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to be followed and the criteria that must be met before the path concludes and the next path begins. Although there are 23 leg types available, none of the manufactured database equipment is capable of using all of the leg types. Pilots must continue to monitor procedures for accuracy and not rely solely on the information that the database is showing. If the RNAV system does not have the leg type 

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demanded by procedures, data packers have to select one or a combination of available lleg types to give the best approximation, which can result in an incorrect execution of the procedure. Below is a list of the 23 leg types and their uses that may or may not be used by all databases. 

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• Initial fix or IF leg—defines a database fix as a point in space and is only required to define the beginning of a route or procedure. [Figure 6-5] 

• Track to a fix or TF leg—defines a great circle track over the ground between two known database fixes and the preferred method for specification of straight legs (course or heading can be mentioned on charts but designer should ensure TF leg is used for coding). [Figure 6-6] 

• Constant radius arc or RF leg—defines a constant radius turn between two databases fixes, lines tangent to the arc, and a center fix. [Figure 6-7] 

• Course to a fix or CF leg—defines a specified course to a specific database fix. Whenever possible, TF legs 

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