Abstract:
A movement control strap for an off-wing evacuation system is disclosed. The strap is coupled between the ramp and slide, and engages with the edge of the wing. The strap stabilizes the evacuation system by providing a tensioning force to control movement of the ramp and slide. The strap assembly utilizes the edge of the wing as a leverage point for extra tensioning and control of the system.

Description:
BACKGROUND 
     An off-wing evacuation system is designed to have a ramp that leads to the sliding portion of the system. Typically, as an evacuee jumps onto the slide, the downward force on the slide exerts a torque on the ramp, causing a portion of the ramp to rotate away from the wing surface; as an evacuee exits the slide, the ramp may fall back to the wing surface. This motion of the ramp causes a tripping hazard for subsequent evacuees entering the ramp. High wind conditions may also destabilize the evacuation system, for example by lifting the slide away from the wing surface. 
     SUMMARY 
     According to various embodiments, disclosed is a movement controlled off-wing evacuation system and movement control strap for an aircraft including a wing, comprising a ramp, a slide extending from the ramp, and a movement control strap coupled between the ramp and the slide, the movement control strap comprising a first portion attached to the ramp at a ramp anchoring point, a second portion attached to the slide at a slide anchoring point, and a third portion between the first portion and the second portion, wherein the third portion is configured to engage with the wing of the aircraft at a wing anchoring point. 
     According to various embodiments, the ramp anchoring point is at an underside of the ramp; and the slide anchoring point is at an underside of the slide. 
     According to various embodiments, the first portion and the second portion are opposite ends of the movement control strap. 
     According to various embodiments, the ramp comprises a walking portion having a ramp leading edge forming a ramp entrance, wherein the ramp anchoring point is proximate the ramp leading edge. 
     According to various embodiments, the ramp anchoring point is centered about the ramp leading edge. 
     According to various embodiments, the ramp leading edge is configured to substantially rest upon the wing, the ramp further comprising a ramp trailing edge opposite the ramp leading edge, wherein the ramp trailing edge is configured to be suspended above the wing edge. 
     According to various embodiments, the slide comprises a lower slide edge and an upper slide edge, forming a sliding portion there between, wherein the slide anchoring point is below the upper slide edge. 
     According to various embodiments, the sliding portion is centered between a first slide rail and a second slide rail, wherein the slide anchoring point is at one of the first slide rail or the second slide rail. 
     According to various embodiments, the wing comprises a wing trailing edge, wherein the wing engagement point is at the wing trailing edge. 
     According to various embodiments, the ramp and the slide are components of a continuous inflatable unit. 
     According to various embodiments, disclosed is an off wing evacuation method for an aircraft, the aircraft including an aircraft wing, comprising: coupling a first portion of a movement control strap to an underside of an evacuation ramp; coupling a second portion of the movement control strap to an underside of an evacuation slide, wherein the evacuation ramp and the evacuation slide form a continuous inflatable unit; and engaging a third portion of the movement control strap at an edge of the aircraft wing, wherein the third portion of the movement control strap is located between the first portion and the second portion of the movement control strap. 
     According to various embodiments, evacuation ramp has a ramp leading edge forming a ramp entrance, wherein the movement control strap is coupled approximately at said ramp leading edge. According to various embodiments, the aircraft wing includes a wing trailing edge, and the off wing evacuation method further comprises engaging the third portion of the movement control strap at the wing trailing edge. According to various embodiments, the evacuation ramp includes a ramp leading edge forming a ramp entrance, further comprising: positioning the evacuation ramp upon the aircraft wing, wherein the ramp leading edge is positioned to substantially rest upon the aircraft wing; and anchoring the ramp leading edge to the aircraft wing via the movement control strap. 
     According to various embodiments, the evacuation ramp further comprises a ramp trailing edge opposite the ramp leading edge, the aircraft wing including a wing edge, further comprising positioning the ramp trailing edge to be suspended above the wing edge; and positioning the movement control strap to engage with the wing edge. 
     According to various embodiments, the slide comprises a lower slide edge and an upper slide edge, forming a sliding portion there between, the method further comprising coupling the second portion of the movement control strap below the upper slide edge. 
     According to various embodiments, the sliding portion is centered between a first slide rail of the slide and a second slide rail of the slide, the method further comprising coupling the second portion of the movement control strap to one of the first slide rail or the second slide rail. 
     According to various embodiments, the method further comprises positioning the movement control strap to engage with the wing trailing edge. 
     According to various embodiments, strap comprises loop patches for attachment. 
     According to various embodiments, the ramp comprises rails. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. The present disclosure will become more fully understood from the detailed description and the accompanying drawings wherein: 
         FIG. 1  is an illustration of an off-wing evacuation system with a movement control strap for an aircraft, according to various embodiments; 
         FIG. 2A  is a perspective view of the system of  FIG. 1 , according to various embodiments; 
         FIG. 2B  is an illustration of a movement control strap for the system of  FIG. 1 , according to various embodiments; and 
         FIG. 3  illustrates an aircraft off-wing evacuation method, according to various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     All ranges and ratio limits disclosed herein may be combined. It is to be understood that unless specifically stated otherwise, references to “a,” “an,” and/or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. 
     The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration and its best mode, and not of limitation. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that logical, chemical and mechanical changes may be made without departing from the spirit and scope of the invention. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Moreover, many of the functions or steps may be outsourced to or performed by one or more third parties. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. 
     In accordance with various embodiments, shown in  FIGS. 1 and 2A  show a movement controlled off-wing evacuation system  100  for an aircraft  101  comprising a ramp  102 , a slide  104  extending downwards (along the “z” axis of reference axis  111 ) and back (in the “y” or aft direction) from the ramp  102  when inflated, and a movement control strap  106  coupled between the ramp  102  and slide  104 , and in engagement with the wing  108  of aircraft  101 . Both ramp  102  and slide  104  form a continuous inflatable unit, according to various embodiments, and are shown in an inflated state in the figures. 
     According to various embodiments, ramp  102  comprises a ramp leading edge  110  forming the ramp entrance, a walking portion  107 , and may include rails  109 . According to various embodiments, walking portion  107  and ramp leading edge  110  are generally horizontal but may also be slightly angled to conform to the geometry of the wing  108 . According to various embodiments, slide  104  comprises a sliding portion  123  centered between a first slide rail  124  and a second slide rail  125 . Slide  104  may include structural support components such as transverse tube  126 , for example. 
     Wing  108  generally slopes downwards from its wing leading edge  103  to its wing trailing edge  105  (along the “y” axis of reference axis  111 ). During off-wing evacuation, the ramp leading edge  110  of ramp  102  rests on wing  108 , and the ramp trailing edge  112  of ramp  102 , or of walking portion  107 , is suspended approximately above wing trailing edge  105  of wing  108 . Evacuees exit the aircraft  101  onto wing  108 , enter and walk through the ramp  102 , and then slide down the slide  104 , according to various embodiments. 
     According to various embodiments, movement control strap  106  comprises a first portion  118 , which is located at a first end  130  of movement control strap  106 , attached to the underside  120  of ramp  102  at an anchoring point  113  (“ramp anchoring point  113 ”); and a second portion  119 , which is located at a second end  132  of movement control strap  106 , attached to the underside  122  of slide  104  at an anchoring point  115  (“slide anchoring point  115 ”). According to various embodiments, ramp anchoring point  113  is proximate ramp leading edge  110 . According to various embodiments, slide anchoring point  115  is between the lower edge  114  (or ground edge  114 ) of slide  104  and the upper edge  116  of slide  104 . According to various embodiments, slide anchoring point  115  is approximately around lower edge  114  of slide  104 . According to various embodiments, ramp anchoring point  113  may be anywhere along ramp leading edge  110 . According to various embodiments, ramp anchoring point  113  may be approximately centered along the ramp&#39;s width (along the “x” axis of reference axis  111 ). According to various embodiments, ramp anchoring point  113  may be off center. According to various embodiments, slide anchoring point  115  may be approximately centered (i.e. attached at transverse tube  126 ); or off centered with an attachment point at one of the slide&#39;s side rails  124 ,  125 , for example. According to various embodiments, both ramp anchoring point  113  and slide anchoring point  115  are off-center. According to various embodiments, one of the anchoring points  113 ,  115 , may be off centered in one direction (i.e. away from the body of the aircraft  101 ), and the other anchoring point may be off centered in the other direction (i.e. towards the body of the aircraft  101 ). This configuration may help anchor the leading edge of the ramp more closely with the wing  108 . 
     Movement control strap  106  further engages wing  108  at a point  117  (“wing engagement point  117 ”) on wing trailing edge  105  of the wing  108 , and may configured to be in contact with wing trailing edge  105 . Typically, as one evacuee jumps onto the slide  104 , the force exerted in the negative z direction on the slide  104  tends to exert a torque on the ramp  102  to urge the ramp  102  to rotate away from the wing  108  in the positive z direction and positive y direction simultaneously. However, the movement control strap  106  retains ramp  102  against wing  108  and thus tends to prevent ramp  102  from rotating with respect to wing  108 . As an evacuee exits the slide  104 , movement control strap  106  tends to retain slide  104  with respect to wing  108 , thus reducing relative motion between slide  104  and wing  108 . The engagement of movement control strap  106  against the wing  108 , provides reinforcing tension and leverage for controlling undesired movement of the ramp  102  and slide  104 , and anchoring of the ramp  102  to the wing  108 . Thus, movement control strap  106  tensions the ramp  102  towards the wing  108 . 
     According to various embodiments, movement control strap  106  may comprise a webbing, such as a nylon webbing, rope, cord, or strap. According to various embodiments, movement control strap  106  may comprise a para-aramid fiber such as that sold under the mark KEVLAR. According to various embodiments, movement control strap  106  may comprise a nylon fiber or nylon fiber blend such as those sold under the mark CORDURA. Movement control strap  106  may have a high tensile strength. According to various embodiments, movement control strap  106  comprises a tubular nylon webbing conforming to a U.S. military specification MIL-W-5625K Natural. Such webbing comprises a 420d Fill, 840d ground yarn nylon, and is about 9/16 inches (22.86 cm) wide, with tensile strength of 1500 lbs (680 Kg), and weight of 0.60 oz./linear yard (about 31 g/m). Such material webbing may have a flammability requirement to meet governmental standards, for example, in the United States, 14 CFR 25.853. Movement control strap  106  may have one or more loop patches on both first and second ends that are bonded to the ramp  102  and slide  104 . 
     According to various embodiments, movement control strap  106  is attached at either of its ends. According to various embodiments, movement control strap  106  may be attached via an attachment element such as a loop patch which may form one or both of its ends for bonding to the ramp  102  and slide  104  of the system (e.g. via adhesive). For example,  FIG. 2B  shows the movement control strap  106  comprising a first loop patch  200  which is looped around first end  130  of movement control strap  106  for bonding to the ramp  102 , and a second loop patch  202  which is looped around second end  132  for bonding to the slide  104 . According to various embodiments, off-wing evacuation system  100  may include a plurality of movement control straps  106 . According to various embodiments, off-wing evacuation system  100  comprises a slide  104  and ramp  102  including an attached movement control strap  106 , which is stowed as one unit. 
     Specific materials, arrangements, attachment sites for the movement control strap  106 , etc. may depend on the specific slide and ramp system used, including factors such as size and weight of evacuation system and/or aircraft, required operating capacity, weather conditions, etc. 
       FIG. 3  illustrates an off wing evacuation method  300 , according to various embodiments, comprising coupling a first portion of a movement control strap  302  to the underside of an evacuation ramp. The method further comprises coupling a second portion of a movement control strap  304  to the underside of an evacuation slide  304 . The method further comprises engaging a third portion of the movement control strap  306  at an edge of a wing. According to various embodiments, the ramp  102  and slide  104  form a continuous inflatable unit. According to various embodiments, the third portion of the movement control strap is located between the first portion and second portion of the movement control strap. 
     Systems and methods are provided. In the detailed description herein, references to “various embodiments”, “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. 
     Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the invention. The scope of the invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.