LIGHTNING PROTECTION ARRANGEMENT FOR AN ELECTRONIC UNIT

• US 20110259999A1
• Filed: 01/28/2011
• Published: 10/27/2011
• Est. Priority Date: 06/03/2009
• Status: Active Grant

• Current Assignee: Airbus Operations GmbH (Airbus SE)
• Original Assignee: Airbus France, Airbus Operations GmbH (Airbus SE)
• Inventors: Frontzek, Thomas, Therond, Frederic
• Granted Patent: US 8,746,611 B2
• Time in Patent Office: Days
• US Class Current: 244/1.A
• CPC Class Codes: H02G 13/00 Installations of lightning conductors; Fastening thereof to supporting structure

Abstract

Lightning protection arrangement for diverting a current, caused by a lightning strike, from an electronic unit which is fitted to an aerodynamic fairing of an aircraft. The device comprises an electrically conductive mounting plate which is arranged on an outer side of a CFRP sandwich panel of the aerodynamic fairing. Furthermore, the device has an electrically conductive rear plate which is arranged on an inner side of the CFRP sandwich panel of the aerodynamic fairing and is connected electrically to the mounting plate. In this respect, a first group of attachment means provided for the electronic unit connects the electrical unit electrically to the rear plate. An electric current generated during a lightning strike is diverted with low resistance from the electrical unit via the rear plate and the mounting plate onto the fuselage of the aircraft.

Claims

1. A lightning protection arrangement for an aircraft for protecting an electronic unit from lightning, which arrangement is capable, during a lightning strike, of diverting a lightning current onto an electrically conductive retaining structure of the fuselage of the aircraft, wherein the electronic unit is attached to an aerodynamic fairing outside the aircraft, the lightning protection arrangement comprising:

a) an electrically conductive mounting plate which is arranged on an outer side of a CFRP sandwich panel of the aerodynamic fairing;

b) an electrically conductive rear plate which is arranged on an inner side of the CFRP sandwich panel of the aerodynamic fairing and is connected in an electrically conductive manner to the mounting plate;

c) electrically conductive and detachable attachment means which is provided to attach the electronic unit to the body, and by which an electrically conducting connection is realised between the electronic unit and the mounting and rear plates arranged on the CFRP sandwich panel, such that during a lightning strike, a low-resistance current path is provided for the lightning current from the electronic unit via the mounting plate and the rear plate, from which current path the lightning current is diverted onto the electrically conductive retaining structure of the lightning protection arrangement which is connected to the mounting plate via further electrically conductive and detachable attachment means.

2. The lightning protection arrangement according to claim 1, wherein the electronic unit is arranged in the centre of the mounting plate, an anticorrosive sealing layer being placed on the mounting plate and on which the mounting plate is positioned.

3. The lightning protection arrangement according to claim 1, wherein the CFRP sandwich panel has at least one upper CFRP sheet which consists of carbon fibre-reinforced plastics material, a honeycomb-structured layer and at least one lower CFRP sheet which consists of carbon fibre-reinforced plastics material.

4. The lightning protection arrangement according to claim 3, wherein a metallic wire mesh or a metal foil is provided on the upper CFRP sheet of the CFRP panel to protect the CFRP panel against the effects of a lightning strike.

5. The lightning protection arrangement according to claim 4, wherein the wire mesh consists of a metal alloy, preferably of a bronze wire mesh.

6. The lightning protection arrangement according to claim 4, wherein the mounting plate consists of a metal which has a low potential difference compared to the material of the wire mesh in the electrochemical series and has a low weight.

7. The lightning protection arrangement according to claim 1, wherein the mounting plate and the rear plate consist of titanium.

8. Lightning protection arrangement according to claim 1, wherein to reduce weight, the rear plate is configured annularly.

9. The lightning protection arrangement according to claim 1, wherein the outer periphery of the rear plate is connected in an electrically conducting manner to the mounting plate via electrical and conductive attachment means.

10. The lightning protection arrangement according to claim 9, wherein the periphery of the mounting plate is connected in an electrically conducting manner to the electrically conductive retaining structure via electrically conductive attachment means, the lightning current flowing via the electrically conductive plates into the retaining structure and being able to be diverted from there into the remaining fuselage region of the aircraft.

11. The lightning protection arrangement according to claim 1, wherein the electronic unit is embodied by an antenna, a sensor element, a signal light or by an illumination unit.

12. The lightning protection arrangement according to claim 1, wherein the transition resistance for diverting the current onto the aircraft fuselage is less than 5 mΩ

.

13. The lightning protection arrangement according to claim 10, wherein a guide path for an overvoltage which is generated during a lightning strike and is diverted onto the electrically conductive retaining structure runs from the electronic unit via a first group of attachment means to the rear plate and from there via a second group of attachment means to the mounting plate and from there via a third group of attachment means to the retaining structure.

14. The lightning protection arrangement according to claim 13, wherein the groups of attachment means are realised by metallic screws, preferably in each case at least by four screws, having an electrically conductive surface protection.

15. The lightning protection arrangement according to claim 13, wherein the groups of attachment means are reinforced by bolts.

16. The lightning protection arrangement according to claim 1, wherein the electrically conductive retaining structure is metallic.

17. The lightning protection arrangement according to claim 10, wherein the electrically conductive retaining structure is a substructure of a safety region of an aircraft structure which is metallic.

18. The lightning protection arrangement according to claim 1, wherein the aerodynamic fairing is an integrated component of an aircraft structure, preferably of the aircraft fuselage.

19. The lightning protection arrangement according to claim 5, wherein the wire mesh consists of a copper alloy.

20. An aerodynamic fairing for an aircraft with a lightning protection arrangement according to claim 1.

21. An aircraft with an aerodynamic fairing according to claim 20.