When you create a new Project with default settings, the FTA module is set up for time dependent trees. If you want to construct Lambda Tau or SAE trees, you must select Lambda Tau or SAE ARP4754A and ARP4761 as the FTA calculation type in the properties for the System file prior to inserting any events in the tree. For more information, see FTA System File Properties. To have all System files in a Project be set up for Lambda Tau or SAE trees, you must select Lambda Tau or SAE ARP4754A and ARP4761 as the default FTA calculation type in the Project properties. For more information, see FTA Project Properties. However, for SAE trees, the best practice is to use the New Project Wizard to create an SAE Project from the supplied FTA Civil Aerospace Template. This sets up the Project so that SAE ARP4754A and ARP4761 is the default FTA calculation type for all System files. It also sets up the FTA tables in System files to contain SAE-specific fields.