EUROCAE ED-91 PDF

This document defines lightning strike zones and provides guidelines for locating them on particular aircraft, together with examples. The zone definitions and location guidelines described herein are applicable to Parts 23, 25, 27, and 29 aircraft and rotorcraft. The zone location guidelines and examples are representative of in¬ flight lightning exposures. Aircraft may also experience lightning strikes while parked on the ground, In which case some lightning strike zones may differ from those applicable in flight.

PURPOSE

This document is one of a set of three covering the whole spectrum of aircraft interaction with lightning. The purpose of this document is to provide information to determine the lightning attachment zones which is referred to as Lightning Zoning. The two other documents provide advisory material on the aircraft lightning environment (Ref. 1.4.1), and aircraft lightning testing {Ref. 1.4.2). The relationship between the three documents is shown in Figure 1-1. This set of documents may be used to define the aircraft lightning threat and tests required to support the aircraft lightning protection certification.

Lightning zoning is a functional step in demonstrating that the aircraft is adequately protected from both direct and indirect effects of lightning. The purpose of lightning zoning is to determine the surfaces of the aircraft which are likely to experience lightning channel attachment and the structures which may experience lightning current conduction between pairs of entry/exit points.

Zoning should be used with the aircraft hazard assessment to determine the appropriate protection for a given aircraft part or location. To determine the appropriate protection for parts and structure in a particular lightning zone, the criticality of the systems or structure in the zone should be considered.