EUROCAE ED-91A PDF

This EUROCAE ED / SAE Aerospace Recommended Practice (ARP) 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. The zone location guidelines and examples are representative of in-flight lightning exposures.

PURPOSE

This ED/ARP provides information to determine aircraft lightning attachment zones. This lightning zoning ED/ARP should be used with two other documents, ED-84/ ARP5412 and ED-105/ARP5416. The relationship between the three documents is shown in FIGURE 1. These documents are used to define the aircraft lightning environment and tests required to support the aircraft lightning protection certification. Lightning zoning is one step in demonstrating that the aircraft is adequately protected from both direct and indirect effects of lightning. Lightning zoning defines the surfaces of the aircraft that are likely to experience lightning channel attachment and the aircraft structures that conduct lightning current between attachment points.

Lightning zoning should be used with the aircraft lightning hazard assessment to determine the appropriate protection for a given aircraft part or location. The criticality of the systems or structure in the zone should be considered when defining the appropriate protection for parts and structure in a particular lightning zone.