ILS & VOR Systems Overview

The range of frequencies used in VOR systems, displaying 30 Hz signals.

The transmitter's signals are in phase at magnetic north, changing with bearing.

The difference in phase between variable and reference signals indicates aircraft bearing.

A keyed AM audio frequency signal for identifying stations at least every 10 seconds.

International standards suggest station ID every 10 seconds using Morse code.

The signal produced by mixing a received signal with a synthesizer frequency.

The difference signal produced comparing the 90 Hz and 150 Hz tones.

A device that uses Δ signal to show horizontal and vertical deviation course pointers.

Works similarly to the localizer receiver but operates in the UHF band for glideslope signals.

Self-checking system in ILS ground equipment that ensures signal parameters are met.

Displays the magnetic bearing from a VOR station on the OBS.

Defined as a radial from one VOR station to the reciprocal of the next.

Antennas best suited for VOR navigational receivers, producing omnidirectional patterns.

The frequency band used for VOR localizer signals and other navigational systems.

Device allowing pilots to select their intended radial from a VOR station.

Frequencies that are integer multiples of a fundamental frequency.

A sound frequency of 90 Hertz, often used in modulation.

A sound frequency of 150 Hertz, also used in modulation.

Frequency range for localizer signals: 108.10 MHz to 111.95 MHz.

Frequency range for glideslope signals: 329.5 MHz to 335.0 MHz.

Output signal change of 75 µAmps at 1º deviation.

Signal output change of 75 µAmps for a 0.35º deviation.

Speed at which an aircraft descends in feet per minute.

Instrument Landing System that aids in precision landings.

Speed of the aircraft relative to the ground.

A radio navigation system using frequencies between 108-118 MHz for aircraft position referencing.

VOR operates in the 108-118 MHz band with 50 KHz channel spacing.

VOR produces 360 possible radials from a beacon for aircraft navigation.

A transmitter that emits signals allowing aircraft to determine their position.

VOR is nearly static-free, making it reliable at any time, day or night.

The VOR band shares frequency with ILS localizer, aiding in precision approaches.

VOR operates like a lighthouse, emitting signals periodically to indicate direction.

Part of the ILS that provides vertical guidance for landing, distinct from VOR's horizontal guidance.

The audio tone of VOR is filtered and amplified for the cockpit speaker.

The phase comparator compares variable and reference 30 Hz signals for phase difference.

Detected phase difference is converted into voltage for RMI display.

Course deviation left/right and TO-FROM indications are derived from signal phase relationships.

A red warning flag appears for detected issues like power failures or weak signals.