ILS Flashcards
What is the function of the localizer in an ILS approach?
Provides lateral guidance.
Where is the localizer antenna typically located?
At the departure (opposite) end of the runway.
How sensitive is the localizer signal compared to a VOR?
Four times more sensitive; full deflection is 2.5° off center.
What is the coverage range of the localizer signal?
10NM within 35° offset, and 18NM within 10° offset from the centerline.
What is the typical vertical descent angle provided by the glideslope in an ILS approach?
3° vertical descent angle.
Where is the glideslope transmitter typically located?
Abeam the aiming point on the runway.
What does the outer marker indicate in an ILS approach?
The glideslope intercept, typically 4-7 miles out from the runway.
What does the middle marker signify on an ILS approach?
Typically 3500 feet from the runway, at decision height.
What is the inner marker used for in an ILS approach?
Indicates decision height for Category II ILS approaches.
How do you fly the localizer on a backcourse approach?
Fly away from the needle due to reverse sensing.
Why can’t the glideslope be used in a backcourse approach?
The glideslope signal is not usable on the backcourse, making it non-precision.
