Predictive EGPWS function must be manually inhibited during QFE operations, when GPS data is unavailable or inop. Which button is used to inhibit predictive EGPWS?

Predictive EGPWS function must be manually inhibited during QFE operations, when GPS data is unavailable or inop. Which button is used to inhibit predictive EGPWS?

• A. GRD PROX TERR INHIB
• B. EGPWS OFF
• C. GPS INHIB
• D. THR INHIB

Answer: (A)

The function being tested is how to disable the predictive terrain/GPWS logic when GPS data isn’t reliable, such as during QFE operations. The button to use is the GRD PROX TERR INHIB pushbutton. It specifically disables the ground proximity and terrain predictive warnings, allowing you to operate safely when GPS is unavailable or being used with local elevation references. Using EGPWS OFF would turn the system off entirely, which isn’t desirable; GPS INHIB isn’t the correct control for this scenario; and THR INHIB has no relation to GPWS terrain logic.

The function being tested is how to disable the predictive terrain/GPWS logic when GPS data isn’t reliable, such as during QFE operations. The button to use is the GRD PROX TERR INHIB pushbutton. It specifically disables the ground proximity and terrain predictive warnings, allowing you to operate safely when GPS is unavailable or being used with local elevation references. Using EGPWS OFF would turn the system off entirely, which isn’t desirable; GPS INHIB isn’t the correct control for this scenario; and THR INHIB has no relation to GPWS terrain logic.