Drift Lines
Thread Starter
Joined: Jun 2010
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From: London
Drift Lines
What is the general opinion on drawing drift lines on a chart when the legs are short <15nm ? I find they mask the features on the chart and over complicate the area you are looking at.
Fleet Manager
Joined: Aug 2006
Aviation Qualifications: CPL
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From: Ontario, Canada
My opinion is:
1) Follow the requirements of your instructor, examiner, and the aircraft owner.
I have drawn drift lines on charts on the following occasions: During grounschool, whem it was being taught, for practice cross country flights with the instructor, and for flight tests.
2) For me, other than that, not so much....
1) Follow the requirements of your instructor, examiner, and the aircraft owner.
I have drawn drift lines on charts on the following occasions: During grounschool, whem it was being taught, for practice cross country flights with the instructor, and for flight tests.
2) For me, other than that, not so much....
Joined: May 2008
Posts: 1,366
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From: UK
I would draw one reference line at 10 degrees to about halfway along the track. This will give you something to judge how far off track you are, if it's the side you didn't draw the line you can still judge it from one line.
Drawing four fan lines in a kite shape is rather excessive, but I see a lot of other instructors teaching to do this for every single leg. In my experience, one line is enough for any leg and just gives a reference to make a calculated correction. Otherwise, come test you're left saying "I'm off track, so will turn 10 degrees to the left" and if the examiner quizzes you on where that figure came from it seems rather plucked from the air. It is better to have a method to fall back on at least for test, then you can do whatever you want once you pass.
Drawing four fan lines in a kite shape is rather excessive, but I see a lot of other instructors teaching to do this for every single leg. In my experience, one line is enough for any leg and just gives a reference to make a calculated correction. Otherwise, come test you're left saying "I'm off track, so will turn 10 degrees to the left" and if the examiner quizzes you on where that figure came from it seems rather plucked from the air. It is better to have a method to fall back on at least for test, then you can do whatever you want once you pass.
Joined: Aug 2003
Posts: 240
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From: Scotland
Tomboo,
You should not normally need to put drift lines on a leg of less than 15 nm. As a simple practical matter, on a leg of less than 15 miles you should pretty much be able to see your next turning point before you set off; since you can see the turning point you can very quickly determine and correct the drift by "eye".
Drift lines are useful on long sectors where the end point is too far to see, and therefore you need an interim "how goes it" in order to update your heading. Even so, they are not widely used - you'll get better at map reading with practice, and although they may actually be doing more or less the same adjustments, with better situational awareness most pilots do it without drawing drift lines.
As others have noted, an examiner on a test MAY ask you to demonstrate a drift line technique on a very short sector, but that's only becase he doesn't feel like sitting there while you fly a 100 nm sector!
You should not normally need to put drift lines on a leg of less than 15 nm. As a simple practical matter, on a leg of less than 15 miles you should pretty much be able to see your next turning point before you set off; since you can see the turning point you can very quickly determine and correct the drift by "eye".
Drift lines are useful on long sectors where the end point is too far to see, and therefore you need an interim "how goes it" in order to update your heading. Even so, they are not widely used - you'll get better at map reading with practice, and although they may actually be doing more or less the same adjustments, with better situational awareness most pilots do it without drawing drift lines.
As others have noted, an examiner on a test MAY ask you to demonstrate a drift line technique on a very short sector, but that's only becase he doesn't feel like sitting there while you fly a 100 nm sector!
Joined: Aug 2000
Posts: 1,214
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From: S Warwickshire
If you feel the need for drift lines and don't want to clutter your map, then get a strip of acetate or clear plastic and a sharpy pen and draw a pair of lines intersecting at 10 degrees.
When you have marked a position fix on your map, drop over the overlay and interpolate your track error and/or closing angle.
Alternative is to ignore them completely and use a standard closing angle technique. I know that you still want to know the track error to set the new heading required.
Better still, use a GPS and don't get off track in the first place. But that's after you finish your training
When you have marked a position fix on your map, drop over the overlay and interpolate your track error and/or closing angle.
Alternative is to ignore them completely and use a standard closing angle technique. I know that you still want to know the track error to set the new heading required.
Better still, use a GPS and don't get off track in the first place. But that's after you finish your training
