WO2021130037A1

WO2021130037A1 - Aircraft cargo bay door assembly

Info

Publication number: WO2021130037A1
Application number: PCT/EP2020/085881
Authority: WO
Inventors: Alexander PANKRATOV; Alexey KARACHAROV; Vladimir Golovko; Alexander E. KOZLOV; Sergey KICHIN; Alexander SAVOSTIN; Alexander KHOMMIK; Sergey Anikin
Original assignee: Airbus Sas
Priority date: 2019-12-25
Filing date: 2020-12-13
Publication date: 2021-07-01
Also published as: RU2019143934A

Abstract

An aircraft cargo bay door assembly, comprising: a cargo bay door configured to pivotably connect to an airframe; and a door support mechanism including: an extendable strut having a first strut end and a second strut end, the first strut end pivotably connected to the cargo bay door; and a connector arm having a first arm end connected to the second strut end and a second arm end; wherein the connector arm is configured to pivotably connect to the airframe at the second arm end about a pivot axis extending through a longitudinal axis of the extendable strut between the first and second strut ends.

Description

AIRCRAFT CARGO BAY DOOR ASSEMBLY

FIELD OF THE INVENTION

[0001] The present invention relates to an aircraft cargo bay door assembly, and an aircraft comprising an airframe and the cargo bay door assembly.

BACKGROUND OF THE INVENTION

[0002] An aircraft will typically have multiple cargo bays, also known as cargo holds. These cargo bays are used to securely store luggage, or cargo, during a flight. Each cargo bay is accessed through a door located on the outside of the aircraft. The door is typically hinged at the top and swings inwards into the cargo bay, although in some aircraft one or more cargo bay door swing outwardly to open.

[0003] In order to compensate for the weight of the cargo door, such that an operator doesn't have to apply any substantive force to open the door and that the door remains open in whatever position it is moved to, cargo bay doors typically use a torsion spring mechanism. This offsets the weight of the door, such that the door is effectively weightless on its hinge.

[0004] Torsion springs are expensive, difficult to install, and slow to move. The mechanisms are also complex and heavy due to the large number of parts required in the torsion spring mechanisms.

[0005] An alternative to a torsion spring is an extendable strut, such as a gas spring. However, struts are limited in the amount of extension they can achieve, with this limit of extensibility generally being a percentage of the initial, non-extended, length of the extendable strut. Gas springs are also only able to support certain magnitudes of load at each degree of extension, with that load carrying ability varying with the length of extension of the strut.

[0006] It is important that the strut is able to extend and allow the cargo bay door to fully open, as well as support the weight of the door at all open positions.

[0007] However, space constraints in an aircraft place restrictions on the usable size of strut in a cargo bay door assembly, and the kinematics of the mechanism. As a result, even if a larger strut can be used, it may still not be able to support the door in all open positions.

SUMMARY OF THE INVENTION

[0008] A first aspect of the invention provides a aircraft cargo bay door assembly, comprising: a cargo bay door configured to pivotably connect to an airframe; and a door support mechanism including: an extendable strut having a first strut end and a second strut end, the second strut end pivotably connected to the cargo bay door; and a connector arm having a first arm end connected to the first strut end and a second arm end; wherein the connector arm is configured to pivotably connect to the airframe at the second arm end about a pivot axis extending through a longitudinal axis of the extendable strut between the first and second strut ends.

[0009] A further aspect of the invention provides an aircraft comprising an airframe and the aircraft cargo bay door assembly.

[0010] The cargo bay door may be configured to open inwardly. I.e. inwards relative to the aircraft.

[0011] A further aspect of the invention provides an aircraft assembly, comprising: a cargo bay door pivotably connected to an airframe; and a door support mechanism including: an extendable strut having a first strut end and a second strut end, the second strut end pivotably connected to the cargo bay door; and a connector arm at the first strut end pivotably connected with the airframe at a pivot axis; wherein the first and second strut ends are each spaced from and pivot about the pivot axis.

[0012] A further aspect of the invention provides an aircraft assembly, comprising a movable aircraft component pivotably connected to a fixed aircraft component; and a support mechanism for supporting at least a portion of the weight of the movable aircraft component including: an extendable strut having a first strut end and a second strut end, the second strut end pivotably connected to the movable aircraft component; and a connector arm at the first strut end pivotably connected with the fixed aircraft component at a pivot axis; wherein the first and second strut ends are each spaced from and pivot about the pivot axis. [0013] The connector arm is configured to pivotably connect to the airframe or other fixed aircraft component at the second arm end about a pivot axis extending through the longitudinal axis of the extendable strut between the first and second strut ends. This means the extendable strut overlaps the connector when viewed in a plane parallel to a longitudinal axis of the extendable strut. In other words, the connector is parallel and adjacent to the strut, and remains parallel to the strut throughout movement/extension of the strut.

[0014] By providing a connector between the extendable strut and the airframe, specifically a connector that is overlapped by the extendable strut when viewed in a plane parallel to a longitudinal axis of the extendable strut, a larger strut may be used without adversely affecting the kinematics of the cargo bay door assembly. As long as the connection points of the extendable strut at the airframe (indirectly through the connector) and at the door remain the same, the central axis of rotation of the extendable strut is the same no matter what size of strut is used. All that would change is the size of the connector. As a result, the first and second strut ends are each spaced from and pivot about the pivot axis of the extendable strut, with the pivot axis between the ends of the strut.

[0015] If the connector was not used, and instead an extendable strut were attached directly to the airframe, the only way in which a larger strut could be used is by moving the attachment position of the strut to the airframe and thereby altering the kinematics. Due to the standard range of the spring lengths that are typically available, and lack of the space available in aircraft assemblies, a lot of complex and expansive mechanisms typically need to be used, for example torsion mechanisms or complex lever combinations. In contrast, the current invention allows standard sized gas springs to be used, without compromising on the kinematics of the mechanism.

[0016] The door support mechanism may be configured to fully support the weight of the cargo bay door throughout the range of motion of the cargo bay door.

[0017] The cargo bay door may be configured to move to a closed position as the extendable strut extends and to move to an open position as the extendable strut contracts. The cargo bay door may be configured to open as the extendable strut extends and close as the extendable strut contracts.

[0018] The first strut end may be pivotably connected to the first arm end.

[0019] The connector arm may be a bracket. The bracket may be L-shaped. The bracket may be U-shaped.

[0020] The cargo bay door may be configured to rotate about a hinge axis. The cargo bay door may be configured to rotate at least 45 degrees about the hinge axis. The cargo bay door may be configured to rotate at least 60 degrees about the hinge axis.

[0021] The pivot axis may be parallel and spaced from the hinge axis.

[0022] The extendable strut may be configured to fully support the weight of the cargo bay door between the open position and the closed position.

[0023] The cargo bay door assembly may comprise a mount mounting the second strut end with the cargo bay door.

[0024] The cargo bay door may include a door body and a hinge arm extending from the door body, the hinge arm having a free end configured to pivotally connected to the airframe. A hinge axis of the hinge arm may be offset from a door frame of the airframe.

[0025] With this arrangement, the rotational centre of the door is offset from the door frame, such that the extendable strut may be provided with an increased moment arm.

[0026] The second strut end may be pivotably connected to the hinge arm of the cargo bay door.

[0027] The extendable strut and the hinge arm may move in the same plane. In other words, the longitudinal axis of the strut lies on a geometric plane, and the plane may cross a point at which the cargo bay door is configured to pivotably connect to the airframe (e.g. a hinge).

[0028] With this arrangement, the moment developed by an extendable strut that is otherwise offset from the pivotal connection to the airframe can be reduced.

[0029] Alternatively, the plane may be offset from any point at which the cargo bay door is configured to pivotably connect to the airframe [0030] The extendable stmt may be a linear actuator.

[0031] The extendable stmt may be a gas spring.

[0032] The cargo bay door assembly may be attached to a bulk head, also known as a frame, of a fuselage of the aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

[0034] Figure 1 shows a fixed wing aircraft;

[0035] Figure 2 shows a part of a bulk cargo bay of the aircraft including a cargo bay door assembly according to a first example;

[0036] Figure 3 a shows a side view of the cargo bay door assembly in a closed position;

[0037] Figure 3b shows a side view of the cargo bay door assembly in a partially open position;

[0038] Figure 3 c shows a side view of the cargo bay door assembly in an open position;

[0039] Figure 4 shows a side view of a cargo bay door assembly that does not form part of the present invention;

[0040] Figures 5a and 5b show perspective views of a cargo bay door assembly according to a second example;

[0041] Figure 6a shows a side view of the cargo bay door assembly in a closed position;

[0042] Figure 6b shows a side view of the cargo bay door assembly in a partially open position;

[0043] Figure 6c shows a side view of the cargo bay door assembly in an open position;

DETAILED DESCRIPTION OF EMBODIMENT(S) [0044] Figure 1 illustrates a typical fixed wing aircraft 1 having a port wing 2 and starboard wing 3 carrying wing mounted engines 9, the wings 2, 3 extending from a fuselage 4. The fuselage has a nose 5 and a tail 6 with horizontal and vertical stabiliser surfaces 7, 8 near the tail 6. The aircraft 1 is a typical jet passenger transport aircraft but the invention is applicable to a wide variety of fixed wing aircraft types, including commercial, military, passenger, cargo, jet, propeller, general aviation, etc. with any number of engines attached to the wings or fuselage.

[0045] The fuselage 4 is constructed of a skin 11. The skin 11 is supported by an airframe 12 that includes a number of bulkheads 13, also known as frames, spaced along the longitudinal axis of the fuselage and a number of longerons 14 extending along the longitudinal axis of the fuselage (See Figure 2). The airframe 12 may also include other structural members, such as stringer and stiffeners (not shown).

[0046] The aircraft 1 includes front and rear cargo bays (not shown), as well as a bulk cargo compartment aft of the rear cargo bay that is accessed through a cargo bay door that includes a door body 20 and two hinge arms 21a, 21b, as shown in Figure 1. The bulk cargo compartment is typically filled through the cargo bay door 20 with non- containerised cargo (e.g. luggage that is not in a container).

[0047] The cargo bay door is part of a cargo bay door assembly 16, as shown in Figure 2, and opens about a cargo bay door hinge 24. The cargo bay door slots inside a cargo bay door frame 18 formed in the fuselage 4.

[0048] As previously mentioned, the cargo bay door includes a door body 20 and two hinge arms 21a, 21b. The hinge arms 21a, 21b are spaced apart and rigidly connected at a first end 22 to the door body 20. Each hinge arm 21a, 21b is pivotally connected at a second end 23 between an adjacent pairs of bulkheads 13a, 13b about a pivot axis 25, such that rotation of the hinge arms 21a, 21b about the pivot axis 25 causes the door body 20 to also rotate about the pivot axis 25.

[0049] The cargo bay door is thereby able to open and close relative to the cargo bay door frame 18. [0050] The moment arm of the hinge arms 21a, 21b is increased by offsetting the pivot axis 25 of the hinge arms 21a, 21b from the door frame 18 of the cargo bay door. That is, the pivot axis of the hinge arms 21a, 21b is not located on the door frame 18, and is instead offset and above the door frame 18. This helps to reduce the force needed to move the door about the pivot axis.

[0051] The rotation of the cargo bay door about the pivot axis 25 is aided by an extendable strut 30 attached to each hinge arm 21a, 21b. The extendable strut shown in Figure 2 is a gas strut, however the extendable strut may be any suitable linear actuator that is able to support and/or develop a load. Each gas spring 30 is part of a door support mechanism that supports the door 20 and allows it to be opened and closed with minimal external force.

[0052] Figure 2 shows two door support mechanisms, each connected to a respective hinge arm 21. The door support mechanisms act to compensate the weight of the door 20

[0053] The door support mechanism will now be described in relation to Figures 3a to 3c, in which only one door support mechanisms of the cargo bay door assembly 16 is shown in order to increase clarity.

[0054] Each door support mechanism of the cargo bay door assembly 16 includes a connector arm 40 and a mount 50 connected at either end of the gas spring 30.

[0055] Figure 3a shows a side view (i.e. looking substantially in the longitudinal direction of the aircraft) of the cargo bay door assembly 16 in the closed position. In the closed position, the door body 20 is enveloped within the cargo bay door frame 18 of the fuselage 4.

[0056] The cargo bay door assembly 16 includes a connector arm 40 fixedly connected at a first end 41 to a first end 31 of the respective gas spring 30. A second end 42 of the connector arm 40 is rotatably connected to the airframe 12, specifically in this case an adjacent bulkhead 13 although other features of the airframe 12 may be used to anchor the connection to the aircraft 1. The connection to the airframe 42 is shown as a dotted line, although it will be clear that the connection 42 is behind the gas spring 30 and is only shown to improve comprehension. [0057] Each door support mechanism of the cargo bay door assembly 16 further includes a mount 50. The mount 50 is fixedly connected at a first end 51 to the hinge arm 21 of the cargo bay door and rotatably connected at a second end 52 to the second end of the gas spring 30.

[0058] The connector arm 40 is arranged such that the central axis of rotation 33 of the gas spring 30 is coincident with the axis of the second end 42 of the connector arm 40. The central axis of rotation (and the connection point 42 on the airframe 12) is therefore offset from the first end 31 of the gas strut 30, the offset distance determined by the length of the connector arm 40. The central axis of rotation 33 of the gas spring 30 is positioned to provide the maximum mechanical advantage achievable given the space constraints of the bulk cargo compartment.

[0059] As shown in Figure 3a, the connector arm 40 is arranged such that the gas spring 30 passes and overlaps the connection point 42 to the airframe 12 (i.e. the connection of second end 42 of the connector arm 40 to the airframe 12). In other words, the gas spring 30 extends parallel and adjacent to the extent of the connector arm 40, the extent of the connector arm 40 being defined as a straight line between the first end 41 and the second end 42. This is true in all door positions.

[0060] For example, Figure 3b shows the cargo bay door in a partially open position in which it can be seen that the gas spring 30 passes and overlaps the connection point to the airframe 12.

[0061] Similarly, this is also shown in Figure 3c, which shows the door in the fully open position.

[0062] In Figure 3b, the cargo bay door is opened by approximately 30 degrees relative to the closed position shown in Figure 3a.

[0063] In Figure 3c, the cargo bay door is opened by approximately 60 degrees relative to the closed position shown in Figure 3a, and opened by approximately 30 degrees relative to the partially open position shown in Figure 3b. [0064] The cargo bay door is opened by unlocking the cargo bay door (lock not shown) and pushing the door body 20 inwards. In doing so, the gas spring 30 is kinematically arranged to support the weight of the cargo bay door and ensure minimal force is required to move the cargo bay door.

[0065] As the cargo bay door rotates about its pivot axis 25, the gas strut 30 tracks the movement of the cargo bay door and provides support throughout its movement between the fully closed (Figure 3a) and fully open (Figure 3c) positions.

[0066] In an alternative example show in Figure 4, which does not form part of the present invention and is described only for the purposes of explanation, the gas spring 30 extends directly between the airframe 12 and the door body 20, i.e. there is no connector arm 40 between the first end 31 of the gas spring 30 and the airframe 12.

[0067] In some instances the configuration shown in Figure 4 may be sufficient to allow the door to open sufficiently for a given requirement, and possibly support the cargo bay door at all open positions. However, if a larger gas spring 30 is required then the configuration in Figure 4 requires one or both of the connection points 31, 32 of the gas spring 30 to be moved, thereby changing the rotational centre of the gas spring in relation to the door hinge 24. This change in kinematics can mean the larger gas spring 30 is less effective in its new configuration, potentially undoing any improvement that a larger gas spring 30 would otherwise provide. For example, the gas spring 30 may no longer be able to provide the force required to support the cargo bay door in all required open positions, or its position may be shifted sufficiently so that it is not able to extend the required amount to fully open the door.

[0068] In contrast, by providing a connector arm 40 between the gas spring 30 and the airframe 12 (as shown in Figures 3a to 3c), specifically a connector arm 40 that is overlapped by the gas spring 30 when viewed in a plane parallel to a longitudinal axis of the gas spring 30, a larger gas spring 30 than the linear distance between the connection point 42 to the airframe 12 and the connection point to the cargo bay door can be used whilst maintaining the rotational centre of the gas spring 30. As a result, it is possible to modify the assembly 16 by adding a larger gas spring 30 without adversely affecting the kinematics of the cargo bay door assembly 16. [0069] The connector arm 40 between the gas spring 30 and the airframe 12 therefore allows larger gas springs to be used, whilst maintaining the best position of the rotational centre of the gas spring 30.

[0070] The gas springs 30 shown in Figures 2 and 3 are each offset from their respective hinge arms 21a, 21b, such that the gas spring 30 is forward (relative to the longitudinal axis of the aircraft 1) of the respective hinge arm 21 to which it is attached. The result of this lateral installation is that a moment is developed by the action of the gas spring 30 relative to the pivot axis 25 of the hinge arms 21a, 21b.

[0071] Any adverse effects of this moment can be at least partially addressed by positioning the gas springs 30. For example, by positioning one gas spring 30 forward of one of two hinge arms 21a, 21b and positioning the other gas spring 30 aft of the other of the two hinge arms 21a, 21b, such that the moments counteract each other. As a result, the gas springs 30 and hinge arms 21a, 21b define a symmetry plane between them.

[0072] Alternatively, the moment produced by the gas spring 30 may be reduced by minimising the offset.

[0073] Figures 5a and 5b show a perspective view of an example of a cargo bay door assembly 16 (door body 20 not shown) in which the offset between the hinge arm 21 and gas spring 30 is minimised.

[0074] The door support mechanism operates in substantially the same manner as the door support mechanism shown in relation to Figures 2 to 3, in particular with the connector arm 40 arranged such that the central axis of rotation 33 of the gas spring 30 is coincident with the axis of the second end 42 of the connector arm 40. The door support mechanism shown in Figures 5a to 5b differs in that the offset between the pivot axis 25 of the hinge arm 21 and the central axis of rotation 33 of the gas spring 30 is minimised in the longitudinal direction of the aircraft, i.e. there is no longitudinal offset between the two components. [0075] To accommodate the overlap between the hinge arm 21 and gas spring 30, the gas spring 30 extends between two adjacent lateral portions 26a, 26b of the hinge arm 21 and through an opening 27 in the hinge arm 21. As a result, the hinge arm 21 and gas spring 30 both extend along a common 2D-plane.

[0076] Due to the overlap between the hinge arm 21 and gas spring 30, any moment that may otherwise develop due to an offset of the gas spring 30 is minimised.

[0077] The reconfiguration of the hinge arm 21 to include adjacent lateral portions 26a, 26b results in this particular hinge arm 21 being heavier than those shown in relation to Figures 3a to 3c, however the overall weight of the cargo bay assembly 16 is less than those shown in relation to Figures 3a to 3c.

[0078] Figure 6a shows a side view (i.e. looking substantially in the longitudinal direction of the aircraft) of the cargo bay door assembly 16 in the closed position, in which the connector arm 40, and part of the gas spring 30 are shown as dotted lines to indicate they are hidden behind the rib 13 and/or hinge arm 21.

[0079] Figure 6b shows the cargo bay door in a partially open position, whilst Figure 6c shows the door in a fully open position. It is clear, when comparing the relative configurations of Figures 3a-3c and Figures 6a-6c that the kinematics of the two cargo bay assemblies are substantially the same when viewed from the side, along the longitudinal axis of the aircraft 1.

[0080] It will be clear to the skilled person that the examples described above may be adjusted in various ways. For example, the connector arm 40 is fixedly connected at a first end 41 to a first end 31 of the respective gas spring 30, wherein fixedly refers to the two respective parts being fixed relative to each other. Alternatively, the connector arm 40 may be rotatably connected at the first end 41 to the first end 31 of the respective gas spring 30.

[0081] The cargo bay door assembly 16 is described in relation to the use of a gas spring 30, wherein the gas spring 30 is able to support the weight of the cargo bay door. The cargo bay door is therefore able to be manually opened using minimal external force, and supports itself using the gas spring 30 in any open position. [0082] Alternatively, a different type of linear actuator may be used that is able to actively generate a load, such that the cargo bay door can be actively opened without any external force being applied.

[0083] The cargo bay door assembly 16 is described in relation to its use in opening the cargo bay door of a bulk cargo compartment within the fuselage 4 of an aircraft 1, however it will be readily understood that the assembly 16 is suitable to assist in the opening of any cargo bay door.

[0084] The cargo bay door assembly 16 is shown in three positions: closed (Figures 3a and 6a), partially open (Figures 3b and 6b), and fully open (Figures 3c and 6c). The open configurations shown in Figures 3c and 6c are each opened by approximately 60 degrees with respect to the closed position, however it will be clear to the skilled person that the fully open configuration may provide a cargo bay door that opens more or less than 60 degrees. For example, the cargo bay door 20 may open no more than 45 degrees, 50 degrees, 60 degrees, 75 degrees, or 90 degrees. The cargo bay door 20 may open at least 45 degrees, 50 degrees, 60 degrees, 75 degrees, or 90 degrees.

[0085] Typically, the cargo bay door 20 will be fully supported at all positions, although the door may only be supported throughout a portion of its movement. For example, the door may be supported by the linear actuator during its first 45 degrees of travel, but then the linear actuator may compensate for a portion of the weight of the door above 45 degrees.

[0086] The extendable strut, specifically identified as a gas spring 30 in some examples, supports the door. The extendable strut may support all of the weight of the door, such that the door feels essentially weightless, or may support only a portion of the weight of the door. The cargo bay door assembly may include a lock to fix the position of the door in any required position. [0087] The support mechanism is suitable for supporting the weight of other aircraft components. For example, in alternative examples, the support mechanism supports at least a portion of the weight of a passenger door, an overwing exit door, and an emergency exit door. The support mechanism may support at least a portion of the weight of any suitable aircraft component, such as a control surface. For example an air brake.

[0088] Where the word 'or' appears this is to be construed to mean 'and/or' such that items referred to are not necessarily mutually exclusive and may be used in any appropriate combination.

[0089] Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. An aircraft cargo bay door assembly, comprising: a cargo bay door configured to pivotably connect to an airframe; and a door support mechanism including: an extendable strut having a first strut end and a second strut end, the second strut end pivotably connected to the cargo bay door; and a connector arm having a first arm end connected to the first strut end and a second arm end; wherein the connector arm is configured to pivotably connect to the airframe at the second arm end about a pivot axis extending through a longitudinal axis of the extendable strut between the first and second strut ends.

2. The aircraft cargo bay door assembly according to claim 1, wherein the door support mechanism is configured to fully support the weight of the cargo bay door throughout the range of motion of the cargo bay door.

3. The aircraft cargo bay door assembly according to claim 1 or 2, wherein the cargo bay door is configured to move to a closed position as the extendable strut extends and to move to an open position as the extendable strut contracts.

4. The aircraft cargo bay door assembly according to any preceding claim, wherein the first strut end is pivotably connected to the first arm end.

5. The aircraft cargo bay assembly of any preceding claim, wherein the connector arm is a bracket and, optionally, the bracket is one of L-shaped and U-shaped.

6. The aircraft cargo bay door assembly according to any preceding claim, wherein the cargo bay door is configured to rotate about a hinge axis, and the door is configured to rotate at least 45 degrees about the hinge axis, and more preferably at least 60 degrees about the hinge axis.

7. The aircraft cargo bay door assembly according to claim 6, wherein the pivot axis is parallel and spaced from the hinge axis.

8. A cargo bay door assembly according to any preceding claim, comprising a mount mounting the second strut end with the cargo bay door.

9. The aircraft cargo bay door assembly according to any preceding claim, wherein the cargo bay door includes a door body and a hinge arm extending from the door body, the hinge arm having a free end configured to pivotally connect to the airframe.

10. The aircraft cargo bay door assembly according to claim 9, wherein the second strut end is pivotably connected to the hinge arm of the cargo bay door.

11. The aircraft cargo bay door assembly according to claim 9 or 10, wherein the extendable strut and the hinge arm move in the same plane.

12. The aircraft cargo bay door assembly according to any preceding claim, wherein the extendable strut is a linear actuator.

13. The aircraft cargo bay door assembly according to any preceding claim, wherein the extendable strut is a gas spring.

14. An aircraft comprising an airframe and the aircraft cargo bay door assembly of any preceding claim.

15. The aircraft according to claim 14, wherein the cargo bay door is configured to open inwardly.

16. The aircraft according to claim 14 or 15, wherein the cargo bay door assembly is attached to a bulkhead of a fuselage of the aircraft.

17. An aircraft assembly, comprising: a cargo bay door pivotably connected to an airframe; and a door support mechanism including: an extendable strut having a first strut end and a second strut end, the second strut end pivotably connected to the cargo bay door; and a connector arm at the first strut end pivotably connected with the airframe at a pivot axis; wherein the first and second strut ends are each spaced from and pivot about the pivot axis.

18. An aircraft assembly, comprising: a movable aircraft component pivotably connected to a fixed aircraft component; and a support mechanism for supporting at least a portion of the weight of the movable aircraft component including: an extendable strut having a first strut end and a second strut end, the second strut end pivotably connected to the movable aircraft component; and a connector arm at the first strut end pivotably connected with the fixed aircraft component at a pivot axis; wherein the first and second strut ends are each spaced from and pivot about the pivot axis.