DESIGN AND FABRICATION OF AN ADVANCED LIGHT ROTOR

Future military rotorcraft must perform with even greater operational effectiveness than the current helicopter fleet if they are to meet the mission requirements for increased performance, lower vibrations, and greater reliability. New rotor systems must provide the improvements that will enable future rotorcraft to meet these requirements, and preproduction prototyping is a cost-effective method of reducing development risk. These prototypes are used to verify and aid in the development of analytical models used to design the next generation of rotorcraft. Bell Helicopter Textron has modified its successful Model 680 four-bladed, composite, bearingless rotor by incorporating new rotor blades designed and fabricated with advanced technology. This paper describes the aerodynamic design requirements and structural design practices used to create the simple blade structure, the dynamic tuning methods used to achieve low vibration, and the use of CAD to disseminate engineering and tooling information. Discussion of tooling and manufacturing approaches that yield the blades at a 33% time savings and a 40% cost savings over typical preproduction blades will be included.