This Aerospace Standard (AS) defines the requirements for a metallic reinforced, duct assembly suitable for use in low pressure, 350 °F ground heaters.

Classification:

The duct assemblies shall be of the following sizes and length as specified (see 6.2).

a. Size A shall be 12 inches nominal diameter, 15 feet nominal length.

b. Size B shall be 6 inches nominal diameter, 15 feet nominal length.