An aeroplane provided with noise-reducing means for reducing the noise level that is produced during a flight, in particular during the landing stage of the aeroplane, due to the presence of the landing gear (1) of the aeroplane, said sound-reducing means comprising deflection means for deflecting an air flow away from the landing gear (1) or at least from components thereof, characterized in that the deflection means comprise blowing means provided with a blowing element having at least one blowing nozzle (5) for creating an air screen at the front side of the landing gear (1), or at least components thereof, from said at least one blowing nozzle (5).

An airbag protection system for helicopters (10). Airbags (12,14,16) are inflated either automatically or manually, or a combination of both, prior to the helicopter striking the ground, thus avoiding or ameliorating a crash. Proximity sensors (24) detect a fast descent to trigger inflation of the airbags (12,14,16) located beneath the helicopter fuselage (10) so that they can cushion the impact with the ground. Venting of the gas from the airbags (12,14,16) is also provided to release the gas from the airbags (12,14,16) so as to prevent rebound of the helicopter (10) from the ground.

A ground engaging member comprises a circular pad, preferably a pneumatic pad, adapted to be supported from a vehicle so as to present a circular surface towards the ground, the pad being tilted so that the circular surface is angled with respect to the ground whereby a lateral portion of the circumferential region of the pad contacts the ground surface to support a vehicle on which the member is fitted for motion over the ground.

In one embodiment, moving means is incorporated to selectively move the pad between the tilted position and a horizontal position which provides an automatic braking facility. Steering can be incorporated by selectively varying the radial plane of the tilt angle of the pad.

The invention is described with reference to its use as a ground engaging member for a helicopter undercarriage; however, it can be used on any vehicle and has particular application on vehicles required to move in any direction and in a confined space.

A ground engaging member comprises a circular pad, preferably a pneumatic pad, adapted to be supported from a vehicle so as to present a circular surface towards the ground, the pad being tilted so that the circular surface is angled with respect to the ground whereby a lateral portion of the circumferential region of the pad contacts the ground surface to support a vehicle on which the member is fitted for motion over the ground.

In one embodiment, moving means is incorporated to selectively move the pad between the tilted position and a horizontal position which provides an automatic braking facility. Steering can be incorporated by selectively varying the radial plane of the tilt angle of the pad.

The invention is described with reference to its use as a ground engaging member for a helicopter undercarriage; however, it can be used on any vehicle and has particular application on vehicles required to move in any direction and in a confined space.

An impact protection apparatus (100, 200, 300) is provided, comprising a gas container (110, 210, 310) configured to hold compressed gas and an inflatable member (130, 230, 330) configured to be inflated by the gas and function as an airbag of a movable object, such as an aerial vehicle (400, 500). A valve (120, 220, 320) controls flow of gas from the container (110, 210, 310) to the inflatable member (130, 230, 330) in response to a signal from a valve controller (140, 240, 340). The valve (120, 220, 320) and valve controller (140, 240, 340) are powered by an independent power source (250, 350) than one or more other systems of the movable object. A safety mechanism (360) may also be provided that, unless deactivated, prevents inflation of the inflatable member (130, 230, 330).

The invention relates to an apparatus (10,14) for recovering the kinetic energy released during landing of an aircraft after contact with the ground, for ground and/or flight operation comprising at least one energy converter (10) for conversion of the kinetic energy into another energy form, where the energy converter is located in the area of the nose landing gear and/or in the area of the main landing gear of the aircraft. According to the invention, at least one energy storage system is provided for receiving and releasing at least a part of the converted kinetic energy.

An aircraft landing gear assembly comprising an impact protection boot (17) mounted to a landing gear component, the impact protection boot comprising: a resilient inner impact energy absorption layer (20) which engages the component (10); and an outer protective layer (22) which substantially covers the impact energy absorption layer, wherein the inner layer is more compressible than the outer layer. The boot has first and second ends which are tied to each other by a connector which exerts oppositely directed forces on the first and second ends respectively, the forces being directed around the circumference of the boot so as to tighten the boot against the landing gear component.