Lightning Protection of Revolving Aircraft Turrets

Honeybee proposes a Rotary Lightning Protection System (RLPS) that combines the existing metal mesh/coating approach to lightning strike mitigation with the innovative Rotary Band Contact (RBC) concept to provide a ground path for rotating compositestructures. The RLPS design will not only protect the mechanisms that produce the required rotary motion, but will also protect any sensitive equipment within by providing a direct exterior path away from the rotating member directly to ground. Honeybeeplans to design a lightweight system compatible with nose-mounted ball turrets such as the one employed by the Airborne Laser Boeing 747-400. The proposed RLPS uses high yield strength, flexible roll rings for rotary power transfer. The roll rings mayexperience large, prolonged compressive forces without permanent deformation. Also, by avoiding the sliding contact traditionally associated with power transfer across rotating interfaces, wear is greatly reduced. As a result, particulate generation, whichmay increase the likelihood of current arcing, a serious concern near aircraft fuel tanks, and damage sensitive optical equipment, is essentially eliminated. The RLPS design offers reliable high-current transfer capabilities, minimal wear, low torqueresistance, low noise production and continuous rotation; a prime candidate for the lightning protection of aircraft rotary interfaces.