FAA Instrument Rating Airplane (IRA)Navigation SystemsEasy
During an ILS approach, a pilot notices that the glide slope indicator is showing full deflection below the center. What does this indicate?
- AThe aircraft is below the glide slope and needs to climb.
- BThe aircraft is above the glide slope and needs to descend.
- CThe aircraft is to the left of the localizer course.
- DThe aircraft is to the right of the localizer course.
Show answer & explanationAnswer & explanation
Correct answer: B. The aircraft is above the glide slope and needs to descend.
On an ILS glide slope indicator, if the needle is deflected below the center, it means the aircraft is above the desired glide path and needs to descend to intercept it.
Why the other options are wrong
- A. A needle deflected above center would indicate being below the glide slope.
- C. Localizer indications relate to left/right position, not up/down.
- D. Localizer indications relate to left/right position, not up/down.
ILS Glide Slope Indication
The vertical needle on an ILS indicator shows the aircraft's position relative to the desired glide path.
- Needle centered: on glide slope.
- Needle above center: below glide slope (need to climb).
- Needle below center: above glide slope (need to descend).
Memory trick: Needle shows where the glide slope is relative to you.