Navigation Flashcards
1
Q
what are great circles? what is an example?
A
lines that lie in a plane passing through the centre of the Earth when it is represented by a sphere
- e.g. meridians of longitude, the Equator
2
Q
what are characteristics of great circles?
A
- they are the shortest distance between any points on the surface of the Earth occurs when they are located on the arc of a great circle
- only one great circle can be drawn between two points on the surface of the Earth
3
Q
what are small circles? what is an example?
A
a line that lies in a plane that does not pass through the centre of the Earth when represented by a sphere
- e.g. parallels of latitude other than the Equator
4
Q
what are rhumb lines?
A
an imaginary line that maintains a constant angle as each successive meridian is crossed
5
Q
why are rhumb lines used?
A
the rhumb line keeps the same track (unlike a great circle), but it does cover a greater distance
6
Q
how do you speak the coordinates 54°39’N, 006°13’W?
A
54 degrees 39 minutes North, 6 degrees 13 minutes West
7
Q
what is the long name of DMS Notation?
A
degree-minute-second
8
Q
what is DMS Notation?
A
converts 54°39’42”N, 006°12’58”W to 543942N 0061258W
9
Q
convert 60°35’15” to decimal notation
A
ANSWER: 60.5875°
Steps:
- +60
- 35 ÷ 60 = 0.58333
- 15 ÷ 3,600 = 0.004167
- add them together
- round to 4 decimal places
10
Q
convert 48°28’32” to decimal notation
A
ANSWER: 48.4756°
Steps:
- +48
- 28 ÷ 60 = 0.46666…
- 32 ÷ 3600 = 0.00888888889
- add them together
- round to 4 decimals
11
Q
define drift
A
the angular difference between the track of the aircraft across the ground and its heading
12
Q
what does the preflight plan involve
A
- pilot log
- mass and balance calculations
- aircraft performance calculations
- radio frequencies of ATSUs and nav aids for en route use
- note pad for weather and clearance info
- fuel plan
- terminal info for the destination, en route alternative, destination alternative
13
Q
you are flying and maintaining a heading of 360°T and experience a 10° right drift. What is the aircraft’s true track?
A
010°
(360 + 10 = 010°)
as the aircraft nose is going clockwise, add
if it moves anticlockwise, subtract
14
Q
how do you locate 54°39’N, 006°13’W on a chart?
A
- locate the square bounded by 54°N, 55°N, 006°W and 007°W (grid ref. uses lower value)
- it’s 39 minutes north -> 39/60ths of distance towards 55°N
- it’s 13 minutes west, 12/60ths
15
Q
how many metres is 1 nautical mile?
A
1,852m
16
Q
how many statute miles is 1 nautical mile?
A
1.151 statute miles
17
Q
how many nautical miles in 1 degree of latitude (measured along a line of longitude)?
A
60nm
18
Q
how many nautical miles in 1 degree of longitude (measured along a line of latitude)?
A
only equals 60nm on the equator, decreases as you go further north/south
19
Q
an aircraft travels north along the same meridian from latitude 30°15’S to 14°00’S. what is the distance travelled in km?
A
1) 30°15’ - 14° = 16°15’
2) 16 x 60 = 960nm
3) 960 + 15 = 975nm
4) 975nm to km = 975 x 1.852
5) = 1805.7km
20
Q
what does conformal/orthorhombic mean?
A
preserves angular relationships
21
Q
what are the characteristics of Standard Mercator Projection?
A
- represents larger areas
- meridians show little convergence at the equator
- significant scale distortion can happen in mid latitudes and near the poles
22
Q
what are the characteristics of Transverse Mercator Projection?
A
- depicts smaller, detailed areas
- it is the 1:250,000 UK Aeronautical Chart
23
Q
what kind of projection is the 1:250,000 UK Aeronautical Chart?
A
Transverse Mercator Projection
24
Q
what are the characteristics of Lambert Conformal Conic Projection?
A
- shows mid-latitudes well, ideal for UK
- meridians can converge
- it is the 1:500,000 UK Aeronautical Chart
25
what earth distance, in nautical miles, is represented by a chart length of 5.2cm on a 1:250,000 aeronautical chart?
1) 250,000cm = 2.5km
2) 2.5km ÷ 1.852m = 1.35nm
3) 5.2 x 1.35 = 7.02nm
25
what kind of projection is the 1:500,000 UK Aeronautical Chart ?
Lambert Conformal Conic Projection
25
what is the formula for chart scale?
chart length / earth distance
25
what is 1nm worth?
1 minute (60 seconds, 1/60 of a degree)
25
what formula is used to calculate the distance in nm represented by a change in longitude at other parallels of latitude?
dLong x cos(Lat)
dLong = change in longitude (in minutes, so you do [degrees] x 60 = change in longitude in minutes)
26
what are the vertical limits of an ATZ?
2,000ft
26
how big is the ATZ radius if the 1,850m or less? what about greater than 1,850m?
2nm
2.5nm
27
what equipment is needed for navigation?
map, compass, timepiece, speed, altitude
28
what is the axial tilt of the earth?
23.5°
29
what is the distance travelled (in nm) between 035°W and 035°E at latitude 53°N?
1. 35 + 35 = 70°
2. 70° x 60 = 4200 minutes
3. 4200 x cos(53) = 2527.6nm
30
what are isogonals?
lines of equal magnetic variation
31
what is VAR?
Variation - the difference in bearing between true north and magnetic north
37
one nautical mile is defined as:
a change of latitude of 1 minute
38
meridians of longitude are:
lines joining the true north and true south poles
39
what is the written reference for a point half way between the equator and the True North Pole on the opposite side of the world from the Greenwich (or Prime) Meridian?
N45° 0.0' E180° 0.0' or W180° 0.0'
40
what is the ecliptic path? what is the ecliptic angle?
due to the tilt of the earth, the sun appears to track along a great circle as the year progresses at an angle to the equator
- peaks at winter and summer solstice
ANGLE: 23°27'
41
how long is a Sideral Day?
23 hours 56 minutes 4.091 seconds
42
what is the Mean Day?
an artificial unit of constant time based on the average of all apparent days in a year
43
what is the rotational speed of the Mean Sun?
15° per hour
44
what is the time to longitude relationship?
15° of longitude = 1 hour
45
what is LCM (Local Mean Time)?
when the sun is directly overhead the observer (mid-day)
46
what is LST (Local Standard Time)?
countries elect to adhere to a standard time (especially for large countries)
47
what is UTC (Universal Coordinated Time)?
the time at 0° meridian
EAST: local time in advance of UTC
WEST: local time behind UTC
48
what is the International Date Line?
where one day stops and a new one begins
anti-meridian to the Prime meridian
altered to avoid populated areas
49
At 1100UTC, what is the LMT in Moscow, Russia (N55°45' E037°36')?
ANSWER = 13:30
Step 1:
find difference in longitude from Prime Meridian
= 37°36'
Step 2:
time difference in hours - 37°36'/15 = 2.5
-> this is because there are 60 minutes in 1 degree
-> 37° x 60 = 2,220 minutes
-> 2,220 + 36 = 2,256 minutes
-> 2,256/60 = 37.6 hours
-> 37.6 / 15 (because for 1 hour of longitude = 15°) = 2.5 hours
Step 3:
Moscow is AHEAD of UTC by 2.5 hours - 1100UTC + 2.5 hours = 1330LMT = 13:30
50
what is conformity?
directions are accurate
51
what is equivalence?
scale of the map is correct
52
what are the standard parallels of lambert conformal conic projection?
the only latitudes where conformance is accurate
53
what shape is lambert conformal conic projection?
conic
lol
54
what shape is direct mercator projection?
vertical tube (see notes)
55
how to measure the length of a line on a chart?
transpose the length of the line you want to measure onto a longitude to measure its distance
56
one minute of change in latitude equals:
1 nautical mile
57
bearing is measured in relation to:
true north
58
what is bearing?
measurement of direction
59
how do the meridians converge in Lambert Conformal Conic Projection?
- meridians of longitude converge at top of map
60
where do you measure bearing from?
always measure the bearing of the track at the centre point (middle) of that track
61
what do you do when variation is east? what abt west?
west is best - add
east is least - subtract
62
thumb equals:
5nm
63
how many ft is 1nm?
6080ft
64
When measuring a track angle on a Lambert Conformal Conic chart, why is it important to measure at the centre of a track line?
so the average true track angle is observed
65
A straight line on a Lambert Conformal Conic chart practically represents a Rhumb line. True or False?
false
66
what airspace does the 1:500,000 chart show?
all airspace under FL195
67
what airspace does the 1:250,000 show?
all airspace under FL55 and 5000ft amsl
68
no elevation is shown unless it reaches 500ft or more. true or false?
true
69
no obstruction is shown unless it is 328ft above sea level. true or false?
true - remember 328ft
70
how many figures are shown against tall obstructions?
2 - one for height AMSL, one for height above ground level AGL
71
what is MEF?
Maximum Elevation Figure - the higher of the tallest obstacle
- marked on each 30 min lat/long grid (whole grid)
-rounded to next 100ft
72
how are danger areas signified?
with a D
- some danger areas have a * prefix, which means it is prohibited by law to enter
- some have a DACS (Danger Area Crossing Service) and a DAAIS (Danger Area Activation Information Service)
73
how are restricted areas signified?
with an R
- restricted in accordance with certain conditions (maybe type of aircraft)
74
how are prohibited areas signified?
with a P
75
what are the 4 chart features?
1. HIRTA (High Intensity Radio Transmission Areas)
2. GVS (Gas Venting Station)
3. Navigation Aids
4. Instrument Approach
76
what are HIRTAs?
High Intensity Radio Transmission Areas
- can be dangerous to aircraft equipment and pilot health
77
what are GVSs?
Gas Venting Stations
- vents gas at high pressure into the atmosphere above
78
what are Navigational Aids?
- identities and frequencies shown on the chart
- VOR (VHF - frequencies in MHz), hexagon
- NDB (MF/LF - frequencies in kHz), circle
79
what is instrument approach?
if an airfield has an instrument approach that is outside of controlled airspace, this is signified on the chart by 'arrow fans'
80
On a chart, what would the following area signify: D208/2.0 OCNL 65.0?
A Danger Area. 208 is the identity of the danger area. Normally active from the surface to altitude 2,000ft, occasionally from the surface to altitude 65,000ft
81
What is a "Transponder Mandatory Zone" (and the rules of entry according to SERA), and how is it marked on an aviation 1:500,000 chart?
An area where a working Mode C or Mode S transponder is mandatory for transit (without radio contact with the associated ATSU), or, if the aircraft is not Mode C or Mode S transponder equipped, a transit clearance is required from the associated ATSU. Marked by light pink semi-circles around the airspace outline
82
Gliding sites have a number written against their chart symbol. What does this figure refer to?
The altitude (height above mean sea level) up to which cables may be used to launch gliders
83
On a chart, a red circle annotated with GVS2.7 stands for what?
Gas Venting Station up to altitude 2,700 feet above mean sea level
84
height vs altitude:
ALTITUDE: Refers to the vertical distance of an aircraft or object above mean sea level (MSL)
HEIGHT: Refers to the vertical distance of an aircraft or object above a specific point, such as the ground, a runway, or a building.
85
Info on TMZs:
read through
A TMZ is a Transponder Mandatory Zone.
Effectively, an aircraft may fly in a TMZ without obtaining a clearance to do so, providing it has a serviceable transponder with Mode A and Mode C (altitude reporting) capability, or Mode S, and is operational in these modes whilst within the TMZ.
For aircraft without a transponder, or for those aircraft that only have a Mode A transponder (i.e. no altitude reporting), they must FIRST gain a clearance to enter the TMZ via Radio Communications (RTF). If no clearance is sought, or given, that aircraft may not enter a TMZ.
The requirements above are as laid down by SERA (Standard European Rules of the Air). In the UK, the AIP also states that for any TMZ, the requirements is Mode S. In other words, if you only have Mode A+C, you will still need permission to enter the TMZ.
The TMZ is marked on the chart in question as shown in the diagram below.
86
what is a CTR?
control zone
87
which airspaces are uncontrolled?
G and F
88
what is track error?
the angular difference between the required track and the track made
89
what is VOR?
VOR is a ground-based radio navigation system that uses very high frequency (VHF) radio waves to provide pilots with bearing information (radials) to or from the VOR station
90
what is NDB?
An NDB is a radio beacon that emits a signal in all directions, allowing pilots to determine their bearing (direction) to the beacon using an ADF (Automatic Direction Finder)
91
what is the difference between VOR and NDB?
NDBs are non-directional, providing only a bearing to the beacon, while VORs are omnidirectional, providing 360 degrees of course guidance
92
How is terrain depicted on an aviation 1:500,000 chart?
By colour and spot heights marked in black
93
What is an MEF figure?
Maximum Elevation Figure. The height of the highest obstacle above ground level, rounded up to the next 100ft for that 30' segment of latitude and longitude
94
what is TMG?
Track Made Good - the actual track of the aircraft across ground
95
what is RT?
Required Track - the required track of the aircraft across ground
- difference between TMG and R is track error
96
what is heading?
the direction the aircraft is heading in (but not necessarily travelling in)
- difference between RT and H is drift
97
formula for speed?
speed = distance/time
98
what units of time are used?
hours
99
what are some abbreviations for time and what they stand for?
ETD (Estimated Time of Departure), ETA, EET (Estimated Elapsed Time), ETE (Estimated Time En-route), ATD (Actual Time of Departure), ATA (Actual Time of Arrival)
100
is height set to QFE or QNH?
QFE
101
is altitude set to QFE or QNH?
QNH
102
what is FL set to on the altimeter?
1013
103
why use FL setting and not QNH?
QNH varies across small geographic areas, so aircraft can't guarantee height separation
104
what is QNE?
a height - that of an aerodrome threshold when the altimeter is set to SPS (1013.2hPa)
-> used for aerodromes that are at a high altitude because setting QFE is impossible
105
what is the transition altitude in the UK? (figure)
3,000ft
106
what is transition level?
the lowest available flight level above transition altitude
107
what is transition layer?
the layer of air between transition altitude and transition level
108
what does ASR stand for?
Altimeter Setting Regions
109
what happens when flying from high to low pressure?
the altimeter will be over-read i.e. you will be lower than the altimeter reading
110
what is RPS?
Regional Pressure Setting
111
what do ASRs provide?
the pressure setting that is the lowest forecast setting for the next 2 hours
(Updated every 1 hour)
112
what are the calibrations of an altimeter?
1. 15 degrees C at sea level
2. lapse rate of 2 degrees per 1,000ft
3. density of 1.225 something /m^3
113
what does ISA stand for?
International Standard Atmosphere
114
when flying from high to low temperature, the altimeter will over-read. true or false?
true
115
what factors can affect airspeed?
(hint: 6)
1. instrument errors
2. position error (maybe with pitot heat)
3. IAS and CAS
IAS - speed indicated in the cockpit by ASI
CAS - IAS corrected for instrument and position errors
4. environmental error - where ISA conditions are not present
116
how does deviation affect bearing?
compass deviation:
- aircraft themselves have an impact on their magnetic compass
- they have a 'compass swing' that calibrates the ASI as best as possible
- remaining minor erros are listen on the 'Compass Deviation Card'
- the magnetic heading provided by compass needs to have Deviation to be accurate
117
what is compass dip error?
when the aircraft banks, the needle of the compass will try and follow the isogonal (e.g. swing towards the surface) which is magnetic north. most extreme effects are on northerly and southerly headings
118
what does UNOS stand for?
Undershoot North - roll out before compass reaches North
Overshoot South - roll out after compass reaches South
119
what is compass acceleration error (use example of an Easterly heading)? what is ANDS?
on an Easterly heading - aircraft accelerates, compass swings towards us (indicating a turn to the North)
on an Easterly heading - aircraft decelerates, compass swings away from us (indicating a turn to the South)
ANDS - Accelerate North, Decelerate South
120
what does TVMDC (AW) stand for?
True heading
Variation
Magnetic heading
Deviation
Compass heading
(Add West)
True Virgins Make Dull Companions (At Weddings)
NOTE: T + V = M + D = C
121
define night (ICAO)
the hours between the end of the evening civil twilight and the beginning of morning civil twilight
122
define civil twilight (ICAO)
it ends in the evening when centre of the sun's disc is 6° below horizon
OR
it begins in the morning when the centre of the sun's disc is 6° below horizon
(basically the time between sunset and total darkness, which happens when the sun is 6° below horizon AND the time between the end of total darkness, below 6° on horizon, and sunrise)
123
what is specific gravity?
how dense the fuel is
124
how many US gallons is 1 imperial gallon?
1.2 US gallons
125
how many litres is 1 imperial gallon?
4.5 litres
126
what is the specific gravity of AVGAS?
0.72
127
what is MAUW?
Maximum All Up Weight (or sometimes Mass)
- maximum weight allowed for the aircraft
128
what is the payload?
load carrying capacity (including passengers, cargo and baggage)
- don't include pilot, crew and fuel
129
payload = ?
payload = MAUW - total weight
130
Calibrated Airspeed is the indicated airspeed corrected for which two factors?
position and instrument
131
When flying VFR under SERA rules (no UK CAA exemption) on an altimeter setting of 1013 hPa above a Transition Altitude of 3,000 ft, Magnetic Heading 274o, which is compensating for 5o drift TO the left, what recommended FL should be flown if Class A airspace above starts at FL60?
FL45
132
Which of the following best explains "Dip Error" associated with a compass?
When an aircraft banks, the magnetic needle end will swing towards the earths surface towards magnetic north. Largest error will occur on Northerly or Southerly headings.
133
Calculate your true altitude given that:
Indicated altitude: 6,200 ft
QNH: 1030 hPa
Calibrated outside air temperature: 10oC
Assume 1hPa = 30ft
6,340 ft
134
Assuming an aircraft is using runway 02, what would the cross-wind component be if the wind was 050o 18kt?
9kt from the right
135
What is the magnetic heading and groundspeed given that; Track 195oT, TAS 110kt, Wind 305o 38kt, VAR 2oW?
215 degrees, 118kt
136
What is the weight of fuel in kg (with a specific gravity of 0.72) required for a trip of 180nm at a groundspeed of 90kt, given that the fuel burn of the aircraft is 20 US Gallons per hour?
109kg
137
What is a NOTAM?
Notification of information important for aviation that must be checked before every flight
138
Where is the official source of information for NOTAMS?
UK NATS AIS system (free access)
139
what is the 1:60 rule?
for each 1 degree of track error, the aircraft will be 1nm off track after 60nm
140
formula for track error:
distance off track (nm)/distance gone (nm) x 60 = track error
141
formula for closing angle:
distance off track/distance to go x 60 = closing angle
142
how to amend heading?
track error + closing angle = alter heading by this amount
143
what is maximum wind correction angle (WCA)?
max. WCA = 60 / TAS x wind speed
