What is the frequency of the glide slope (GS) at the top and bottom?

The glide slope transmission operates on a specific frequency modulation that is crucial for precision approach and landing. The glide slope signal is typically divided into two distinct frequencies: at the top, it operates at a frequency of 90 Hz, and at the bottom, it operates at 150 Hz.

These frequencies are integral to how aircraft receive glide slope information. The 90 Hz frequency is transmitted as the upper signal ensuring a proper approach angle, while the 150 Hz frequency forms the lower signal which helps the pilot maintain the desired glide path. This modulation allows the aircraft's navigation systems to interpret the signals effectively, ensuring safe and accurate landings.

Understanding these specific glide slope frequencies is essential for pilots as it directly affects the approach and landing phases of flight. By knowing the correct frequencies, pilots can ensure that their instruments are tuned correctly and that they are receiving the proper guidance during the approach to landing.