Individual satellites can be deselected from use by entering the identifier for the satellite on the FMS GPS control page.

• A. True
• B. False
• C. Only when the aircraft is in approach
• D. Not available

Answer: (A)

The concept being tested is manual control of which GPS satellites contribute to the navigation solution. By entering a satellite’s identifier on the FMS GPS control page, you can deselect that satellite so it won’t be used in calculating position and timing. This is useful when a satellite shows poor signal quality or adverse geometry, allowing the system to rely on the remaining healthy satellites for a more accurate and reliable solution. The capability is available during normal operations, not restricted to a specific phase like approach, and it isn’t unavailable.