Are the antenna arrays on the Collins ANT-310/312/318 radar antenna assemblies not included with the purchase of the ANT units?
No, unlike the Bendix line of radar antenna assemblies, the antenna array is part of the final assembly part number. For example, part numbers 622-2502-001, 622-2501-001, and 622-2504-001 have the antenna arrays installed on them already. Thus, the differentiation between the sizes of the antenna arrays (i.e. 10″, 12″, 18″).