An airflow modification patch 14 for reducing aeroacoustic noise generated by an aircraft assembly. The patch has a substrate 14a and a plurality of airflow disruption elements 14b.

An aircraft fairing includes a fairing body having an exterior fairing wall and at least one wheel bin. The at least one wheel bin has a side wall extending from an opening in the exterior fairing wall to an end wall. The side wall and the end wall define a cavity of the at least one wheel bin in fluid communication with the opening in the exterior fairing wall. An acoustic resonator is mounted to an outer surface of the side wall of the at least one wheel bin and is in fluid communication with the cavity. The acoustic resonator has a resonant frequency substantially similar to a cavity modal frequency of the at least one wheel bin at an aircraft flight condition.

A system for use in an aircraft or other system in an ambient airflow includes a body defining a cavity having an opening exposed to ambient airflow, with a cavity interface defined by body structure surrounding the opening. The cavity interface includes a cavity floor opposite the cavity opening, a leading edge facing away from the ambient airflow, a trailing edge facing the airflow, and a rear wall extending between the trailing edge and the cavity floor. A panel of sound-absorbing material is attached to and covers substantially all of the surface area of the rear wall of the cavity, and minimizes emanation of a predetermined range of audible sound frequencies from the cavity. The system may include an elongated serrated element connected to body and extending along the leading edge and arranged flush with the leading edge.

Pressure oscillations or acoustic loads over an open type cavity having a front face an upper edge of which constitutes a leading edge and having a rear face an upper edge of which constitutes a trailing edge are reduced by applying curvature to the rear face so as to present a convex curved surface internal to the cavity. In one embodiment, a cross-section through a longitudinal axis of the convex curved surface describes part of an ellipse.

An exposed main landing gear cavity in a bottom wall of an aircraft fuselage may include a main landing gear cavity outer ring recessed within the fuselage and having an inner surface encircling the main landing gear cavity, first baffle extending inward from the outer ring inner surface at an aft and inboard position on the inner surface, and a second baffle extending inward from the outer ring inner surface at an aft and outboard position on the outer ring inner surface. The main landing gear cavity may further include an aft fairing disposed proximate the outer ring bottom edge of the outer ring and connected to the fuselage at an aft side of the main landing gear cavity. An aft fairing top surface may have curvature causing the top surface to extend downward away from the outer ring as the top surface extends inward away from the outer ring.

A stretchable mesh material extends across the opening of a cavity of the landing gear of an aircraft when the landing gear is in the deployed position. The mesh material alters the flow of air across the opening of the landing gear cavity and significantly reduces the amount of noise produced by the wheel well at low-to-mid frequencies.

The present disclosure refers to a method for operating a landing gear system, preferably in a tricycle configuration, wherein main landing gear (MLG) and the nose landing gear (NLG) are operable from a retracted position where they are housed respectively inside landing gear bays, to a fully extended position where they are extended for landing the aircraft. According to the disclosure, the extension of the nose landing gear (NLG) is delayed in time with respect to the extension of the main landing gear (MLG), and the nose landing gear (NLG) is kept retracted during a major part of the time that the main landing gear doors (MLGD) are extended. In this manner, vibrations on the main landing gear doors are reduced and incidents caused by fatigue are also reduced, which in turn implies that the maintenance cost of the aircraft is greatly reduced.

A low stall or minimum control speed aircraft comprising a fuselage that has vertically flat sides; wings with high a lift airfoil profile of constant chord section set at zero degree planform sweep, twin booms having inner vertically flat surfaces, twin vertical stabilizers, a flying horizontal stabilizer; preferably twin engines having propellers and wherein each engine preferably has a thrust-line that is inclined nose-up to a maximum of +8 degrees, and is parallel to the wing chord underneath wing mounts and landing gear doors that provide surfaces for channeling propeller wash in a rearward direction; all working in concert so that the airplane has an extremely low stall speed and minimum control speed. The engines may be diesel, hydrogen fuel cell, electric fuel cell, diesel-electric, gas turbine or combinations thereof. The propellers may be counter-rotating.

A cavity system is provided. The cavity system (100-600) comprises: a cavity (2) and a spoiler (104-604); and the spoiler (104-604) having a front surface and a rear surface. The spoiler (104-604) is positioned in proximity to a leading edge (14) of the cavity (2), the leading edge (14) being relative to an actual or intended flow direction (3) of a fluid over the cavity (2). The spoiler (104-604) is arranged with its longitudinal axis perpendicular or at an oblique angle to the actual or intended flow direction (3) such that the front surface faces towards the flow direction (3). A first region of the spoiler (104-604) extends further toward the leading edge than a second region of the spoiler (104-604).

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.