Landing gear noise abatement devices

A noise abatement system for an aircraft landing gear is provided. The system may have a retention member and a covering member. In this regard, the system may be configured to block the airflow through a structural void to abate noise. Moreover, the system may be shaped to diminish aerodynamic drag.

FIELD

The present disclosure relates to landing gear systems and, more specifically, to a noise abating device for use with an articulating landing gear.

BACKGROUND

Aircraft noise generated during approach is a growing concern at airports. Noise restrictions have a significant influence on the availability of flight times and allowed aircraft types. Due to significant advances in engine technology, airframe noise is becoming relatively more significant as a source of noise. Typical articulating or trailing arm type landing gear systems incorporate a forward main post and a trailing arm attached via a joint. A shock strut may extend between these two members so that the trailing arm may articulate upward or downward. Typically, the joint is a forked clevis at the lower end of the main post, mating to the trailing arm. During deployment, prior to landing and/or after takeoff, air rushes through an open space within the forked clevis, causing noise and harsh tones at frequencies audible to the human ear. Thus, there remains a need for landing gear noise abatement systems.

SUMMARY

A noise abatement system may comprise a retention member and a covering member.

In various embodiments, a retention member may comprise a post adapted to interface with the landing gear by friction fitting or a fastening apparatus adapted to interface with the landing gear by fasteners.

In various embodiments, a covering member may comprise a void covering portion which extends substantially across a void in the landing gear, and optionally, a landing gear covering portion which extends beyond one or more of the edges of the void.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration and their best mode. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the inventions, 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 disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. 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.

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. As used herein, phrases such as “make contact with,” “coupled to,” “touch,” “interface with” and “engage” may be used interchangeably.

With reference toFIGS. 1 and 2, typical articulating or trailing arm type landing gear systems incorporate a forward main post102and a trailing arm104attached via a joint. A shock strut106may extend between these two members so that the trailing arm104may articulate upward or downward (e.g., along the y axis). Typically the joint is a forked clevis at the lower end of the main post102, mating to the trailing arm104. A void108is bounded in the X-axis by the forked clevis at the lower end of the main post102and in the Y-axis by the main post102and the trailing arm104. The void extends in the Z-axis through the landing gear system so that during deployment of the landing gear, air may rush through the void, causing noise and harsh tones at frequencies audible to the human ear.

With reference toFIG. 3, in various embodiments, a noise abatement system300may comprise a retention member304and a covering member302. Retention member304interfaces with a forward main post102of a landing gear. Covering member302attaches to or is integral with retention member304. Covering member302is configured to block air from flowing through a void in the landing gear.

With continuing reference toFIG. 3, and momentary reference toFIG. 4, in various embodiments, retention member304of a noise abatement system300may interface with forward main post102by friction fitting into a cavity in forward main post102. The term cavity as used herein may refer to a portion of the interface between a structure that hounds void108and that engages retention member304. Alternatively, retention member304may interface with forward main post102via snap-fitting, via detents, via fasteners, or via any other configuration or mechanism suitable for holding, maintaining, or otherwise coupling or retaining retention member304in mechanical communication with forward main post102.

In various embodiments, covering member302may extend substantially over void108in the landing gear and/or may occupy a cross-sectional area bounded in the X-axis by the forked clevis at the lower end of the main post102and in the Y-axis by the main post102and the trailing arm104. However, covering member302may be positioned in any configuration adapted to ameliorate aerodynamic noise by diverting air flow from the void108. In various embodiments, covering member302extends in a plane substantially normal to the direction of air flow. In various embodiments, a covering member comprises a void covering portion which extends substantially over a void in the landing gear or may occupy a cross-sectional area bounded in the X-axis by the forked clevis at the lower end of the main post102and in the Y-axis by the main post102and the trailing arm104. In various exemplary embodiments of noise abatement systems, a covering member includes a void covering portion and other covering portions, which extend beyond one or more of the edges of the void, for example, forward main post covering portions, trailing arm covering portions, side flange covering portions, and fastening side flange covering portions as illustrated with respect to the various exemplary embodiments of noise abatement systems ofFIG. 3-FIG. 16.

With reference toFIG. 5, noise abatement system500is shown. A retention member comprises a post501adapted to interface with forward main post102via friction fitting. In various embodiments, post501slides into a cavity in forward main post102and frictionally engages at least one surface of the cavity. In various embodiments, post501may engage a cavity comprising the entire void, or a portion of a void, for example, two sides of the void, or three sides of the void, or four sides of the void, or all sides of the void, or any configuration or number of surfaces of the void suitable for holding, maintaining, or otherwise coupling or retaining the post501in mechanical communication with forward main post102.

With reference toFIG. 6, in various embodiments of noise abatement system600, a retention member comprises a tab602adapted to interface with forward main post102via insertion of a fastener through an aperture in tab602. In various embodiments, noise abatement system600may have one tab602. Alternatively, a noise abatement system600may have two tabs, three tabs602, four tabs602, or any number of tabs suitable for holding, maintaining, or otherwise coupling or retaining retention member304in mechanical communication with forward main post102. In one embodiment, tab602may be arranged on a left or right side of noise abatement system600. Alternatively, tab602may be arranged on an upper or lower side of noise abatement system600, or may be arranged on multiple sides of the noise abatement system600or may comprise any arrangement of tabs suitable for holding, maintaining, or otherwise coupling or retaining retention member304in mechanical communication with forward main post102.

With renewed reference toFIG. 5, a covering member may comprise a void covering portion502and/or may comprise other additional portions, or no additional portions. As illustrated with respect to various additional embodiments discussed herein, the covering member may extend beyond one or more of the edges of the void108such that void covering portion502of the covering member only comprises a portion of the covering member. In various embodiments, the void covering portion502comprises a flat piece of material having a curved flange section504wherein the void covering portion502is shaped to substantially fit a profile of a void108in the landing gear.

With reference toFIGS. 7 and 12, noise abatement system700may have a retention member comprising a tab706and a covering member with a void covering portion702. For example, with reference toFIG. 7, in various embodiments of a noise abatement system700, a covering member comprises both a void covering portion702and a forward main post covering portion704which extends upward away from the forked clevis portion of forward main post102to externally shield a portion of the forward main post102. Moreover, the retention member may alternatively comprise a post, or any other configuration suitable for holding, maintaining, or otherwise coupling or retaining noise abatement system700in mechanical communication with the landing gear.

Alternatively, referring now toFIGS. 8 and 13, noise abatement system800may have a retention member comprising a post806and a covering member with a void covering portion802and a trailing arm covering portion804which extends downwardly away from the forked clevis portion of forward main post102to externally shield a portion of the trailing arm104. Moreover, the retention member may alternatively comprise a tab, or any other configuration suitable for holding, maintaining, or otherwise coupling or retaining noise abatement system800in mechanical communication with the landing gear.

In various embodiments, with reference toFIGS. 9 and 14, noise abatement system900may have a retention member comprising a post906and a covering member with a void covering portion902and side flange covering portions904. Side flange covering portions904may extend laterally to shield a portion of the landing gear, for example, the forward main post102, or the joint between the forward main post102and the trailing arm104. In various embodiments, side flange covering portions904may have cutouts to permit noise abatement system900to be installed without impinging on or otherwise interfering with other landing gear structures, for example, fittings such as grease zerks. Alternatively, the retention member may comprise a tab, or any other configuration suitable for holding, maintaining, or otherwise coupling or retaining noise abatement system900in mechanical communication with the landing gear.

In various embodiments, with reference toFIGS. 10 and 15, noise abatement system1000may have a covering member with a void covering portion1002and fastening side flange covering portions1004. Moreover, fastening side flange covering portions1004may also serve as a retention member. Fastening side flange covering portions1004may extend laterally to shield a portion of the landing gear, for example, the forward main post102, or the joint between the forward main post102and the trailing arm104. In various embodiments, fastening side flange covering portions1004may have cutouts to permit noise abatement system1000to be installed without impinging on or otherwise interfering with other landing gear structures, for example fittings such as grease zerks.

Furthermore, fastening slide flange portions1004may also serve as a retention member and may have a fastening apparatus1008by which noise abatement system1000may be held, maintained, or otherwise coupled or retained in mechanical communication with forward main post102. In various embodiments, fastening side flange covering portions1004are bent, for example, to follow a profile of the forward main post102, wherein a 90 degree bend causes fastening apparatus1008of at least one fastening side flange covering portion1004to be positioned generally against a face of forward main post102substantially normal to a plane of void covering portion1002.

A noise abatement system300may comprise two fastening side flange covering portions1004. Alternatively, a noise abatement system300may comprise one fastening side flange covering portion1004, or three fastening side flange covering portions1004, or four fastening side flange covering portions1004or any number or configuration of fastening side flange covering portions1004adapted to hold, maintain, or otherwise couple or retain system300in mechanical communication with forward main post102.

With reference toFIGS. 11 and 16, noise abatement system1100may have a covering member with a retention member comprising a tab1104and a void covering portion1102shaped to ameliorate aerodynamic drag, for example, by being curved. For example, the entire void covering portion1102is curved and the void covering portion1102comprises the entire covering member. Alternatively, the void covering portion1102comprises only a portion of the covering member, or still alternatively, in various embodiments, only a portion of the void covering portion1102is curved. A curve of the void covering portion1102may be a spherical cap, or may be a hemisphere. In various embodiments, the void covering portion1102may be conical in shape. In various embodiments, the void covering portion1102may comprise any shape adapted to diminish aerodynamic resistance exerted on system1102. In various embodiments, the void covering portion1102may have a chord and a camber and may approximate an for example, by conforming the profile of a portion of the landing gear to the profile of a NACA listed airfoil, or any other shape, configuration, or arrangement to ameliorate aerodynamic drag. Moreover, the retention member may alternatively comprise a post, or any other configuration suitable for holding, maintaining, or otherwise coupling or retaining noise abatement system1100in mechanical communication with the landing gear.

Now, having described various components of various exemplary noise abatement systems, a noise abatement system may be manufactured from various materials. In one exemplary embodiment, a noise abatement system may comprise plastic. Alternatively, a noise abatement system may comprise metal, such as titanium, aluminum or stainless steel, though it may alternatively comprise numerous other materials configured to provide support, such as, for example, composite, ceramic, a para-aramid fiber material such as a para-aramid fiber composite material, for example, a KEVLAR® brand material available from E. I. du Pont de Nemours and Company, ultra high molecular weight polyethylene such as an ultra-high molecular weight polyethylene composite material, for example, a DYNEEMA® brand material available from Royal DSM, an aramid fiber material such as an aramid fiber composite material, alloy, glass, binder, epoxy, polyester, acrylic, or any material or combination of materials having a desired strength, stiffness, or flexibility sufficient to maintain resiliency during use. In various embodiments, various portions of noise abatement systems as disclosed herein are made of different materials or combinations of materials, and/or may comprise coatings. For example, a retention member may be coated with a frictional material and covering member may be coated with an aerodynamic material. In various embodiments, the retention member is manufactured separately from the covering member.

In various embodiments, noise abatement systems may comprise multiple materials, or any material configuration suitable to enhance or reinforce the resiliency and/or support of the system when subjected to wear in an aircraft operating environment or to satisfy other desired electromagnetic, chemical, physical, or biological properties. Furthermore, noise abatement systems may comprise materials with grain structures or with no grain structures. Noise abatement systems may comprise materials with similar grain structures, or with differing grain structures or grain direction or with similar grain structures or grain direction or any grain structure or direction suitable for achieving desired properties in the system; for example, resiliency under aerodynamic loads and temperature changes.

In various embodiments, while the noise abatement systems described herein have been described in the context of aircraft applications; however, one will appreciate in light of the present disclosure, that the system described herein may be used in connection with various other vehicles, for example, cars, trucks, busses, trains, boats, and submersible vehicles, or any other vehicle or device, having a void through which gas or fluid may flow, creating, for instance, noise or drag.