Controlling an in-flight spin-rate of a spin-stabilized guided projectile is disclosed. In various embodiments, the projectile includes a despun control portion configured for despinning relative to a projectile chassis and for directional control of the projectile. In various embodiments, controlling the in-flight spin-rate includes determining a gyroscopic stability factor for the guided projectile using the in-flight spin rate and a forward velocity of the guided projectile, determining that the gyroscopic stability factor exceeds a stability threshold, and spin-braking the guided projectile, in response to determining that the gyroscopic stability factor exceeds a threshold value, by braking rotation of the despun control portion by which the gyroscopic stability factor of the guided projectile is reduced to a second gyroscopic stability factor.

Controlling an in-flight spin-rate of a spin-stabilized guided projectile is disclosed. In various embodiments, the projectile includes a despun control portion configured for despinning relative to a projectile chassis and for directional control of the projectile. In various embodiments, controlling the in-flight spin-rate includes determining a gyroscopic stability factor for the guided projectile using the in-flight spin rate and a forward velocity of the guided projectile, determining that the gyroscopic stability factor exceeds a stability threshold, and spin-braking the guided projectile, in response to determining that the gyroscopic stability factor exceeds a threshold value, by braking rotation of the despun control portion by which the gyroscopic stability factor of the guided projectile is reduced to a second gyroscopic stability factor.

A guided projectile having a nose portion, a body portion, a tail portion, and a central axis. In various embodiments the projectile includes a control support portion and a collar assembly pivotally mounted to the control support portion. In various embodiments the collar assembly includes a collar having an exterior sidewall with a plurality of fixed aerodynamic surfaces thereon for spinning the collar and a plurality of variable sweep wings for directional control of the projectile. In various embodiments the plurality of variable sweep wings each have a first end coupled to a wing actuator configured to rotate a second end portion between and including a first position, where the wings are oriented generally parallel to the central axis of the projectile to a second position, where the lengthwise wing axis of the plurality of wings are oriented generally perpendicular to the central axis of the projectile.

A guided projectile having a nose portion, a body portion, a tail portion, and a central axis. In various embodiments the projectile includes a control support portion and a collar assembly pivotally mounted to the control support portion. In various embodiments the collar assembly includes a collar having an exterior sidewall with a plurality of fixed aerodynamic surfaces thereon for spinning the collar and a plurality of variable sweep wings for directional control of the projectile. In various embodiments the plurality of variable sweep wings each have a first end coupled to a wing actuator configured to rotate a second end portion between and including a first position, where the wings are oriented generally parallel to the central axis of the projectile to a second position, where the lengthwise wing axis of the plurality of wings are oriented generally perpendicular to the central axis of the projectile.

The invention relates to a system for emergency starting a turbine engine, characterised in that it comprises a flyer for driving the turbine engine, said flyer comprising a drum (2) rigidly connected to a rotary shaft (3), the axes of symmetry (LL) of the drum (2) and of the shaft being coincident, the flyer further comprising at least one exhaust nozzle (4) for ejecting gas, which is positioned on the periphery of the drum (2) and oriented substantially tangentially to the rotation about said axis (LL), and a pyrotechnic gas generation device which is installed in the flyer and feeds said at least one exhaust nozzle (4), said emergency start system further comprising a support in which the shaft of the flyer rotates, and a volute for recovering the gases, which radially surrounds the flyer and is rigidly connected to said support.