Definition
The equipment installed in the aircraft that receives and displays Instrument Landing System (ILS) signals. These components include the localizer receiver (which interprets horizontal guidance to the runway centerline), the glide slope receiver (which interprets vertical guidance to the touchdown point), and the marker beacon receiver (which signals the aircraft's position along the approach). Together they translate the ground-transmitted ILS signals into cockpit indications the pilot uses to fly a precision approach.
Plain English
The parts of the ILS that live in the airplane. They pick up the signals beamed from the ground and turn them into needles, lights, and tones in the cockpit so the pilot can line up with the runway and descend at the right angle.
Context Anchor
Seen in instrument approach training, especially when learning how an ILS approach is received and shown in the cockpit.
Derivation
"Airborne" simply means "carried in the air" — here it distinguishes the equipment in the aircraft from the matching equipment on the ground. ILS has two halves: the ground side (transmitters at the airport) and the airborne side (receivers in the aircraft). This term refers only to the airborne half.
Why Pilots Care
A pilot must confirm these components are installed, powered, and functioning to legally fly an ILS approach and to receive accurate lateral and vertical guidance.
Intuition Check
Do not confuse ILS airborne components with the ILS equipment on the ground near the runway. Airborne components are the aircraft-side parts that receive and show the guidance; ground components transmit the guidance signals.
Example Sentence 1
During the avionics check, the pilot verified that all ILS airborne components — the localizer, glide slope, and marker beacon receivers — were operating correctly.
Example Sentence 2
A malfunction in one of the ILS airborne components can cause the course deviation indicator to give unreliable guidance.