Lesson 15. Basic Navigation Flashcards
Meridians of longitude run _______.
North and south
- connect the earths poles
How many parallels of latitude are there?
1; the equator
What are the places where meridians and parallels cross called?
Coordinates
1 minute of ______ is equal to 1 nm.
latitude
1 minute of longitude is equal to 1nm only where?
At the equator
How many minutes are there in 1 degree of latitude?
60
A ________ is the shortest distance between two points on a sphere.
Great circle route
– most direct; crosses every meridian at a different angle
A _______ is a line which makes the same angle with each meridian of longitude, and is longer than a great circle route.
Rhumb line
– a/c holds a constant heading; requires more fuel and time; easier to navigate
1 NM = ___ SM
1.15 statute miles
1 SM = ___ NM
0.87 NM
Coordinated Universal Time (utc)
Local standard time at Greenwich, England
- “Zulu” time
- eliminates confusion caused by diff local times
How many time zones is the earth divided into? How wide are each?
- 24 standard time zones beginning at 0* longitude
- each zone is 15* of longitude wide starting at the prime meridian
What speed is shown on the aircrafts airspeed indicator?
Indicated airspeed (ias)
What speed is relative to u disturbed air mass and is used in flight planning and en route portion of flight?
True airspeed (tas)
Ground speed (gs)
True airspeed corrected for wind
Mach number (Mach)
Ratio of true airspeed to the speed of sound, expressed in decimal form
Parallels of latitude run ________.
East and west
Indicated airspeed _____ with ______ in altitude and temperature.
Decreases; increases
At high altitudes an aircrafts indicated airspeed is significantly ______ lower than its true airspeed.
Lower
Recall the finger formula for:
D = distance
S = speed
T = time
D
________________
S / T
_______ is a mass of air moving over the earths surface in a definite direction.
Wind
- stated in direction it is blowing from, and velocity in knots
Which does wind affect, true airspeed or ground speed?
Wind affects ground speed.
- increased by tailwind
- reduced by headwind
What does crosswind affect?
Speed and direction
________ represents the intended path of aircraft over the earths surface.
True course
_________ is the actual path that the aircraft has flown over the earths surface.
Track
Drift angle
What any free object will do as the air moves downwind with the speed of the wind
(Angle between true course and track)
________ is true course (tc) corrected for wind drift.
True heading
- TC +- WCA = TH
- controllers responsibility to compensate for wind speed and direction when formulating estimates and issuing radar vectors
________ is the angular difference between true north and magnetic north; measured in degrees from true north.
Variation
________ connect points of equal difference between true and magnetic north.
Isogonic lines
______ connects points of zero variation; only one.
Agonic line
_______ is true heading (th) corrected for variation.
Magnetic heading (mh)
TH +- VAR = MH
For East variation, ________ degrees of variation.
For West variation, ________ degrees of variation.
Subtract. ( east is least)
Add. (West is best)
Deviation
The error of a magnetic compass due to magnetic influences in the structure and equipment of the aircraft.
Results from electrical circuits, engine and other magnetized parts.
________ is the magnetic heading (mh) corrected for deviation.
Compass heading (ch)
MH +- DEV = CH
What is the full formula to get from true course (tc) to compass heading(ch)?
TC +- WCA = TH +- VAR = MH +- DEV = CH
_______ is navigation of an airplane solely by means of computations based on airspeed, course, heading, wind direction, and speed, ground speed, and elapsed time.
Dead reckoning
________ is the determination of position by identification of landmarks from their representation on a chart.
Pilotage
- useful only in VFR WEATHER
________ is a method of determining and maintaining a desired course or determining an aircrafts position by use of radio navigation aids on the ground.
Radio navigation
- all ground based
What are the advantages and disadvantages of radio navigation?
advantages:
- all weather navigation capability
- allows instrument approaches and landings at night and during bad weather
Disadvantages:
- relies on aircraft and ground equipment that is subject to malfunction and interference
__________ is a method of navigation which permits aircraft operation on any desired flight path within the coverage of ground or space based navigation aids or within the limits of the capability of self contained aids, or a combination of these
Area navigation (RNAV)
- pilot doesn’t need to fly over ground based equipment and can get a direct course using waypoints
Satellite navigation
GPS allows anyone with a proper receiver to determine his position instantaneously with near pinpoint accuracy.
How many satellites operate for GPS and what are the advantages?
24 operational satellites
Advantages:
- provides accurate info 24 hrs a day
- unaffected by the weather
