upper and lower frame structures.