This SAE Aerospace Standard (AS) covers combustion heaters used in the following applications: a. cabin heating (all occupied regions and windshield heating); b. wing and empennage anti-icing; c. engine and accessory heating (when heater is installed as part of the aircraft); d. aircraft de-icing.This document details the minimum safety, performance, design, and testing requirements for combustion heaters and certain auxiliary devices that are considered necessary for the utilization of heaters in fixed and rotary wing aircraft. This standard is to be considered currently applicable and necessarily subject to revision from time to time due to advances in the aircraft industry. This standard is based on practical engineering requirements for aircraft heaters currently in use and is applicable to aircraft heaters that shall be developed to meet future requirements.The requirements of this standard are primarily intended to be applicable to civil aircraft whose primary function is transporting passengers or cargo.