Abstract: Each of a pair of axially spaced turbine disks (12,14) has a plurality of blade retention fingers (20) at the periphery. Each blade has a pair of chevrons (64,66), one engaging a contiguous chevron (70) on a corresponding disk finger. The interacting chevron surfaces are located on the center plane (74) of a corresponding disk. Each finger is shaped to have a linear locus (75) of neutral axis (77) from the body of the disk to the chevron location. Each blade has a hollow platform structure (24), structural members (86,88,92,94) associated with a chevron (70), an airfoil extension (63) extending through the platform (28). High temperature cooling air (34) is directed into the blades (32,26,22) while being baffled away (42) from the turbine disks (12,14). Low temperature cooling air (48) bathes the live disks.

Abstract: A helicopter (10) is roll vibration resistant having cantilever spring (40) supported masses (42) located at extreme outboard locations (30). The spring portion (40) extends substantially horizontally and is rigidly secured to rigid structure (28). This vibration absorber (34) is tuned to the forced frequency established by the normal rotor (14) RPM times the number of rotor blades (16).

Abstract: A silicone rubber vacuum bag for use in composite article manufacture is reusably sealed to a mold, without mechanical clamping means. The mold-mating portion of the bag is primed with a silicone rubber adhesive, which is cured thereto, and a layer of semiadhesive sealer is applied between the primed mold-mating portion of the bag and the mold.