En-Route Navigation: Techniques Flashcards
Dead reckoning is otherwise known as what?
Deduced reckoning
Three steps of dead reckoning?
Starting at known position
Measuring track and distance to the next fix
Applying best wind estimate to make track good
What can be used to evaluate the success of dead reckoning?
Map-reading
A fix without radio navigation equipment is called a what?
Pinpoint
What is track error?
Difference between desired track and the actual track made good
The difference between desired track and the actual TMG is called?
Track error
A groundspeed of 85kt is roughly equivalent to …nm per minute?
1.5nm
A groundspeed of 85kt will cover roughly what distance in 5 minutes?
7 miles
At 5000ft, TAS is approximately how much greater than IAS?
8%
During the cruise, what is the best method to checking your groundspeed (in line with your pre-flight calculated GS)?
Between two fixes at a set distance apart, use the time between to calculate the groundspeed
What’s the reason behind keeping a line feature to your left if following it en-route?
It is easiest to see out of the captain’s seat
What is a position line?
Extended straight line joining two points, of which the aircraft is somewhere between
Why is a position line not as specific as a fix?
A fix is a specific point, whereas a position line is a position along a line
Position lines can sometimes be known as what?
Line of position
How could you use position lines to obtain a fix?
The lines’ point of intersection can act as a fix
If flying between checkpoints 10 or 15 minutes behind at GS of 85kt, how far apart are they?
14nm or 21nm
Major principle of navigation with a chart?
Read from chart to ground
Reading from a chart to the ground involves what?
From the chart select a suitable feature ahead of present position
Calculate an ETA
A few minutes before the ETA, lookout for the actual feature
What should be logged on your chart, as opposed to the PLOG?
Fixes and TMG
When lost, how should you navigate in general terms?
Read from ground to chart
Reading from ground to chart should be done when?
Lost
How do you estimate the ‘most probable area’ when lost?
Estimate distance flown since the last fix
Apply this distance, +/- 10%, to an arc 30 degrees either side of the estimated TMG
What should you establish asap once a ‘Most Probable Area’ is calculated when lost?
Safety altitude
What consideration must be made when flying during the evening?
It will get darker at ground level than at altitude
Gyro corrections should be done how often?
10 or 15 minutes
Compared to track, heading should always be pointing…
Into wind
What will ALWAYS be closer to into-wind? Track or Heading?
Heading
TAS 90kts, Max Drift is equal to
2/3 of wind speed
A Max Drift equal to 2/3 of wind speed occurs at what speed?
90kts TAS
ETA adjustment formula
Minutes fast/slow x 1/Proportion of leg flown
If 5 minutes fast halfway along a leg, what should you do to your ETA?
Subtract 10 mins from ETA
1 thumb on chart roughly equates what time in nil wind?
6 minutes
30 degree off track = what drift?
1/2 of Max Drift
45 degree off track = what drift?
3/4 of Max Drift
60 degree off track = what drift?
Whole of Max Drift
1/2 of max drift experienced means the wind lies at what angle from track?
30 degrees
3/4 of max drift experienced means the wind lies at what angle from track?
45 degrees
Whole of max drift experienced means the wind lies at what angle from track?
60 degrees
