Pilot Navigation Flashcards
Use of Aeronautical Charts
● When operating VFR OTT, night VFR, or IFR, the aircraft must have all necessary charts and publications for the route flown, including any probable diversionary route; the charts and publications must be current.
➢ 1 minute of latitude equals 1 NM
Measurement of Track
● True Track or True Course (TC) is the number of degrees between the direction of flight and True North as measured clockwise from a Longitude Line.
● If the direction of flight is from B to A (westwards) then read the True Course in degrees on the inner protractor scale (243°).
● NOTE WELL
➢ When the True Course (TC) is toward the east use the outer scale.
➢ When the TC is toward thewest use the inner scale
Methods of Departing
● There are three main ways to depart on a cross country:
➢ Overhead Departure
➢ Set Heading Method
➢ Direct Method
Set Heading Point Method
● The Set Heading Point is a point other than the airport used to depart on a cross country.
● A set heading point is used because we cannot always predict the traffic and active runways.
➢ It also gives us the time and distance we may need to get completely organized.
● This point should be along the track within 15 miles of departure.
Overhead Method
● In this case the pilot climbs to cruise altitude while circling over the departure aerodrome.
● They would then cross over the aerodrome and then set the the appropriate heading
Direct Method
● In this case the pilot turns to the heading and goes.
➢ This is the preferred departure method for Commercial licence candidates.
● This is also the method that you should assume for all of the calculations on your WRITTEN exam
Using Position Lines to Obtain a Fix
● Your heading indicator can be used to find a position relative to other landmarks.
● Visualize drawing a line through the center of the heading indicator to the landmark(s).
● Next, draw these heading lines on a map from the checkpoint(s).
● Where these lines cross is your position
Ground Speed Checks and E.T.A. Revisions
● Before takeoff the pilot should find two prominent checkpoints and measure the distance between them.
● While in flight use a stopwatch to get the time between the two checkpoints－be sure to use the minutes and seconds to be as accurate as possible.
● Divide the distance by the time to get a revised ground speed.
● Use the ground speed to calculate your remaining time
Variation and Deviation
● Variation is the difference between true north and magnetic north.
● Deviation is the compass error caused by the aircraft.
➢ This is found on the compass card mounted in the aircraft and in aircraft Journey Logbook.
➢ Applying deviation to the magnetic track gives the compass track.
True Track and Magnetic Track
● True track is the line measured on the map in relation to True North.
● Magnetic track is the line measured on the map corrected for variation in relation to magnetic north
True / Magnetic / Compass Headings
● On a Nav Log always start with the True Track and then apply the forecasted winds.
● After getting the wind corrected course (True Heading) apply the Variation to obtain the Magnetic Heading.
● Finally apply the Compass Deviation to the magnetic heading and get the Compass Heading
● If you were using an Airway, a Low Chart, or a High Chart for navigation, then you would need to convert the winds to magnetic.
● We need to do this since we are working with a magnetic track
Determining Drift with the 10° Drift Lines
● It is also a good idea to draw two lines from both the point of departure and the destination at a 10º angle on either side of the track
Drawing the 10° Lines
● These are known as 10° Drift Lines and they can help us get back on course.
● There are three methods of using the drift lines to get back on track:
➢ Visual Alteration Method;
➢ Double Track Error Method;
➢ Open and Closing Angles.
Getting Back on Track－ Visual Alteration Method
● After identifying the off-course position (and noting the number of degrees that you have drifted) fly yourself to a position back on the track.
➢ Usually we will use a prominent landmark on the track and fly to it.
● Once back on track apply a correction into the wind by the same amount as the drift error.
➢ This will prevent any further drift!
Getting Back on Track－ Double Track Error Method
● Using the 10° drift lines:
1. Note off-course position and the time flown.
2. Determine the drift angle－opening angle.
3. Double the drift angle, steer this amount towards the track for the same amount of time it took to reach the off-course position.
4. To maintain track adjust your originally-flown heading by the amount of the drift angle experienced.
● For example if the original course you were steering resulted in 5° right drift, then once back on track, you need to alter your original heading by 5° to the left. The simplest way to figure this, however, is simply to take out half of the correction you applied to get back on track.
NOTE: This method can only be used when the off-course position is noted and corrected before the mid point of track
