NAVAIDS Flashcards
What is a precision approach aid?
An approach aid providing elevation information
What 2 beams does an ILS emit?
Localiser (Azimuth) and Glidepath (elevation)
Glidepath coverage in the vertical plane typically extends……
From 0.45 to 1.75 times the glidepath angle.
ILS Cat I
RVR: 550m
Decision Height: 200ft
ILS Cat II
RVR: 250m
Decision Height: 100ft
ILS Cat IIIa
RVR 200m
Decision Height: 0ft
ILS Cat IIIb
RVR: 50m
Decision Height: 0ft
ILS Cat IIIc
RVR: 0m
Decision Height: 0ft
Limitiations of ILS:
Inflexible, expensive, beam must always be protected, aircraft must be fully out of the way before next plane can approach to land.
What frequency band do the Localiser and Glidepath work on?
Localiser VHF Glidepath UHF
What degree slope is a glidepath usually?
3 degrees
ILS have Outer Middle and Inner Markers…
Lights and sounds in the cockpit will inform the pilot once passing each of these phases.
An instrument approach contains 5 phases. Name them?
Initial approach fix, intermediate approach fix, final approach fix, final approach point, missed approach point
The arrival phase means?
The aircraft has left the en-route phase of flight and has navigated to the IAF.
The initial segment means?
The segment between the IAF and IF.
The Final approach segment means?
The segment of instrument approach in which alignment and descent for landing are accomplished.
What is the missed approach point?
The point at or before a missed approach procedure must be implemented to ensure minimum obstacle clearance is not infringed.
What is minimum descent height/altitude?
In a non-precision approach below which a descent may not be made without the required visual reference.
Waypoints are usually?
5 Letter designators which should spell a pronounceable word.
INS means?
Inertial Navigation Systems. An en-route navigation aid. Comprises also of programmed waypoints but accuracy decays and must be updated regularly otherwise GIGO - Garbage I Garbage Out
FMS means?
Flight Management System. Varies in complexity with newer models almost completely guiding plane from take-off to landing.
The FMS gathers data from?
Multiple sources, including INS and Navaids to ensure the aircraft is performing as desired. It feeds the autopilot.
FDI means:
Flight Director Interface. Pilot can update changes to the preprogrammed flight here.
GPS is?
Global Positioning System. Precision 3D satellite navigation aid. Operates on 2 L Band frequencies: 1575.42 MHz & 1227.6 MHz
Limitations of GPS?
Number of satellites available, signal degredation, military control.
What is a VOR?
Very High Frequency Omni-Directional Range. An en-route and terminal instrument approach aid. Orientated to magnetic north and emits 360 radials to plus or minus 1 degree accuracy. The receiver compares the phase difference between two signals and determines the a/c bearing from the station.
What is a CDI?
Course Deviation Indicator. Part of a VOR instrument that shows a/c alignment with desired VOR radial.
DME suffers from a type of error known as?
Slant error. Less prevalent at lower altitudes where the diagonal distance doesn’t necessarily align with horizontal distance from station.
NDB is a?
Non Directional Beacon. A basic en route and approach aid that emits a radio signal equally in all directions. Pilot navigates towards this.
NDB’s can be affected by many types if interference. Name them?
Station interference, night effect, coastal refraction (unless crossing coast at 90 degrees), mountain effect, quadrantal error (less error when signal aligns with nose/wings/tail)
