Download - Instrument Navigation
Instrument Navigation
Chapter 2, Section C
VOR Navigation
Ground Based Transmitter 360 Radials Aligned with magnetic north Directional Line of sight
VOR Ground Facility
Ground Facilities - VOR Operate in 108.0 - 117.95 MHz Band Standard Service Volumes (SSV)
High Altitude(HVOR) - 200 watts, up to 130 nm, used for airways
Low Altitude(LVOR) - about 100 watts, up to 40 nm, used for airways
Terminal(TVOR) - 50 watts, 25 nm, used for approaches
VOR Receiver Checks VOT
180o TO, 360o FROM; +/- 4o VOR Ground Checkpoint
Indicated radial; +/- 4o
VOR Airborne Checkpoint Indicated radial; +/- 6o
Centerline of airway; +/- 6o Dual VOR Check
Within 4o
Using the VOR CDI To-From Indicator Intercepting a radial Tracking
wind correction Station passage
cone of confusion Reverse sensing
Omni Bearing Selector Course Deviation Indicator
TO/FROMRotating Course Card
Using the VORBasic VOR Indicator
each dot on CDI is 2o
full scale deflection is 10o
1 deg in 60 nm is 1 nm OBS
Horizontal Situation Indicator HSI incorporates HI, CDI, Glideslope makes easier to scan not reverse sensing except for using on BC
VOR Time & Distance Calculations
90 deg Method (no wind) Time to station=Time(sec)/bearing
change
VOR Time Distance - 900
Time to station (min)
Established inbound on a radial rotate the obs 10o to the left, turn the aircraft 10o to the rightNote the time and maintain heading until the cdi centers
60 x Min flown between bearing change Degrees of bearing change
Distance To station (NM)
TAS X Min. flown between bearing change Degrees of bearing change
Isosceles Triangle
5 minutes
A
B
C
5 minutes
ADF Navigation
Ground based transmitter Low/medium frequency (AM) Non-directional beacon (NDB) Not line of sight No receiver checks No flags - listen to Morse code
Operational Considerations
NDB Compass locator (LOM) - 25 watts, 15
NM MH - less than 50 watts, 25 NM H - 50 to 1999 watts, up to 50 NM HH - 2,000 watts or more, 75 NM
Using the ADF (fixed card) Magnetic heading + relative bearing =
magnetic bearing Intercepting a bearing Tracking
wind correction to the station from the station
Time and distance to a station Station passage
Rotating Card
DME
Ground based - VOR/DME, VORTAC, ILS/DME, LOC/DME
Interrogation and response rate * time = distance
Uses slant distance - 1 NM away for each 1000’ elevation
Area Navigation
VOR/DME, VORTAC based Phantom VORs
INS Self Contained
LORAN
Radio Magnetic Indicator RMI
HI, 1 or 2 pointers for the different stations
Pointers show the bearing to the station without mental calculations
Tail of the VOR pointer is the radial you are on
Global Positioning System(GPS
Describe how it works. A fog horn blows on the hour, … speed
of sound is 550 ft/s.Same for GPS except using speed of light.Accuracy within 300 meters 99.99% of timeVertical accuracy is not great. Accuracy can be improved by DGPS
Global Positioning System(GPS)
RAIM continuously monitors signals received
for validity required for IFR GPS
Global Positioning System(GPS)
Two Main types of IFR GPS enroute approved approach approved database must be updated frequently database contains info about airports,
intersections, VOR, NDB, etc
Lack of Standardization among manufacturers
GPS ApproachesGenerally has a LCD or LED CDI
“fly to the bars”
when navigating 30 miles away 1 dot is 1 nm, 5 nm full scale deflection
when closer ramps to 1 nm full scale deflection
as you fly the approach ramps down to 0.3 nm full scale deflection