Navigation Principles Flashcards
Every path taken by wind or an aircraft has 2 components, which are
- SPEED
- DIRECTION
Triangle of Velocities
Angle “A” on a drawn out navigation track from point A to B is known as what
WIND CORRECTION ANGLE
What is the following definition
TMG
TRACK MADE GOOD
Actual track of the aircraft across the ground
What is the following definition (in terms of direction)
RT
REQUIRED TRACK
Required path of the aircraft across the ground
What is the following definition (in terms of direction)
H
HEADING
Direction the aircraft is heading in
Not necessarilly the direction the aircraft is travelling in
The difference between TMG and RT is known as what
TMG - Track Made Good
RT - Required Track
TRACK ERROR
The difference between track across the ground and heading is known as what
RT - Required Track
H - Heading
DRIFT
Speed, Distance, Time
If travelling at 60 kts, how much distance will be covered and in how long
60nm
1 hour
1nm in 1 minute
What does the following abbreviation stand for
ETD
ESTIMATED TIME of DEPARTURE
What does the following abbreviation stand for
ETA
ESTIMATED TIME of ARRIVAL
What does the following abbreviation stand for
EET
ESTIMATED ELAPSTED TIME
Time taken to get somewhere, measured in hours and minutes.
Expressed HHMM
0120 = 1 hour 20 minutes
What does the following abbreviation stand for
ETE
ESTIMATED TIME EN-ROUTE
Time taken between waypoint (or depature and destination)
Measured in hours and minutes
Expressed HHMM
0120 = 1 hour 20 minutes
What does the following abbreviation stand for
ATD
ACTUAL TIME of DEPARTURE
What does the following abbreviation stand for
ATA
ACTUAL TIME of ARRIVAL
An aircraft takes off from an airfield with an elevation of 1000ft. It travels at IAS 75kts with a rate of climb of 500fpm. There is a 20kt tailwind component. What altitude can be expected after a distance of 5nm?
Use a wizz wheel
2,575 ft
- IAS 75kts + 20 kts tailwind ∝ 75 + 20 = 95 kts
- Set 95 kts on the wizz wheel and determine how many minutes to travel 5nm
- Reads 3.15 minutes
- Airfract is ascending 500fpm ∝ 500 x 3.15 = 1575
- Aircraft will climb 1,575ft over 5nm. HOWEVER, we started at an elevation of 1000 ft
- 1000 + 1575 = 2575 ft
Triangle of Velocities
Find the wind velocity from the given set of values
Required Track = 100॰
Heading = 125॰
Groundspeed = 125 kts
TAS = 90 kts
Use a wizz wheel
Wind Direction 238॰
58 kts
- Set wizz wheel track tru to heading 125॰
- Move slider so center dot is set to the TAS of 90 kts
- Track true is 100॰, which is -25॰ from heading of 125॰ (125 - 100 = 25)
- Reading up the slider bar starting from the ground speed of 125 kts, read along the graph line less 25॰ i.e. follow the line to the LEFT (since we are minus) 25 degrees
- Rotate the wizz wheel until the wind dot is directly down from the center dot. You may need to adjust the slider so the dot sits on a graph line
- Deduct the value of whatever the wind dot sits on from the center dot i.e. if the wind dot sits on 42, and the center dot on 100, 100 - 42
- ANSWER = 58 kts, 238॰
LINK HERE
How long will it take to fly a track given the following set of values;
TAS = 90 kts
Track True = 100॰
Distance = 20nm
Wind Direction = 030॰
Wind Speed = 25 kts
Use a wizz wheel
15.6 min
- Set speed dot to 90 kts TAS
- Set track true to wind direction of 030॰ and mark a dot down 25 kts
- Spin the wheel to 100॰ track true, note the dot you marked moves to the right 17॰
- Remember EAST is LEAST, WEST is BEST. Since the dot moved to the EAST we subtract 17॰ from the track true. 100 - 17 = 83॰
- Move the wizz wheel so track is now 83॰. Read along the graph line where the marked dot now sits. Note it is 77 kts
- On the flight computer, set 77 kts as ground speed and set marker line to 20nm. Read the minutes from the inner wheel, note it is 15.6
The difference between Track Made Good and Required Track
TRACK ERROR
The difference between Required Track and Heading
DRIFT
