a. In this advisory circular (AC), the Federal Aviation Administration (FAA) provides guidance on airworthiness approval of enhanced vision system (EVS), synthetic vision system (SVS), combined vision system (CVS), and enhanced flight vision system (EFVS) equipment installation.
b. This AC provides specific system performance guidance on enhanced and synthetic vision systems and equipment. Other existing ACs address flight guidance symbology, head-up displays (HUD) and visual display characteristics (for example, AC 25-11A, Electronic Flight Deck Displays, and AC 25.1329-1B, Approval of Flight Guidance Systems). For a complete listing of related regulations and guidance, refer to appendix 9. This AC complements existing guidance.
c . In this AC, terrain awareness and warning system (TAWS) refers to a system used for fixed-wing aircraft and helicopter terrain awareness and warning system (HTAWS) refers to a system used for rotorcraft.
d. This AC is not mandatory and does not constitute a regulation. This AC describes an acceptable means, but not the only means, to install enhanced and synthetic vision technologies. However, if you use the means described in this AC, you must follow it in all aspects.