ROTARY WING AIRCRAFT WITH A FUSELAGE AND A NON-RETRACTABLE SKID-TYPE LANDING GEAR

Abstract

A rotary wing aircraft with a fuselage and a non-retractable skid-type landing gear that is mounted to the fuselage, the non-retractable skid-type landing gear comprising at least one landing box, the at least one landing box being provided with a skid-type landing base member and an associated box shell that delimits an internal volume of the at least one landing box.

Claims

1. A rotary wing aircraft with a fuselage and a non-retractable skid-type landing gear that is mounted to the fuselage, wherein the non-retractable skid-type landing gear comprises at least one landing box, the at least one landing box being provided with a skid-type landing base member and an associated box shell that delimits an internal volume of the at least one landing box.

2. The rotary wing aircraft according to claim 1, wherein the associated box shell comprises an inboard shell section and an outboard shell section, the inboard shell section and the outboard shell section being integral with the skid-type landing base member or being at least rigidly attached to the skid-type landing base member.

3. The rotary wing aircraft according to claim 2, wherein the outboard shell section is adapted for defining a streamlined extension to a side shell of the fuselage.

4. The rotary wing aircraft according to claim 2, wherein the inboard shell section is adapted for defining a streamlined extension to a lower shell of the fuselage.

5. The rotary wing aircraft according to claim 1, wherein the at least one landing box comprises at least two main ribs that are at least essentially arranged perpendicularly to a longitudinal extension of the at least one landing box.

6. The rotary wing aircraft according to claim 5, wherein the at least one landing box comprises an at least essentially massive structural support member, the at least two main ribs being integral to the at least essentially massive structural support member or being at least rigidly attached to the at least essentially massive structural support member.

7. The rotary wing aircraft according to claim 1, wherein the at least one landing box is mounted by means of a screwed joint and/or a pin-in-lug joint to the fuselage.

8. The rotary wing aircraft according to claim 1, wherein the at least one landing box is adapted for carrying aircraft equipment arranged within the internal volume.

9. The rotary wing aircraft according to claim 1, wherein the at least one landing box is at least adapted for carrying emergency floatation devices arranged within the internal volume.

10. The rotary wing aircraft according to claim 1, wherein the at least one landing box is at least adapted for carrying at least one fuel tank arranged within the internal volume.

11. The rotary wing aircraft according to claim 1, wherein the at least one landing box is at least partially water tight.

12. The rotary wing aircraft according to claim 1, wherein the at least one landing box is detachably mounted to the fuselage.

13. The rotary wing aircraft according to claim 1, wherein the at least one landing box comprises a root width that is at least three times smaller than an overall aircraft width.

14. A non-retractable skid-type landing gear that is mountable to a fuselage of a rotary wing aircraft, comprising at least one landing box, the at least one landing box being provided with a skid-type landing base member and an associated box shell that delimits an internal volume of the at least one landing box.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Preferred embodiments of the invention are outlined by way of example in the following description with reference to the attached drawings. In these attached drawings, identical or identically functioning components and elements are labeled with identical reference numbers and characters and are, consequently, only described once in the following description.

[0049] FIG. 1 shows a side view of an aircraft with a fuselage and a non-retractable skid-type landing gear according to the present invention,

[0050] FIG. 2 shows a top view of the aircraft of FIG. 1,

[0051] FIG. 3 shows a side view of the aircraft of FIG. 1 with the highlighted non-retractable skid-type landing gear,

[0052] FIG. 4 shows a side view of the aircraft of FIG. 1 with the detached non-retractable skid-type landing gear,

[0053] FIG. 5 shows a side view of the aircraft of FIG. 1 with the non-retractable skid-type landing gear and schematically illustrated mounting structures,

[0054] FIG. 6 shows a front view of the aircraft of FIG. 1,

[0055] FIG. 7 shows a sectional view of the aircraft of FIG. 6 with the detached non-retractable skid-type landing gear and a schematically illustrated first connection variant, and

[0056] FIG. 8 shows a sectional view of the aircraft of FIG. 6 with the detached non-retractable skid-type landing gear and a schematically illustrated second connection variant.

DETAILED DESCRIPTION OF THE INVENTION

[0057] FIG. 1 shows an aircraft 1 with a fuselage 2 and a non-retractable skid-type landing gear 10 that is mounted to the fuselage according to one aspect of the present invention. More specifically, the fuselage 2 illustratively comprises a fuselage underside 2a that is preferably at least partly connected to the non-retractable skid-type landing gear 10.

[0058] According to one aspect of the present invention, the non-retractable skid-type landing gear 10 comprises at least one landing box 10a (and 10b in FIG. 2). The latter preferentially defines a closed structural arrangement. Preferably, the at least one landing box 10a (and 10b in FIG. 2) is provided with a skid-type landing base member 10k and an associated box shell 10c that delimits an internal volume (10l in FIG. 7 and FIG. 8) of the at least one landing box 10a (and 10b in FIG. 2).

[0059] It should be noted that in the context of the present invention the expression “non-retractable skid-type landing gear” refers to any landing gear that is fixedly mounted to a fuselage and that is not adapted for being retracted into adequate storage compartments provided within the fuselage, or outside thereof within additional sponsons. Furthermore, the term “skid-type” in this expression is not intended for limiting the inventive landing gear to a landing gear with skids. More specifically, the skid-type landing base members 10k are not necessarily skids and can be implemented by any base member that is suitable for defining a contact surface and supporting an associated aircraft on ground. In other words, the skid-type landing base members 10k can be implemented by means of any bar-, rod- or lath-shaped element that is sufficiently strong for providing a required stability for an aircraft that is standing thereon on ground.

[0060] According to one aspect of the present invention, the at least one landing box 10a (and 10b in FIG. 2) of the non-retractable skid-type landing gear 10 is detachably mounted to the fuselage 2. In other words, the non-retractable skid-type landing gear 10 and, more specifically, the at least one landing box 10a (and 10b in FIG. 2), defines an individual exchangeable system module. Preferentially, the non-retractable skid-type landing gear 10 and, more specifically, the at least one landing box 10a (and 10b in FIG. 2), is mounted to the fuselage 2 at associated interconnection regions 10f.

[0061] Preferably, the at least one landing box 10a (and 10b in FIG. 2) is at least partially water tight and/or adapted for carrying aircraft equipment 9. By way of example, the at least one landing box 10a (and 10b in FIG. 2) is at least adapted for carrying emergency floatation devices 9a and/or at least one fuel tank 9b.

[0062] It should, however, be noted that the at least one landing box 10a (and 10b in FIG. 2) is not limited to carrying the emergency floatation devices 9a and/or the at least one fuel tank 9b. Instead, it can also be adapted for carrying any other required outboard equipment, such as optic sensorial systems, lights, live rafts, armament, etc., as well as e. g. damping devices.

[0063] Preferably, the at least one landing box 10a (and 10b in FIG. 2) comprises access openings 10e that are adapted for enabling access to the aircraft equipment 9 that is stored in the at least one landing box 10a (and 10b in FIG. 2). By way of example, the at least one landing box 10a (and 10b in FIG. 2) is equipped with, or implements, boarding steps 10d that are illustratively adapted for boarding and accessing the aircraft 1 via an aircraft door 7.

[0064] According to one aspect of the present invention, the at least one landing box 10a (and 10b in FIG. 2) exhibits a landing box basis 10g. More specifically, the landing box basis 10g is defined by the skid-type landing base member 10k and represents a predetermined landing contact area of the non-retractable skid-type landing gear 10, which illustratively extends longitudinally along a central portion of the aircraft 1 and e. g. corresponds at least approximately to a skid basis of a conventional skid-type landing gear.

[0065] The aircraft 1 is exemplarily embodied as a rotary wing aircraft and, more particularly, as a helicopter with at least one multi-blade main rotor 1a for providing lift and forward or backward thrust during operation. Therefore, the aircraft 1 is also referred to hereinafter as the “helicopter 1” for simplicity and clarity. It should, however, be noted that the present invention is not limited to helicopters and can likewise be applied to other aircrafts that can be equipped with a non-retractable skid-type landing gear according to the present invention.

[0066] For purposes of illustration, the helicopter 1 is shown with a first axis 8a in longitudinal direction, which is defined by the helicopter's roll axis that is inherent to the helicopter 1 and which is hereinafter referred to as the “roll axis 8a” for simplicity and clarity. The helicopter 1 is further shown with a second axis 8b in height direction, which is defined by the helicopter's yaw axis and which is hereinafter referred to as the “yaw axis 8b” for simplicity and clarity. Preferably, but not necessarily, the helicopter 1 is symmetrical about the yaw axis 8b and the roll axis 8a.

[0067] The at least one multi-blade main rotor 1a illustratively comprises a plurality of rotor blades 1b, 1c (and 1d, 1e in FIG. 2). The latter are mounted at an associated rotor head if that is arranged on top of the fuselage 2 to a rotor shaft, which rotates in operation of the helicopter 1 around an associated rotor axis.

[0068] Preferably, the fuselage 2 defines at least a cockpit 3a of the helicopter 1. Illustratively, the fuselage 2 further defines a cabin 3b of the helicopter 1 that is exemplarily accessible via the aircraft door 7 and that may further define one or more cargo compartments. Exemplarily, the cockpit 3a is also accessible via the aircraft door 7.

[0069] According to one aspect of the present invention, the fuselage 2 comprises a lower shell 3c, which is arranged in the region of the fuselage underside 2a, and side shells 3e that are arranged on each side of the helicopter 1. Preferably, the fuselage 2 further defines a tail boom 3d.

[0070] By way of example, the helicopter 1 comprises at least one preferentially shrouded counter-torque device 4 configured to provide counter-torque during operation, i. e. to counter the torque created by rotation of the at least one multi-blade main rotor 1a for purposes of balancing the helicopter 1 in terms of yaw. The at least one counter-torque device 4 is illustratively provided at an aft section of the tail boom 3d, which preferably further comprises a fin 5 and a horizontal tail 6.

[0071] FIG. 2 shows the helicopter 1 of FIG. 1 with the fuselage 2, the multi-blade main rotor 1a and the non-retractable skid-type landing gear 10. By way of example, the multi-blade main rotor 1a comprises in addition to the rotor blades 1b, 1c of FIG. 1 two more rotor blades, i. e. rotor blades 1d, 1e. The non-retractable skid-type landing gear 10 comprises in addition to the landing box 10a of FIG. 1 another landing box 10b, both of which are laterally arranged on the helicopter 1 and preferably similarly embodied, at least with respect to their basis configuration described above and hereinafter. It should be noted that the term “laterally arranged” refers in the context of the present invention to an arrangement in a lateral or sideward direction 8c of the helicopter 1, which is defined by the helicopter's pitch axis and which is hereinafter referred to as the “pitch axis 8c” for simplicity and clarity.

[0072] Illustratively, the helicopter 1 has an overall width 1g that is defined in direction of the pitch axis 8c by its fuselage 2 and the non-retractable skid-type landing gear 10 that is mounted to the fuselage 2. This overall width 1g is preferably considerably greater than a root width 10h of each one of the landing boxes 10a, 10b, preferentially at least three and illustratively at least five times greater, wherein the root width 10h is also defined in direction of the pitch axis 8c. Furthermore, each one of the landing boxes 10a, 10b illustratively comprises a root length 10i that is defined in direction of the roll axis 8a of the helicopter 1 and that is preferably also considerably greater than the root width 10h of each one of the landing boxes 10a, 10b, preferentially at least six times greater.

[0073] FIG. 3 shows the helicopter 1 of FIG. 1 and FIG. 2 with the fuselage 2, the multi-blade main rotor 1a and the non-retractable skid-type landing gear 10. Illustratively, the non-retractable skid-type landing gear 10 is highlighted and, more specifically, shown with a hatching in order to further illustrate a preferred size of the non-retractable skid-type landing gear 10, i. e. its landing boxes 10a, 10b, in relation to the fuselage 2.

[0074] FIG. 4 shows the helicopter 1 of FIG. 3 with the fuselage 2, the multi-blade main rotor 1a and the non-retractable skid-type landing gear 10. Illustratively, the non-retractable skid-type landing gear 10 is detached from the fuselage 2 so that the fuselage underside 2a and the lower shell 3c of the fuselage 2 are visible.

[0075] According to one aspect of the present invention, the non-retractable skid-type landing gear 10, i. e. its landing box 10a (and 10b in FIG. 5 to FIG. 8), comprises an interface perimeter 10j, which abuts to the fuselage underside 2a, i. e. the lower shell 3c of the fuselage 2, when the non-retractable skid-type landing gear 10, i. e. its landing box 10a (and 10b in FIG. 5 to FIG. 8) is mounted to the fuselage 2, as shown in FIG. 3, for example. Mounting is performed by means of suitable joints, as described below with reference to FIG. 7 and FIG. 8, between the non-retractable skid-type landing gear 10, i. e. its landing box 10a (and 10b in FIG. 5 to FIG. 8) and main attachment points 11 provided at the fuselage underside 2a, i. e. the lower shell 3c of the fuselage 2. These main attachment points 11 are preferably implemented as main load bearing parts.

[0076] In order to allow for an easy and comfortable mounting and dismounting of the non-retractable skid-type landing gear 10, i. e. its landing box 10a (and 10b in FIG. 5 to FIG. 8), the latter is provided with suitable main attachment access panels 12, preferably on each side. The latter are adapted to allow access to the main attachment points 11 provided at the fuselage underside 2a, i. e. the lower shell 3c of the fuselage 2, when the non-retractable skid-type landing gear 10, i. e. its landing box 10a (and 10b in FIG. 5 to FIG. 8) is mounted to the fuselage 2, as shown in FIG. 3, for example, so that dismounting is possible. Similarly, the main attachment access panels 12 can be used for accessing to the main attachment points 11 during mounting of the non-retractable skid-type landing gear 10, i. e. its landing box 10a (and 10b in FIG. 5 to FIG. 8), to the fuselage underside 2a, i. e. the lower shell 3c of the fuselage 2.

[0077] FIG. 5 shows the helicopter 1 of FIG. 1 to FIG. 3 with the fuselage 2, the multi-blade main rotor 1a and the non-retractable skid-type landing gear 10. Illustratively, the non-retractable skid-type landing gear 10 is shown as a transparent component for depicting constituent components thereof. The fuselage 2 is only partly shown as a transparent component for depicting two exemplary main frames 13 thereof, which are exemplarily arranged on each side of the aircraft door 7 and which are used for attachment of the non-retractable skid-type landing gear 10. However, more than two main frames 13 can likewise be provided.

[0078] According to one aspect of the present invention, the non-retractable skid-type landing gear 10 and, more specifically, the landing box 10a—and likewise the landing box 10b of FIG. 2—comprises at least two main ribs 12a that are preferably at least essentially arranged perpendicularly to a longitudinal extension of the landing box 10a, i. e. to its skid-type landing base member 10k. The at least two main ribs 12a are illustratively spaced apart by a predetermined distance 14 that is preferentially smaller than the landing box basis 10g of FIG. 1, which defines the length of the skid-type landing base member 10k.

[0079] Preferably, the at least two main ribs 12a of the landing box 10a are attached to the two main frames 13 of the fuselage 2 at the main attachment points 11 by means of suitable joints, as described below with reference to FIG. 7 and FIG. 8. The main attachment points 11 are exemplarily provided in the region of a floor level 3f of the helicopter 1.

[0080] FIG. 6 shows the helicopter 1 of FIG. 1 to FIG. 5 with the fuselage 2, the multi-blade main rotor 1a and the non-retractable skid-type landing gear 10. The latter comprises the landing box 10a of FIG. 1 to FIG. 5 and the landing box 10b of FIG. 2, which exemplarily define a U-shaped form with the fuselage 2. FIG. 6 further illustrates the overall width 1g of the helicopter 1, the root width 10h of the landing boxes 10a, 10b and the interface perimeters 10j of the landing boxes 10a, 10b that abut the fuselage 2 in the interconnection regions 10f.

[0081] FIG. 7 shows the helicopter 1 of FIG. 1 to FIG. 6 with the fuselage 2 that comprises the side shells 3e and the lower shell 3c, the multi-blade main rotor 1a and the non-retractable skid-type landing gear 10. The latter comprises the landing boxes 10a, 10b of FIG. 6. Illustratively, the landing box 10b is detached from the fuselage 2.

[0082] Preferably, at least the landing box 10a and, preferentially, both landing boxes 10a, 10b are provided with the skid-type landing base member 10k and the associated box shell 10c, as described above with reference to FIG. 1. The associated box shell 10c preferably delimits an internal volume 10l in each one of the landing boxes 10a, 10b.

[0083] The internal volume 10l is preferably at least essentially hollow and adapted for accommodating the aircraft equipment 9 of FIG. 1, as described above with reference to FIG. 1. In other words, the aircraft equipment 9 can be arranged within the internal volume 10l. Furthermore, the internal volume 10l preferentially accommodates, i. e. houses at least essentially the main ribs 12a of the landing boxes 10a, 10b of FIG. 5.

[0084] Preferably, at least one and, illustratively, each one of the landing boxes 10a, 10b comprises one or more at least essentially massive structural support members 18. The latter can be implemented by means of any rod-, bar- or lath-shaped members that comprise a required stiffness such that the one or more structural support members 18 are adapted for stiffening the landing boxes 10a, 10b and, thus, the non-retractable skid-type landing gear 10. Preferably, the at least two main ribs 12a of the landing boxes 10a, 10b are integral to the one or more structural support members 18, or they are at least rigidly attached thereto.

[0085] According to one aspect of the present invention, each associated box shell 10c comprises an inboard shell section 16a and an outboard shell section 16b, both of which delimit the internal volume 10l. The inboard shell section 16a and the outboard shell section 16b are preferably integral with the associated skid-type landing base member 10k, or they are at least rigidly attached to the associated skid-type landing base member 10k.

[0086] Illustratively, as can be seen with respect to the landing box 10a, the outboard shell section 16b is preferably adapted for defining a streamlined extension to the associated side shell 3e of the fuselage 2, i. e. a loft continuation of the latter. The inboard shell section 16a is preferably adapted for defining a streamlined extension to the lower shell 3c of the fuselage 2, i. e. a loft continuation of the latter.

[0087] According to one aspect of the present invention, the landing boxes 10a, 10b are mounted to the fuselage underside 2a, i. e. the lower shell 3c of the fuselage 2, by means of a screwed joint provided in a screwed joint region 15, which is further illustrated with respect to the detached landing box 10b. However, such a screwed joint is well known to the person skilled in the art and, therefore, not illustrated and described in greater detail, for simplicity and clarity of the drawings and brevity and conciseness of the description.

[0088] FIG. 8 shows the helicopter 1 of FIG. 1 to FIG. 6 with the fuselage 2 having the fuselage underside 2a, the multi-blade main rotor 1a and the non-retractable skid-type landing gear 10. The latter comprises the landing boxes 10a, 10b of FIG. 6. Illustratively, the landing box 10b is detached from the fuselage 2.

[0089] According to one aspect of the present invention, the landing boxes 10a, 10b are mounted to the fuselage underside 2a, i. e. the lower shell 3c of the fuselage 2, by means of a pin-in-lug joint provided in a pin-in-lug joint region 17, which is further illustrated with respect to the detached landing box 10b and wherein the pins are preferably oriented at least essentially in parallel to the roll axis 8a of FIG. 1. However, such a pin-in-lug joint is also well known to the person skilled in the art and, therefore, not illustrated and described in greater detail, for simplicity and clarity of the drawings and brevity and conciseness of the description.

[0090] It should be noted that modifications to the above described embodiments are within the common knowledge of the person skilled in the art and, thus, also considered as being part of the present invention. For instance, while it is mentioned that the landing boxes 10a, 10b are mounted to the fuselage underside 2a, i. e. the lower shell 3c of the fuselage 2, the drawing figures stipulate an attachment that is at least partly located at the side shells 3e. However, the location of the attachment, i. e. the mounting of the landing boxes 10a, 10b to the fuselage 2 as such is irrelevant and only depends on a predetermined configuration and construction of the landing boxes 10a, 10b, i. e. their box shells 10c with the inboard and outboard shell sections 16a, 16b. Consequently, any attachment, i. e. mounting location other than the described one(s) are also contemplated as being part of the present invention. Furthermore, also combinations of the above described configurations are contemplated. For instance, one of the landing boxes 10a, 10b can be attached by means of a screwed joint, while the other one is attached by means of a pin-in-lug joint. Likewise, the screwed and pin-in-lug joints are only described by way of example and not for limiting the invention accordingly. Instead, any suitable quick release fasteners can be used. Moreover, the landing boxes 10a, 10b can be provided with differently structured internal configurations within their internal volumes 10l, dependent on the aircraft equipment 9 that should be carried therewith, and so on.

REFERENCE LIST

[0091] 1 aircraft [0092] 1a multi-blade main rotor [0093] 1b, 1c, 1d, 1e rotor blades [0094] 1f rotor head [0095] 1g aircraft width [0096] 2 fuselage [0097] 2a fuselage underside [0098] 3a cockpit [0099] 3b cabin [0100] 3c fuselage lower shell [0101] 3d tail boom [0102] 3e fuselage side shell [0103] 3f floor level [0104] 4 counter-torque device [0105] 5 fin [0106] 6 horizontal tail [0107] 7 cabin door [0108] 8a roll axis [0109] 8b yaw axis [0110] 8c pitch axis [0111] 9 aircraft equipment [0112] 9a emergency floatation devices [0113] 9b fuel tanks [0114] 10 non-retractable skid-type landing gear [0115] 10a, 10b landing boxes [0116] 10c box shells [0117] 10d boarding steps [0118] 10e landing box access openings [0119] 10f landing box interconnection regions [0120] 10g landing box basis [0121] 10h landing box root width [0122] 10i landing box root length [0123] 10j landing box interface perimeter [0124] 10k skid-type landing base members [0125] 10l landing box internal volume [0126] 11 fuselage main attachment points [0127] 12 landing box main attachment access panels [0128] 12a landing box main ribs [0129] 13 aircraft main frames [0130] 14 main frame distance [0131] 15 screwed joint region [0132] 16a inboard shell section [0133] 16b outboard shell section [0134] 17 pin-in-lug joint region [0135] 18 massive structural support member