How does the aircraft handle GPS outages in navigation?

How does the aircraft handle GPS outages in navigation?

• A. Switch to auto-locate via ground beacons.
• B. It relies on the IRS/ADIRU data and other sensors to maintain position until GPS is restored.
• C. GPS outages trigger immediate autopilot disengagement.
• D. Pilot must manually estimate position and input new coordinates.

Answer: (B)

When GPS is unavailable, the aircraft’s navigation system switches to inertial navigation using the IRS/ADIRU data. These units collect measurements from gyros and accelerometers to track movement, attitude, and heading, and they continually integrate that information to estimate the aircraft’s position. The FMS uses this inertial data, along with other sensors (like air data, magnetometer as applicable, and related systems), to maintain a current position and track until GPS is restored. This provides a graceful degradation rather than a sudden loss of navigation capability. Ground-based beacons aren’t used for automatic re-location in this scenario, and GPS outages do not automatically disengage autopilot—the systems continue to navigate using the inertial data, though with degraded accuracy. Pilots don’t need to manually input coordinates; the aircraft remains navigated by the IRS/ADIRU and supporting sensors until GPS returns.

When GPS is unavailable, the aircraft’s navigation system switches to inertial navigation using the IRS/ADIRU data. These units collect measurements from gyros and accelerometers to track movement, attitude, and heading, and they continually integrate that information to estimate the aircraft’s position. The FMS uses this inertial data, along with other sensors (like air data, magnetometer as applicable, and related systems), to maintain a current position and track until GPS is restored. This provides a graceful degradation rather than a sudden loss of navigation capability.

Ground-based beacons aren’t used for automatic re-location in this scenario, and GPS outages do not automatically disengage autopilot—the systems continue to navigate using the inertial data, though with degraded accuracy. Pilots don’t need to manually input coordinates; the aircraft remains navigated by the IRS/ADIRU and supporting sensors until GPS returns.