Navigation Aids and Instrument Approaches

Navigation aids used during an approach to landing that do not provide vertical guidance to the pilot.

Navigation aids used during an approach to landing that do provide vertical guidance to the pilot.

Navigation aids, like VOR, TACAN, and NDB, that were initially developed for en route navigation but can also be used for nonprecision approaches.

A type of nonprecision approach aid that uses a radio signal to provide horizontal guidance to the runway.

The FAA certifies navigation aids to ensure they meet quality standards for safe use as nonprecision approach aids.

A UHF signal modulated at 90Hz and 150Hz used in ILS to guide aircraft towards the runway.

The horizontal needle on the ILS indicator, which moves up or down to guide the aircraft along the glide path.

A 90Hz signal predominates, causing the ILS needle to move down. The pilot should fly down to correct the aircraft's position.

A 150Hz signal predominates, causing the ILS needle to move up. The pilot should fly up to correct the aircraft's position.

The aircraft is aligned correctly with the glide path, and the ILS needle is in the middle.

A specific area directly in front of the glide slope antenna used to reflect the signal and reduce the antenna's height.

False glide paths created when the glide slope signal bounces off the ground. These paths are usually higher than the correct glide path.

An obstruction in front of or to the side of the glide slope transmitter can cause distortion in the signal, resulting in a wavy glide path.

A system that measures runway visibility using a projector and detector. The projector emits light, and the detector measures the intensity of light received, which is then converted into a visibility value in feet.

The instrument that projects a beam of light used to measure runway visibility.

The instrument that detects the intensity of the light projected by the RVR projector, giving a measure of visibility.

The position on the runway where the RVR equipment is typically installed to provide visibility measurements for incoming aircraft.

Indicates the visibility conditions at the point where the aircraft touches down on the runway.

Indicates visibility conditions at the point where the aircraft is rolling out on the runway after landing.

A navigational aid providing less accurate course guidance than an ILS localizer, suitable for smaller airports or as a secondary approach.

The component of an ILS that provides horizontal guidance for an aircraft during an approach.

A designated area directly in front of the glide slope antenna, which must be kept clear of obstructions to ensure the proper operation of the glide slope system.

A ground-based transmitter that emits a radio signal used to guide aircraft during instrument landing system (ILS) approaches.

The angle at which an aircraft descends during an ILS approach, determined by the glide slope transmitter.

Receivers located within the glide slope critical area that monitor the strength and accuracy of the glide slope signal.

Radio beacons that transmit a coded signal at a specific frequency to provide pilots with information about their position during an ILS approach.

A marker beacon located approximately 5 miles from the runway end, indicating the outer edge of the ILS approach.

A marker beacon located approximately 3,000 feet from the runway end, indicating the middle marker point of the ILS approach.

A cone-shaped signal used by marker beacons to provide position information to pilots.

An approach guidance system combining WAAS, EGNOS, or LAAS with runway and approach lighting, providing vertical guidance for landings.

An approach guidance system using LNAV/VNAV, providing vertical guidance with a decision altitude around 250 to 350 feet above the runway.

An approach guidance system providing pilots with vertical guidance and precise landing capabilities, similar to Category I ILS systems.

Theoretically, LPV could replace ILS systems by providing precise vertical guidance and landing capabilities, potentially replacing Category II and III ILS systems.

When night flying was introduced, airport runways were primarily made of turf or cinders, lacking proper lighting for safe landings.

The introduction of airport boundary lighting helped pilots identify airports but still lacked precise guidance for landing.

To improve safety and accommodate heavier aircraft, most airports transitioned from cinders to concrete runways by the late 1930s.

The introduction of concrete runways paved the way for safer and more efficient air travel.

A non-precision approach using GPS for lateral guidance, but without vertical guidance. Aircraft descend incrementally to minimum altitude and level off, similar to VOR or NDB approaches.

A precision approach using GPS for both lateral and vertical guidance. Pilots receive a calculated glidepath from the GPS receiver, allowing for lower minimums than LNAV approaches.

A non-precision approach specifically utilizing RNAV equipment for lateral guidance. Aircraft descend incrementally to a minimum altitude and level off.

A type of approach procedure using calculated vertical guidance from GPS instead of a traditional glide path.

A precision approach using WAAS (Wide Area Augmentation System) to provide highly accurate lateral and vertical guidance. Offers Category I ILS capability.

A future potential enhancement to LPV using LAAS (Local Area Augmentation System). May enable Category II and III approaches.

A non-precision approach using GPS for lateral guidance only. Aircraft descend incrementally to minimum altitude and level off. Similar to VOR and NDB approaches.

The lowest allowable altitude for an aircraft during the final approach to landing