One target of actual development activities for helicopter drives is the substitution of the conventional swash plate actuation based on hydraulic actuators by electro-mechanical actuators. In comparison to hydraulic actuators the jam of the electro-mechanical actuators has to be considered by a jam tolerant system design.

A possible solution is a redundant system configuration with two identical actuators at the activating positions. In case of a jam the failed actuator has to be disconnected from the drive in very short time by a fast activating actuator. In regard to the requirements no state-of-the art disconnect device is applicable.

The development of the disconnect device covered two different principles:

• reversible system, preferred electro-mechanical
• “single-shot” system, preferred pyrotechnical

Therefore, the project work was carried out by 4 cooperation partners:

• The Institute of Engineering Design and Industrial Design of the University of Stuttgart (IKTD) has research experience in and expert knowledge on the development of fast operating connect/disconnect devices.
• The Italian company Umbra (Umbra) is a highly competent manufacturer and supplier of components for the aerospace industry like ballscrews, actuators and EMA drives.
• The German company PyroGlobe is a highly competent manufacturer and supplier of pyrotechnical components and will participate on the “single-shot” system.
• The Swiss company phi Engineering has experience in methodical product development and will participate on a “single-shot” system beside pyrotechnics.

During investigations performed by the IKTD a wide range of possible connect/disconnect principles were reviewed and concept studies were carried out in this context. This represented a promising basis for a continuative research work and a successful development may be expected. The experience of the industrial partners ensured the realisation of the prototype considering the aerospace requirements.