Navigation and Radio Aids Flashcards
7 cards from real CPL practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Navigation and Radio Aids flashcards as text
Why does the ILS localizer beam width vary from one runway installation to another?
Answer: To ensure full-scale CDI deflection always represents approximately ±350 ft at the runway threshold regardless of runway length
The localizer beam width (typically 3°–6°) is adjusted for each installation so that full-scale deflection equals approximately ±350 ft (700 ft total) at the runway threshold.
What is the standard ILS glideslope angle published on most approach procedures in the United States?
Answer: 3.0°
The standard ILS glideslope angle is 3.0°, equating to roughly 300 ft of descent per nautical mile (approximately a 5:1 glide ratio).
The ILS outer marker (OM) is identified in the cockpit by:
Answer: Continuous dashes at 400 Hz with a blue/purple light
The outer marker transmits a 400 Hz tone as continuous dashes (- - -) and illuminates a blue or magenta cockpit light.
An ILS back course approach uses which signal and serves which runway?
Answer: The rear radiation of the localizer antenna; it guides aircraft to the opposite runway end from the front course
The ILS back course uses the rearward-radiating lobe of the localizer antenna to provide horizontal guidance to the opposite end of the runway from the front course.
When flying an ILS back course approach without an HSI or 'BC' mode selected, CDI sensing is:
Answer: Reversed — the pilot must turn away from the CDI needle to stay on course
Without an HSI or back-course mode, flying toward the CDI needle on a back course will take the aircraft off course; the pilot must fly away from (opposite to) the needle.
During an ILS approach with the localizer centered, the glideslope needle is at full-scale deflection UPWARD. This means the aircraft is:
Answer: Below the glideslope and on the localizer centerline
A full-scale up glideslope indication means the glideslope signal is above the aircraft — the aircraft is below the glideslope — while the centered localizer confirms it is on centerline.
ILS localizer frequencies are allocated in the range:
Answer: 108.10–111.95 MHz, using only odd-tenth decimal channels
Localizers operate on VHF frequencies from 108.10 to 111.95 MHz, exclusively on odd-tenth channels (e.g., 109.1, 110.3), which are automatically paired with their UHF glideslope frequencies.