2021 Navigation Flashcards
What is a meridian?
Line of LONGITUDE that connect the poles (north to south lines).
Called TRUE meridians because they connect the geographic poles, NOT the magnetic poles.
What is the Prime Meridian?
Line which passes through Greenwich, England. Numbered 0°.
What is longitude?
Measured from 0° to 180° east and west of the Prime Meridian. (UP AND DOWN LINES).
How are longitudes measured?
Degrees(°), Minutes(‘), Seconds(‘’).
60 minutes in a degree and 60 seconds in a minute.
What is latitude?
Line of Latitude, which runs parallel to the equator.
What is the equator?
A great circle on the surface of the earth lying equidistant from the poles.
How is latitude measured?
From 0° to 90° north or south of the equator (equator is 0°).
Latitude is also measured in degrees(°), minutes(‘), seconds(‘’)
What is a Great Circle?
Shortest distance between 2 points on a map; constantly changing heading to achieve it.
What is a Rhumb Line?
A straight line where you can follow a heading between 2 points. This is the longer way.
What is Variation?
The difference in angle between geographical (true) poles and magnetic poles (magnetic).
What is annual change?
The change in variation due to the magnetic poles constantly changing; occurs from year to year.
What is isogonal?
Isogonic lines are lines that join areas having the same variation.
Isogonal lines or isogonic lines are not straight; they bend with the influence of magnetic fields below the earth’s surface.
What is an agonic line?
Agonic lines are lines drawn through places of zero variation.
Agonic lines are not straight; they bend with the influence of magnetic fields below the earth’s surface.
What do isogonic and agonic lines have in common?
They both are not straight & are influenced by the magnetic field of local magnetic bodies beneath the earth’s surface.
What is deviation?
The angular difference between compass heading and magnetic heading.
What is the difference between air position and ground position?
Air position is your position for the aircraft assuming no wind.
Ground position is a distance and direction equal to the speed and direction of the wind for a period of time in flight.
What is bearing?
Usually measured clockwise from true north magnetic north or any other reference point through 360 degrees.
4 basic elements of map construction:
- Areas
- Distances
- Shapes
- Bearing
ADSB!
What are Meridians on Lambert Conformal Conic Projection charts?
They are curves or straight lines converging towards the nearer pole.
On a Lambert Conformal Conic Projection chart, what do the meridian lines represent to each other?
They represent an angle, which is called convergency. It varies with latitude!
At equator, there is no convergency between meridians. Near the poles (at a higher latitude), the angle of convergency is at its highest.
How are the parallels of latitude viewed on a Lambert Conformal Conic Projection chart?
The parallels of latitude curve towards or ‘around’ the nearest pole.
Curvature is considerable on smaller charts!
When you draw a straight line on a Lambert Conformal Conic Projection map, what does it represent?
Represents a great circle line.
What is a rule of thumb regarding heading changes on a Lambert Conformal Conic Projection map?
“To make good a given track”
Change heading 2° for every 3° of longitude.
Flying east, the 2° is added. Flying west, the 2°is subtracted.
What are VNC and WAC charts projected as?
Lambert Conformal Conic Projection.
What charts utilize Lambert Conformal Conic charts?
VFR Navigation charts (VNC)
World Aeronautical Charts (WAC)
LO charts
How are meridians projected on a Mercator Projection chart?
Meridians are straight and parallel lines.
How are latitudes projected on Mercator Projection charts?
Latitudes are straight and parallel lines.
When you draw a straight line on a Mercator Projection chart, what does it represent?
Represents a rhumb line.
What is an adverse effect of Mercator Projection?
There is no constant scale of distance; areas are greatly exaggerated in high latitudes.
How can you use the longitude scale on a Mercator Projection chart?
The longitude scale should only be used for marking the longitude of a place.
NO, never use longitude scale on a Mercator Projection map for measuring distance.
LOOONG distance = NO MEASURING
How can you use the latitude scale on a Mercator Projection chart?
Can be used to measure distance.
How can the latitudes be used on a Mercator Projection chart?
Since 1 minute of latitude always equals 1 nautical mile, the latitude scale is used for measuring distance.
What is Transverse Mercator Projection? How does it work?
It is essentially a fix for distortion of distances of regions of high latitudes on Mercator Projection.
Transverse Mercator works by rotating the “cylinder” or map 90 degrees, so that a point of tangency is a meridian, versus the equator.
What is a benefit of Transverse Mercator Projection?
Accurate in depicting scale, especially on charts for relatively small areas.
In addition, you can select any meridian of longitude to be the reference point, depending on your region of flight.
What maps are based on Transverse Mercator projection?
VFR Terminal Area charts (VTA).
Smaller area, more accuracy with Transverse Mercator!
What projection is used for VTA’s?
Transverse Mercator Projection.
What is the scale of VFR Navigation Charts (VNCs)?
1:500,000; 1 inch to 8SM!
What is the scale of World Aeronautical Charts (WACs)?
1:1,000,000; 1 inch to 16SM!
What is the scale of a VFR Terminal Chart (VTA)?
1:250,000; 1 inch to 4SM!
What are hypsometric tints?
The colour-coding range from green to yellow to bronze depicting height in terrain (1,000ft increments).
What are contours?
Contour lines are lines drawn on a chart joining points of equal elevation. The closer the lines, the steeper the inclination of terrain.
What are position lines?
Are attained by observing the bearing of two or more objects that are plotted on a map or chart to fix a position.
What is the 1 in 60 rule?
An error in track of one degree will cause an error in position of 1 mile after travelling 60 miles.
Error in distance / Distance travelled = 1NM / 60NM
Why are HF signals unpredictable?
Because HF bands are reflected back down to earth by the ionosphere.
The ionosphere varies from day to night and is affected by sunspots, auroras, etc.
Do HF stations in the upper range have greater or smaller reception during daylight or night?
Upper range HF stations have greater reception distance during daylight hours.
Sun up, frequency up!
Sun Down, frequency down!
Do HF stations in the lower range have greater or smaller reception distance during daytime or night time?
Lower range HF stations have greater reception distance during night time hours.
Sun up, frequency up!
Sun Down, frequency down!
What frequency band do Non-Directional Beacons (NDBs) operate on?
ON the low/medium frequency bands (LF/MF) of 200 KHz to 415 KHz and 510 KHz to 535 KHz.
What is the frequency range & purpose for HF signals?
2,500 KHz TO 30,000 KHz
HF has much longer range than VHF and is used for air/ground communications to aircraft in remote areas.
What frequency is the designated HF air/ground communication channel in the remote areas of Canada?
5,680 KHz.
What is a Single Sideband HF (SSB) signal?
Allows for transmissions to be carried over significant distances.
It compresses speech and other intelligences into a narrower bandwidth.
How do you calculate true airspeed?
For every thousand feet the difference between IAS and TAS is 2%.
How do you calculate true airspeed?
For every thousand feet the difference between IAS and TAS is 2%.
What are the four variables needed to calculate a 3D fix for an aircraft on GPS?
Altitude, Time, Latitude, Longitude.
“ATLL” Atlanta with two L’s.
What is SFG/C as entered in a flight plan?
S - standard (VHF,RTF,VOR,ILS)
F - ADF
G - GNSS (GPS)
C - LORAN C (mode C and S transponder)
When flying enroute, a pilot had tuned an NDB. He is currently flying a heading of 290 degrees. They read a relative bearing to an NDB of 210 degrees. What is the relative bearing to the NDB?
Relative bearing = Bearing to Station - Magnetic Heading
Bearing to station = BFM?
When flying enroute, a pilot had tuned an NDB. He is currently flying a heading of 290 degrees. They read a relative bearing to an NDB of 210 degrees. What is the relative bearing to the NDB?
Relative bearing = Bearing to Station - Magnetic Heading
Bearing to station = BFM?
How can you determine how far away you are from a station and how long it will take you to get there given airspeed, degrees in bearing change per NM to station?
Time = time in seconds between bearing / degree change
Distance = TAS × time in minutes (time between radial) / 60
How does a NOTAM list its time?
YEAR, MONTH, DAY, TIME (in zulu)
What is a NOTAMC?
A cancelling NOTAM.
What is a NOTAMR?
A replacing NOTAM.
How do you calculate the closing angle to re-intercept your track after going over half the distance?
A piston single is on a short flight from Brandon (CYBR) to St. Andrews (CYAV), a distance of 110 NM. The pilot notices after flying 80 NM that they are 8° off course and want to correct this error. What will the closing angle be to re-intercept your track in time?
Closing angle = Distance off × 60 ÷ Distance to go
What projection does a LO chart use?
Lambert conformal conic.
What does it mean when a VOR frequency or NDB channel is underlined when viewed in a LO Chart?
It means that the facility does not have voice transmission capabilities.
What information does a TACAN provide?
Provides DME distance.
What is the MOCA in mountain regions 1 & 5?
2,000ft ASL.
What is the MOCA in mountain regions 2, 3 & 4?
1,500ft ASL.
How do you calculate time to an NDB?
time (IN SECONDS) / degrees of relative bearing change = Time to NDB (minutes)
How do you calculate distance to NDB?
(Groundspeed × time to NDB (IN MINUTES)) / 60 = Distance to NDB (NM)
How do you calculate range to a VHF facility?
Range = (1.25 × √indicated altitude) + (1.25 × √altitude of station)
What is the required accuracy when testing your VOR instrument using the dual VOR test?
+/- 4 degrees.
What is the required accuracy when testing your VOR instrument using he airborne geographical location check?
+/- 6 degrees.
What does “Y” mean when entered as a flight rule in a flight plan/itinerary?
IFR flight first, then VFR.
What does “Z” mean when entered as a flight rule in a flight plan/itinerary?
VFR flight first, then IFR.
What does “SD/C” mean when it is entered on a flight plan?
S - Standard equipment; one of each: VHF, RTF, VOR, ILS (VAVI)
D - DME
C - LORAN C (mode A and C capable)
What does “SFG/C” mean when it is entered on a flight plan?
S - Standard equipment (VHF, ADF, VOR, ILS) (VAVI)
F - ADF
G - GNSS
C - LORAN C (mode A and C capable)
What is magnetic deviation?
It is the difference between magnetic heading and compass heading.
One of the causes if drift in heading indicators is due to bearing imperfections. Even with prefect bearings however a heading indicator will drift because of:
Rotation of the earth while the gyroscopic axis remains fixed in place.
What is the maximum deviation a VOR CDI can display?
The maximum deviation a VOR CDI can display is +/- 10 degrees, and it is 2 degrees per dot.
LORAN works in the ____ frequency range.
Low (LF) range.
In order to get a position fix using LORAN, at least __ stations are required.
3 total stations!
A master then two secondary stations.
What is the 1 in 60 formula?
Distance off track
——————————– × 60 = track error!
Distance along track
DME operates in the _____ range and utilizes the principles of _____.
DME operates in the UHF range and utilizes the principles of secondary radar.
The angular difference between the aircraft heading and the magnetic track to an NDB station is called _______?
Relative bearing!
NDBs operate in the ___ and ____ frequency ranges which corresponds to ___.
LF and MF …
Omega and VLF are:
Very long range navigation systems requiring more than one station to determine position.
What are the six components, in their proper pairs for each vector, of the triangle of velocities?
- Wind speed and direction
- Heading and true airspeed
- Aircraft track and ground speed
Are MOCAs & MEAs on a LO chart given in AGL or ASL?
ASL!!!
What is the tolerance for a VOT check in the air vs the ground?
In the air: +/- 6 degrees
On ground: +/- 4 degrees
What is MOCA?
Minimum Obstacle Clearance Altitude.
The required clearance, NOT the elevation figure!!!!
What is MEA?
Minimum altitude to get a navigation signal. ALWAYS above MOCA.
Radar system uses what to interrogate a transponder?
Uses secondary surveillance radar.
What is the Atlantic standard time zone meridian?
60° West.
What is the Eastern standard time zone meridian?
75° West.
What is the Central standard time zone meridian?
90° West.
What is the Mountain standard time zone meridian?
105° West.
What is the Pacific standard time zone meridian?
120° West.
NDB errors:
- Night effect (remember LF/MF “sun up freq up”)
- Mountain effect
- Quadrantal/banking error
- Coastal effect (over the sea, water bends the NDB signal)
- Electrical storms
- Icing and sleet
- Precipitation static
What is differential GNSS?
It requires a ground based GPS/GNSS station in a known position to augment the satellites.
DIFFERENTIAL GPS/GNSS = 1 ground-based
What happens to your ADF when you have station passage over an NDB?
The ADF needle will swing 90 degrees and stay there.
What do the large numbers on a LO Chart represent?
Area Minimum Altitude.
A rhumb line is:
A line that meets all meridians at the same angle on a transverse Mercator projection.
Calibrated airspeed is airspeed corrected for:
Instrument and position errors.
I C E T
P C D
True airspeed is calibrated airspeed corrected for:
Density error.
I C E T
P C D
An LF/MF airway in uncontrolled airspace is identified by:
Two letters & a number.
What is relative bearing?
is the difference between magnetic heading and bearing to NDB.
Why does your heading indicator need to be adjusted at frequent intervals?
Because the earth rotates, and imperfect balancing of the gyro.
