Aspects of the technology relate to a propeller blade assembly that is used in lateral propulsion systems for lighter-than-air high altitude platforms designed to operate, e.g., in the stratosphere. During operation, the propeller of the assembly is pointed along a specified heading and rotates at a selected velocity (e.g., hundreds or thousands of revolutions per minute). Power is supplied to the propeller as needed during lateral propulsion to move the platform along a particular trajectory or to remain on station over a given geographic location. In certain circumstances, the propeller may become damaged. This can include one or more blades breaking or shattering, which can result in failure of the propeller and potentially the entire LTA platform. The technology provides blades that are sufficiently flexible to avoid breakage or shattering due to debris impact or envelope entanglement, or otherwise shed a load. This can avoid catastrophic failure during stratospheric operation.

The present embodiment relates to a composite fibre structure (100) and a method (200) of manufacturing the composite fibre structure (200). The composite fibre structure (100) includes a core (102) and an outer layer (108) enclosing the core (102). The core (102) further includes at least one of a permanent core (104) and a temporary core (106). The permanent core (104) is 3-D printed along with the temporary core (106) to form the core structure (102). The permanent core (104) and the temporary core (106) are placed alternatively along the section, extending throughout the length of the composite fibre structure (100), or the permanent core (104) and temporary core (102) can be alternate along the length of the composite fibre structure (100). The layer (108), made of a reinforcement material, wraps the core (102) to form the composite fibre structure (100).

A fan blade comprising a blade body spanning from a blade root to a blade tip in a longitudinal direction and a fluid passageway formed within the blade body and extending from the blade root to the blade tip. The blade body spanning from a leading edge to a trailing edge in a lateral direction. The fluid passageway allowing fluid to flow out of the blade.

A fan blade comprising a blade body spanning from a blade root to a blade tip in a longitudinal direction and a fluid passageway formed within the blade body and extending from the blade root to the blade tip. The blade body spanning from a leading edge to a trailing edge in a lateral direction. The fluid passageway allowing fluid to flow out of the blade.

A propeller blade assembly includes a spar extending along a propeller blade axis and an outer sleeve surrounding the spar portion at a root end of the rotor blade assembly. The spar is adhesively bonded to the outer sleeve at an interface portion. A spar maximum diameter along the interface portion is larger than an outer sleeve minimum diameter along the interface portion. A method of assembling a propeller blade includes installing an outer sleeve over a spar at a root end of the spar, the spar a not fully cured composite component, and urging the spar into compressive conformance with the outer sleeve at an interface portion of the propeller blade assembly. A spar maximum diameter along the interface portion is larger than an outer sleeve minimum diameter along the interface portion. The spar is cured thereby adhesively bonding the spar to the outer sleeve at the interface portion.

A propeller blade assembly includes a spar extending along a propeller blade axis and an outer sleeve surrounding the spar portion at a root end of the rotor blade assembly. The spar is adhesively bonded to the outer sleeve at an interface portion. A spar maximum diameter along the interface portion is larger than an outer sleeve minimum diameter along the interface portion. A method of assembling a propeller blade includes installing an outer sleeve over a spar at a root end of the spar, the spar a not fully cured composite component, and urging the spar into compressive conformance with the outer sleeve at an interface portion of the propeller blade assembly. A spar maximum diameter along the interface portion is larger than an outer sleeve minimum diameter along the interface portion. The spar is cured thereby adhesively bonding the spar to the outer sleeve at the interface portion.

A propeller blade comprises a fibre reinforced blade structure spar having a blade retention section formed at one end thereof, and at least one metallic formation spray deposited onto said blade retention section.

A propeller blade comprises a fibre reinforced blade structure spar having a blade retention section formed at one end thereof, and at least one metallic formation spray deposited onto said blade retention section.

An aerofoil component is formed of continuous fibre-reinforced polymer composite created by curing laid up pre-preg layers extending in radial and chordal directions of the aerofoil component, and further includes a plurality of Z-pins arranged in a pattern forming a chevron on the pressure and/or suction surface of the aerofoil component, the chevron having a vertex and two arms extending at an angle from each other away from the vertex either towards the radially inner root of the aerofoil component or towards the radially outer tip of the aerofoil component.

An aerofoil component is formed of continuous fibre-reinforced polymer composite created by curing laid up pre-preg layers extending in radial and chordal directions of the aerofoil component, and further includes a plurality of Z-pins arranged in a pattern forming a chevron on the pressure and/or suction surface of the aerofoil component, the chevron having a vertex and two arms extending at an angle from each other away from the vertex either towards the radially inner root of the aerofoil component or towards the radially outer tip of the aerofoil component.