What does FDE stand for in aviation navigation?

• A. Flight Data Error
• B. Fault Detection System
• C. Fault Detection Exclusion
• D. Fuel Density Estimator

Answer: (C)

In aviation navigation, FDE refers to Fault Detection and Exclusion. This is the process by which the navigation system identifies faulty measurements or satellite signals that could distort the position solution and then excludes those bad data from the calculations. The goal is to preserve the integrity and reliability of the navigation solution, which is crucial for IFR operations and RNAV accuracy. The term is specifically about detecting faults and removing their influence, not about generic data errors, a separate system, or unrelated calculations. That’s why the option describing fault detection and exclusion best matches the standard terminology used in navigation integrity.