Signal Corps Field Manual Aircraft Warning Service — FM 11-25

The purpose of the manual is to outline the Aircraft Warning Service and its agencies, to prescribe its mission and the responsibilities of various agencies concerned, to describe its functions, to cover the organization of its agencies, the observation and signal communication systems, and to prescribe operating procedures for the service. Variations from standard equipment and procedure are authorized where such variations are made mandatory by local conditions. This manual is based upon Field Service Regulations (FM 100 series) and is supplementary to FM 24-5 and FM 11-5.