What is a glideslope antenna?

A glideslope antenna broadcasts radio signals to guide an aircraft vertically to the runway. The glideslope transmitter antenna is horizontally polarized. The transmitting frequency range is UHF between 329.3 MHz and 335.0 MHz. The frequency is paired to the localizer frequency of the ILS.

What is the purpose of glideslope?

A glide slope provides vertical (up/down) guidance toward the runway touchdown point, usually at a 3° slope. Marker beacons provide range information along the approach path. Approach lights assist in the transition from instrument to visual flight.

What causes false glideslope?

Objects below 5,000 feet AGL have a tendency to reflect glideslope signals. This can create false glideslopes, which are often at 9 degree and 12 degree angles to the runway. This is why pilots are always taught to intercept the glideslope from below, to ensure they don’t capture a “false” glideslope.

Are marker beacons required for ILS?

b. Middle Marker (MM) beacons are not required for CAT I/II/III ILS. An IM is only required for CAT II operations below RVR 1600 that do not have a published RA minimum (refer to Appendix A).

What is glideslope warning?

When the crew is making an instrument landing system—ILS—approach, mode 5 announces “Glide slope” if the aircraft has deviated below a safe flight path to the runway. Another operating mode calls out altitudes during descent, and the last warns of significant wind shear.

How can you tell a fake glideslope?

A pilot can easily recognize this false indication by the steeper-than-normal rate of descent. Pilots will not experience false glide-slopes below the true glide-slope angle. Pilots can avoid encountering a false glide-slope by following published approach procedures.

What is the purpose of GPWS?

The Ground Proximity Warning System (GPWS) generates advisory Alerts and mandatory response Warnings to the flight crew in respect of their proximity to terrain.