Navigational Air (NAVAID) : Any visual or electronic device located on the ground or on shipboard which provides point-to-point guidance information and/or partial or complete position data to aircraft in flight.
Ilan Kelman (ed.), Vulnerability and Resilience Definitions and References, Version 2, 2007. http://www.islandvulnerability.org/docs/vulnres.pd f, (Vulnr and Resilience - Brit) {524}