The helicopter control system used to regulate the cyclic pitch change of the rotor blades.

Ball sizing, also known as ball broaching or Ballizing , is the process of forcing an oversize ball through the inside diameter of metal part. It will increase the inside diameter and greatly improve the surface texture of the part.

Short durations of reverse flow in a gas-turbine engine due to instability.

An intentionally designed weak spot within a pressurized system. The rupture disk is expected to fail before other more valuable equipment is damaged or destroyed, or before an explosive force can be created that will endanger human life.