Instrument Rating Checkride Practice Test

Which GPS systems refer to non-WAAS capable equipment?

1. TSO-C145 and TSO-C146

2. TSO-C129 and TSO-C196

3. TSO-C152 and TSO-C158

4. TSO-C132 and TSO-C189

The correct answer is: TSO-C129 and TSO-C196

The correct choice identifies TSO-C129 and TSO-C196 as GPS systems that are not WAAS capable. To understand why this is the case, it’s important to know what WAAS is and how different TSO (Technical Standard Order) designs relate to it. WAAS, or Wide Area Augmentation System, enhances the accuracy and reliability of GPS signals, making it possible to use them for precision approaches and landings. TSO-C129, which was developed for GPS navigational equipment prior to WAAS availability, does not include support for WAAS signals. Similarly, TSO-C196, which serves a similar purpose, also lacks WAAS capability. In contrast, TSO-C145 and TSO-C146, listed in the first choice, are specifically designed for WAAS capability and provide enhanced navigation performance. TSO-C152 and TSO-C158 also support WAAS, focusing on advanced capabilities suitable for various aviation applications. TSO-C132 and TSO-C189, while applicable to certain aviation needs, do not pertain to equipment that is inline with the non-WAAS classification established in the question. Understanding these distinctions allows pilots and operators to select the correct GPS systems based on their operational requirements, particularly regarding IFR