The Boeing Company

Arlene McKeeman Brown

Keith Daniel Humfeld

Kari L Stromsland

Donald K Dabelstein

Joe Heeter

Grant J Erickson

Robert Steinle

Daniel James Kovach

John A Ward

Diane L Heidlebaugh

David W Kwolek

Andrew Michael Robb

Winson Taam

Edge seals for composite structure fuel tanks are disclosed herein. One disclosed apparatus includes a seal covering an exposed edge of a carbon fiber reinforced composite fuel tank, where the seal comprises a layer of dielectric material to insulate carbon fibers at the exposed edge from fuel in the tank.

Edge seals for composite structure fuel tanks

A method is provided that includes setting up a composite material structure under test (SUT) between a transmit coil and a receive coil. The transmit coil is driven with a RF signal over a plurality of frequencies, thereby causing the transmit coil to produce a magnetic field that by magnetic coupling through the SUT induces a voltage in the receive coil. The voltage in the receive coil is measured, and from the voltage, a measurement of attenuation of the RF signal caused by the SUT between the transmit coil and receive coil is produced. And an effective conductivity of the SUT is calculated from the measurement of attenuation.

Magnetic coupling for electrical conductivity assessment

The cut laminate edges of aircraft fuel tanks formed of carbon fiber reinforced polymers are sealed to prevent the exposure of carbon fibers to combustible fuel. The edge seal is produced from a prepreg form using a thermosetting resin matched to the characteristics of the resin used in the laminate. The prepreg form can be applied to the cut laminate edges either before or after the laminate is cured. The edge seal acts as a dielectric layer that both electrically insulates the cut laminate edges from the fuel and mechanically contains energetic particles produced at the edges due to lightning strikes or other sources of electrical charges.

Disclosed in this application is a novel method and apparatus for reducing electrical resistance of a carbon-reinforced plastic structure to thereby reduce damage due to lightning strikes or precipitation static. This apparatus includes a galvanically compatible conductive interface layer positioned between a nonconductive substrate and a conductive outer surface. The interface layer is electrically conductive to transmit electrical current from the outer surface to the substrate.

Aircraft structural assembly with electromagnetic protection

A method of forming an exterior surface protective structure () for an aircraft () includes uniting a loaded surfacer () having a carrier () to a hybrid prepreg substrate (). The prepreg substrate () includes a carbon fabric () with an integral conductive component () having conductivity with in a metal conductivity range and is united to a base substrate (). The loaded surfacer () and the prepreg substrate () are cured, which includes interfacially adhering matter between the loaded surfacer () and the prepreg substrate (). A protective fabric system () for an exterior () of an aircraft () includes the base substrate (). The hybrid prepreg substrate () is coupled to the base substrate (). The loaded surfacer () with the carrier () is interfacially adhered to the prepreg substrate ().

Environmentally stable hybrid fabric system for exterior protection of an aircraft

A device senses a static charge resulting from the impingement of particles on a surface, such as an aircraft's outer skin. The device includes a sensor adapted to be installed on the surface and a corona guard for guarding against corona discharge from the sensor.

Method and device for measuring static charge

A precipitation static sensor includes a bottom flexible dielectric layer (e.g., a layer of urethane tape) configured to be attached to a wing or other external surface of an aircraft, a flexible conductive layer (e.g., a layer of aluminum tape) formed over a portion of the first flexible dielectric layer, and a conductor (such as a twisted-pair wire) coupled to the flexible conductive layer. A top flexible dielectric layer is formed over a portion of the bottom dielectric layer and a portion of the flexible conductive layer, thus forming an exposed detector region. In accordance with a further embodiment, multiple such precipitation static sensors are used and coupled to a meter device (e.g., a picoammeter), which may also be coupled to a data acquisition and display for providing a visual indication of the charge accumulated by the precipitation static sensors.

Growing community of inventors

Normandy Park, WA, United States of America

Arlene McKeeman Brown