Abstract:
A system, an apparatus, and a method for an aerospace vehicle braking system for decelerating an aerospace vehicle on a landing surface. An arm is provided having a first portion connected to the aerospace vehicle and a second portion generally distal to the first portion. The second portion of the arm includes an engagement portion configured to engage the landing surface. The arm is movable between a first position, wherein the engagement portion is substantially disengaged from the landing surface, and a second position, wherein the engagement portion engages the landing surface with a force sufficient to significantly decelerate the aerospace vehicle. The engagement portion is configured to pivot with respect to the arm in response to the direction of travel of the aerospace vehicle upon the landing surface. An actuator is connected to the arm to selectively move the arm between the first position and the second position.

Description:
TECHNOLOGICAL FIELD 
     The present disclosure relates generally to a system and method for an emergency landing braking of an aerospace vehicle, and in particular, to an auxiliary or supplemental braking system for use in connection with a primary braking system in low traction landing conditions. 
     BACKGROUND 
     On occasion, an airplane, or some other aerospace vehicle, i.e., a vehicle capable of flight both within and outside the sensible atmosphere, may experience emergency landing situations, such as low traction conditions when a primary braking system on the airplane&#39;s main landing gear may be ineffective and/or in situations where the airplane&#39;s overrunning the end of the runway is unavoidable. These conditions may occur when landing long on the runway or landing strip with insufficient run out to accommodate normal braking procedures, or less than optimal brake capacity is realized. In these instances, the crew and aircraft may face a catastrophic situation without additional braking capacity. 
     Additional braking capacity may be provided, if the aircraft is so-equipped, by the use of thrust reversers. However, thrust reversers may have drawbacks in that they may be relatively expensive to provide on an aircraft and may also add an undesirable amount of weight to the aircraft. Additionally, thrust reversers can be relatively expensive and labor-intensive to maintain in operation. 
     Alternatives to thrust reversers exist to provide additional braking to an aircraft. For example, antiskid brake control systems and parachutes may be used for braking. 
     While antiskid braking and parachute systems may serve as effective solutions, they can be limited at times to within a relatively tight range of operational conditions. Additionally, anti-skid systems can become problematic in low friction landing situations. 
     BRIEF SUMMARY 
     Accordingly, it would be desirable to have a system, apparatus, and method that take into account at least some of the issues discussed above, as well as other potential issues. 
     Example embodiments of the present disclosure are generally directed to a system, an apparatus, and a method for an aerospace vehicle braking system for decelerating an aerospace vehicle on a landing surface, including an arm having a first portion connected to the aerospace vehicle and a second portion generally distal to the first portion. The second portion of the arm includes an engagement portion configured to engage the landing surface. The arm is movable between a first position, where the engagement portion is substantially disengaged from the landing surface, and a second position, where the engagement portion engages the landing surface with a force sufficient to significantly decelerate the aerospace vehicle. An actuator is connected to the arm to selectively move the arm between the first position and the second position. 
     In another example embodiment, landing gear is connected to the aerospace vehicle, and the arm is connected to the landing gear for pivoting or other type of movement, such as rectilinear, translatory, rotational, and/or curvilinear movement, with respect thereto between the first position and the second position. 
     In another example embodiment, the engagement portion is configured to physically damage the landing surface upon the arm being in the second position. 
     In another example embodiment, a braking device is connected to the second portion of the arm and is configured to pivot with respect to the arm in response to the direction of travel of the aerospace vehicle upon the landing surface. At least one engagement member, such as a spike, extends downwardly from the second component that engages the landing surface upon the arm being in the second position. 
     In still another example embodiment, a braking device is connected to the second portion of the arm and configured to pivot with respect to the arm in response to the direction of travel of the aerospace vehicle upon the landing surface, and another example embodiment provides that the braking device has an upturned leading surface with respect to the direction of travel of the aerospace vehicle upon the landing surface. 
     Yet another example embodiment provides a first component connected to the second portion of the arm and configured to pivot about a first axis with respect to the arm. A second component is connected to the first component and is configured to pivot with respect to the first component about a second axis generally perpendicular to the first axis in response to the direction of travel of the aerospace vehicle upon the landing surface, and at least one engagement member, such as a spike, extends downwardly from the second component and engages the landing surface upon the arm being in the engaged position. 
     Another example embodiment includes at least one debris deflector component connected to the arm that generally deflects away from the landing gear debris which may arise upon the engagement portion engaging the landing surface with a force sufficient to significantly decelerate the aerospace vehicle. 
     Still another example embodiment includes tires connected to the landing gear and at least one debris deflector component connected to the arm that generally deflects away from the tires. 
     Yet another example embodiment includes the engagement portion of the arm having at least one downwardly extending claw-shaped portion that engages the landing surface upon the arm being in the second position, and one example embodiment includes at least three spaced-apart downwardly extending claw-shaped portions that each engages the landing surface upon the arm being in the second position. 
     Another example embodiment provides at least one sensor that monitors the force exerted by the engagement portion against the landing surface, and at least one controller may be connected to the sensor and to the actuator that allows for the force exerted by the engagement portion against the landing surface to be selectively controlled. A further example embodiment includes at least one controller connected to the sensor and to the actuator that automatically applies in a predetermined manner the force to be exerted by the engagement portion against the landing surface. 
     An example embodiment may also include a landing gear system for an aerospace vehicle, the landing gear system comprising a force bearing portion connected to the aerospace vehicle that at least partially supports the aerospace vehicle. An arm is provided having a first portion connected to the force bearing portion and a second portion generally distal to the first portion. The second portion of the arm includes an engagement portion configured to forcefully engage the landing surface, and the arm is movable between a first position, wherein the engagement portion is substantially disengaged from the landing surface, and a second position, wherein the engagement portion engages the landing surface with a force sufficient to significantly decelerate the aerospace vehicle. An actuator is connected to the arm to selectively move the arm between the first position and the second position. 
     Another example embodiment of the landing gear system includes a braking device connected to the second portion of the arm and configured to pivot with respect to the arm in response to the direction of travel of the aerospace vehicle upon the landing surface and at least one engagement member, such as one or more spikes, extending downwardly from the second component that engages the landing surface upon the arm being in the position. A further example may include a braking device connected to the second portion of the arm and configured to pivot with respect to the arm in response to the direction of travel of the aerospace vehicle upon the landing surface. Additionally, at least one debris deflector device may be provided that generally deflects away from the landing gear debris which may arise upon the engagement portion engaging the landing surface with a force sufficient to significantly decelerate the aerospace vehicle. 
     Another example embodiment includes an aerospace vehicle that lands on a landing surface, that has a fuselage, an airfoil connected to the fuselage, at least one power source connected to at least one of the fuselage and the airfoil, and a landing gear configuration connected to the fuselage that provides support of the aerospace vehicle on the landing surface. An arm is provided having a first portion connected to the landing gear and a second portion generally distal to the first portion, and the second portion of the arm includes an engagement portion configured to forcefully engage the landing surface. The arm is movable between a first position substantially disengaged from the landing surface and a second position wherein the engagement portion engages the landing surface with a force sufficient to significantly decelerate the aerospace vehicle. An actuator selectively moves the arm between the first position and the second position. 
     In other aspects of example embodiments, a method is provided for decelerating an aerospace vehicle on a landing surface, and includes: possessing an arm having a first portion connected to the aerospace vehicle and a second portion generally distal to the first portion, the second portion of the arm including an engagement portion configured to engage the landing surface; moving the arm being between a first position wherein the engagement portion is substantially disengaged from the landing surface to a second position wherein the engagement portion engages the landing surface; and applying a force against the landing surface with the engagement portion sufficient to significantly decelerate the aerospace vehicle. 
     An example method may also include that the applying of the force against the landing surface with the engagement portion sufficient to significantly decelerate the aerospace vehicle aerospace vehicle is accomplished using a powered actuator and/or includes monitoring the force exerted by the engagement portion against the landing surface using at least one monitor and/or using the monitor to selectively and/or automatically control the force exerted by the engagement portion against the landing surface. 
     In other aspects of example embodiments, an airplane emergency supplemental braking system and method are provided. 
     The features, functions and advantages discussed herein may be achieved independently in various example embodiments or may be combined in yet other example embodiments, the further details of which may be seen with reference to the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Having thus described example embodiments of the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1  illustrates an airplane having an airplane emergency supplemental braking system according to one example embodiment; 
         FIG. 2  illustrates an airplane emergency supplemental braking system according to one example embodiment, with the airplane emergency supplemental braking system retracted; 
         FIG. 3  illustrates the airplane emergency supplemental braking system shown in  FIG. 2  in a deployed configuration; 
         FIG. 4  illustrates a portion of the airplane emergency supplemental braking system shown in  FIG. 2 ; 
         FIG. 5  illustrates from the rear a portion of the airplane emergency supplemental braking system shown in  FIG. 2 ; 
         FIG. 6  illustrates an engagement portion of the airplane emergency supplemental braking system shown in  FIG. 2 ; 
         FIG. 7  illustrates an engagement portion of the airplane emergency supplemental braking system shown in  FIG. 2 ; 
         FIG. 8  illustrates an airplane emergency supplemental braking system according to another example embodiment; and 
         FIG. 9  illustrates the airplane emergency supplemental braking system shown in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     Some embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the disclosure are shown. Indeed, various embodiments of the disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout. 
       FIG. 1  illustrates an airplane emergency supplemental braking system, or “system,” generally  100 , installed on an aerospace vehicle, such as an airplane, generally A. Each of the main landing gear configurations, generally MLG 1  and MLG 2 , of airplane A are illustrated as having an application of a system  100 , and both depicted as being in a deployed, or engaged, configuration, as also shown in  FIG. 3 . Airplane A has a fuselage, generally F, airfoils, such as wings, generally W, connected to fuselage F, and at least one power source, such as engines, generally E, connected fuselage F and/or wings W or tail section, generally T. 
     In  FIG. 2 , system  100  is shown in a disengaged configuration and is connected to a landing gear configuration, such as MLG 1  and/or MLG 2 , which includes a shock/strut assembly, generally  102 , to which tires  104 ,  106  are each carried for rotation on a respective axle  108 ,  109 . Tires  104 ,  106  are carried on wheels  110 ,  112 , respectively, and wheels  110 ,  112  are supported on a wheel truck beam, generally  116 . Airplane landing gear MLG 1  and/or MLG 2  could also include force bearing portions other than wheels and tires, and could include skis, tracks, rollers, etc. (none shown). 
     Wheel truck beam  116  is connected to shock/strut assembly  102  via a pivot  118  which passes through a structural member, generally  120 . A torque link arrangement, generally  122 , is provided having a lower torque link  124  and an upper torque link  126 . Torque links  124 ,  126  are interconnected by a pivot  128  and are connected via a pivot  130  to a mounting bracket, generally  132 , which may be integral to the shock/strut assembly  102 . A lower pivot  134  connects lower link  124  to shock/strut assembly  102 . 
     An arm, or yoke, generally Y, is pivotally attached to shock/strut assembly  102  via pivot  118  for movement between a disengaged position, as shown in  FIG. 2 , to a deployed, or engaged, position as shown in  FIG. 3 . Actuators, generally  140 , such as a hydraulic cylinder  140   a  (which could be double or single action and which is supplied with pressurized hydraulic fluid through line  142 ) may be used move arm or yoke Y between the disengaged and engaged positions. As seen  FIGS. 4 and 5 , system  100  includes two actuators  140   a , each connected to yoke Y. Actuators  140   a  are connected at one end thereof to yoke Y and at the other end thereof to shock/strut assembly  102 . 
     An engagement portion, generally  145 , which may include a rotatable braking device, or unit, generally  146 , is connected to a distal end of an arm  144  of yoke Y and, upon system  100  being deployed, is constructed to engage a runway or landing surface upon yoke Y being in the engaged position and to also generally rotate into alignment with the direction of travel of the airplane A on such runway or landing surface. 
     Unit  146  is pivotally attached to the distal end of yoke arm  144  via a pivot  148  and includes a pivotal and/or rotary portion, which may take the form of a skid plate, generally  146   a , which includes one or more downwardly extending engagement members, which may include a finger, tooth, barb or spike, generally  150 , the tip, generally  152 , of which includes a hardened point or tip of material, such as carbide or some other hard, durable material. 
     Actuators  140   a  are each connected to yoke Y via a pivot  154 , which are each engaged in an upstanding tab  156  in yoke Y arm  144 . This pivot arrangement allows actuators  140   a  to pivot thereabout during movement of yoke Y from a disengaged position, shown in  FIG. 2 , and the engaged position as shown in  FIG. 3 . The upper end of each actuator  140   a , which includes a piston rod extending therefrom, is connected to shock/strut assembly  102  via a pivot  158 . 
     A larger fender-shaped debris deflector  160 , which could be connected to yoke arm  144  or, alternately, to another portion of the landing gear, protects and deflects debris from tire  104  when system  100  is deployed. Debris shields  162  may also be provided on yoke arm  144  to deflect debris which may be kicked up and propelled from system  100  when deployed. 
     As shown in  FIG. 4 , the primary braking system of airplane includes a brake assembly  166  at each wheel, which under normal conditions provides the braking action for airplane A. Brake assembly  166  is connected to a beam portion  168  of wheel truck beam  116 . At the other end of wheel truck beam  116  is a beam portion  170  to which one or more wheels are connected, as shown in  FIG. 1 . 
     It should be noted here that yoke Y includes a first yoke arm portion  144 A and second yoke arm portion  144 B, and yoke Y is centered about shock/strut assembly  102 , with the upper portion of each actuator  140   a  being connected to an actuator assembly  172  fixedly connected to shock/strut assembly  102 . 
     Turning now to  FIG. 6 , braking unit  146 , is shown in detail and includes a stationary, or static, component, or plate  176   a , which is pivotally connected via pivot  148  to yoke arm portion  144 . Beneath plate  176   a  is a rotatable component, or plate,  176   c  which rotates with respect to plate  176   a  during actual use of system  100 . As noted above, unit  146 , when deployed, rotates to be oriented generally in the direction of travel of airplane A, such as in the direction of the arrow A 1  shown in  FIG. 7 , which is angularly displaced from the centerline CL of yoke arm  144 . 
     Disposed between static plate  176   a  and rotatable plate  176   c  is a ball bearing arrangement, wherein ball bearings  176   b  are carried between bearing races  176   d  and  176   e . This ball bearing arrangement allows for rotatable plate  176   c  to readily rotate as needed in emergency braking situations to optimize braking performance of engagement members  150  and hardened tips  152  in the direction of travel of airplane A, and thereby maximize the deceleration effectiveness of the drag induced against forward movement of airplane A by unit  146   a . It should be noted that although a ball bearing arrangement has been shown to facilitate the relative rotation of rotatable plate  176   c  with respect to stationary, or static plate  176   a , it is to be understood that other bearing arrangements (not shown) could be used if desired. 
     A member, generally  180 , which may take the form of a sled-shaped plate having an upturned leading edge  182 , facilitates the travel of member  180 , and accordingly unit  146   a  to which it is attached, across the surface of the runway (or other landing surface) when system  100  is deployed. Additionally, member  180  provides an elongated longitudinal dimension to the combination of rotatable plate  176   c  and plate  180  to facilitate the alignment thereof with the general direction of travel of the airplane A during braking. 
     A control circuit, generally  190 , ( FIG. 2 ) is provided in system  100  and includes a sensor, generally  192 , and a computer system, or processor, generally  194 , such as a central processing unit (CPU), processor, axis-position modular (APM), etc., which is in turn connected to the hydraulic system (not shown), which provides hydraulic pressure to actuators  140 . Sensor  192 , which could be a strain gauge, proximity sensor, pressure transducer, or the like, has the capability of monitoring the downward force applied by yoke arm  144  when system  100  is deployed, and through connection with processor  194 , can output such force in a manner (visually and/or audibly, etc.) in a manner that allows the pilot and/or air crew to monitor such force during emergency procedures. Such monitoring could be done via a display in the cockpit and/or through audible annunciators. Such downward force can be modulated manually via processor  194 , i.e., selectively and/or automatically, if desired, with a predetermined downward force being selected for yoke arm  144 , with such force being automatically maintained through feedback from sensor  192  and through interaction with sensor  192 , processor  194 , and actuators  140 . 
     Referring specifically to controller  194  mentioned herein, other embodiments may provide a non-transitory computer readable medium and/or storage medium, and/or a non-transitory machine readable medium and/or storage medium, having stored thereon a machine code and/or a computer program having at least one code section executable by a machine and/or a computer, thereby causing the machine and/or computer to perform the steps as described herein with respect to dual function movement of yoke Y and/or braking unit  146 . 
     Accordingly, aspects of the presently disclosed embodiments may be realized in hardware, software, or a combination of hardware and software. The present embodiments may be realized in a centralized fashion in at least one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system  194  or other system adapted for carrying out the methods described herein may be suitable. For example, a typical combination of hardware and software may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein. 
     Aspects of the presently disclosed embodiments may also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system  194  is able to carry out these methods. “Computer program” in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form. 
     Turning now to  FIGS. 8 and 9 , another example embodiment of the present invention is illustrated. As shown in  FIG. 8 , such alternate example system, generally  200 , includes an arm  206  having one or more downwardly extending claws, generally  208 . In the embodiment shown in  FIG. 9 , three downwardly extending claws  208   a ,  208   b , and  208   c  are provided. Preferably, each such claw includes a hardened tip  210  thereon for engaging the runway and/or landing surface. Arm  206 , and accordingly, claw members  208   a ,  208   b , and  208   c  are moved between a disengaged, and engaged, or deployed, position via hydraulic actuators  140 , such as discussed above in regard to system  100 . 
     While hydraulic actuators have been discussed herein, it is to be understood that other devices could be used, such as pneumatic cylinders, motorized screw mechanisms, magnetic systems, dead-weight systems, and/or electromagnetic systems, etc., instead of or in combination with the hydraulic actuators discussed herein. 
     In operation, an airplane emergency supplemental braking system  100  as disclosed herein may be activated in a landing scenario by the pilot flying or the first officer. Upon a sufficient portion of the airplane&#39;s weight being placed on the landing gear wheels  110 ,  112  and low friction surface conditions being detected (and a determination made that the loss of, or significant damage to, the airplane is probable due to over-running the end of the runway), it may become advisable to deploy system  100 . 
     The activation controls (not shown) for system  100  could, for example, be placed on the airplane&#39;s flight deck, such as on the center aisle stand near the thrust levers, since they could be used in conjunction with thrust reversers, if the airplane is so-equipped. The controls could also be duplicated on the outboard console in situations when the pilot flying directs the first officer to manage the deployment of the system. 
     As system  100  is activated, a portion of the airplane&#39;s weight is transferred from the tires  104 ,  106  of the main landing gear to the hardened tips or teeth  152  of the engagement members  150  of system  100 , thereby causing a relatively large concentrated friction against the landing surface, or runway substrate, and in some cases, physically damaging and sacrificing the substrate if maximum force is applied against yoke arm  144  by the pilot. During this process, runway portions and debris may be lifted and propelled in a number of directions. When system  100  has been deployed, engagement members  150 , start to penetrate into the runway or other landing surface and could potentially fracture such surface. 
     By virtue of the drag created by activation of the system  100 , the required runway length should therefore be reduced, and in some cases a dramatic reduction may be possible. It is also possible that system  100  could prevent loss of the aircraft in cases of severe cross-wind conditions combined with low friction runway surface conditions. Under this potentially “side skid” condition, the system  100  could potentially prevent the airplane from unintentionally leaving the side of the runway. 
     System  100  facilitates rapid airplane deceleration as braking unit  146   a  is forced itself into a slippery runway surface after landing, and its activation is particularly suited when the airplane&#39;s primary or conventional brake system cannot provide enough traction to stop the airplane from running off the runway or from crashing against other objects. 
     The present invention thus finds application in those cases when it is better to damage a fraction of the runway pavement rather than lose or significantly damage the entire airplane and risk injury to those onboard the airplane and/or bystanders. 
     It is conceivable that the present invention or a modified embodiment of it could be used in situations other than emergencies. In primitive runway situations, or limited risk operations, it may be possible to use the system  100  without damage to the airplane, main landing gear, tires, etc. Such flights may be encountered in icy landing situations, for example, in scientific field operations in which civilians are supported by the military flying C-130 airplanes into McMurdo Station in Antarctica. 
     Many modifications and other embodiments of the disclosure set forth herein will come to mind to one skilled in the art to which these disclosure pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.