Abstract: A reaction-jet helicopter having an air compressor and a power source operable to power the compressor. The air compressor is in fluid communication with a cavity in a rotor blade of the reaction-jet helicopter. The rotor blade has one or more openings for the expulsion of compressed air from the cavity thereby resulting in rotation of the rotor blade. The reaction jet helicopter further has an arrangement for manipulating airflow between the compressor and the one or more openings. This results in reduced losses of energy as the airflow travels from the compressor to the one or more openings.

Abstract: A compressed gas ejection assembly for a rotating wing aircraft blade comprising a compressed gas passage adapted to allow a substantially constant mass flow through the compressed gas ejection assembly across at least a portion of the width of the compressed gas ejection assembly.

Abstract: A reaction-jet helicopter having an air compressor and a power source operable to power the compressor. The air compressor is in fluid communication with a cavity in a rotor blade of the reaction-jet helicopter. The rotor blade has one or more openings for the expulsion of compressed air from the cavity thereby resulting in rotation of the rotor blade. The reaction jet helicopter further has an arrangement for manipulating airflow between the compressor and the one or more openings. This results in reduced losses of energy as the airflow travels from the compressor to the one or more openings.

Abstract: A compressed gas ejection assembly 10 for a rotating wing aircraft blade 2 comprises a compressed gas passage 114 adapted to allow a substantially constant mass flow through the compressed gas ejection assembly 10 across at least a portion of the width of the compressed gas ejection assembly 10.

Abstract: A safety and arming device for a munition is operable to arm and initiate a munition dependent on determining separation from a munition platform, determining detection of free fall of the device for a first time period following separation, initiating a roll manoeuvre of the munition and determining detection of the execution of the roll manoeuvre within a second time period, and generating a munition firing signal, dependent on detection of all of separation, free fall, and the roll manoeuvre.

Abstract: A method of making a mould for moulding polymeric composites comprises embedding at least one layer 30 of a fibre reinforced polymer and a plurality of heating elements 24 within a spreadable ceramic material 28. The curing temperature of the ceramic material is less than the melting point of the polymer. The ceramic material is cured at a temperature less than the melting point of the polymer to yield a solid ceramic body, and the ceramic body is then heated at a temperature above the melting point of the polymer so that the latter is fused with the fibres to strengthen the mould. The mould is suitable for use for the manufacture of polymeric composites. A process for moulding polymeric composites using the mould is also described.

Abstract: A process for the manufacture of a composite article is described wherein the process comprises the steps of (i) providing on a tool (22) a fibrous material (14) having associated therewith in at least one region thereof an in-situ polymerisable non-fibrous form of a thermoplastic material; (ii) applying heat and a vacuum to said material; and additionally (iii) drawing into the fibrous material, from a source external to the tool, additional thermoplastic pre-polymer material. The process described is particularly useful for the manufacture of a large composite structure such as thermoplastic composite wind turbine blade, for example.