maintaining the course
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Well quite. It depends where you live - talking about how many miles off to one side you are after 30 miles flying might be all very well in Australia or the USA but there are very few places you can go that far in a straight line in the south of England!
DR 1:60
I have attached a full explanation of the 1:60 rule as a pdf. I'm sorry if this is cumbersome, I don't know of a simpler way.
If you were to use this method it requires repeating for a closing angle to the next waypoint or destination if that is the choice. Otherwise using the discovered angle off track double it toward the track to regain in the same distance and time or treble it to regain track in half the distance and time.
As can only be expected there are various 1:60 methods such as using inverse fractions, particular used by commercial pilot schools, for a number of years, who preferred closing angle direct to destination/waypoint for reasons that do not bear explanation.
If you were to use this method it requires repeating for a closing angle to the next waypoint or destination if that is the choice. Otherwise using the discovered angle off track double it toward the track to regain in the same distance and time or treble it to regain track in half the distance and time.
As can only be expected there are various 1:60 methods such as using inverse fractions, particular used by commercial pilot schools, for a number of years, who preferred closing angle direct to destination/waypoint for reasons that do not bear explanation.
Last edited by Fl1ingfrog; 4th Feb 2018 at 23:59. Reason: improved pdf
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A lot of information here, but it seems that the common message is that I am doing it wrong with 'feature crawling'. My question then is how can one fly a calculated heading without constantly looking at the instruments.
Of course, when I select feature ahead of me, it is just for the reference to keep me within a few degrees of the heading until the next checkpoint. Am I expected to fly in the straight line? I severly doubt my ability there.
What is my instructor telling me? well ....
Our club operates with a different instructor on each day of the week, and therefore I have now flown with almost every instructor. I don't like it but I don't have much choice there. I reckon my difficulties are partly due to every instructor teaching the same thing slightly different.
Of course, when I select feature ahead of me, it is just for the reference to keep me within a few degrees of the heading until the next checkpoint. Am I expected to fly in the straight line? I severly doubt my ability there.
What is my instructor telling me? well ....
Our club operates with a different instructor on each day of the week, and therefore I have now flown with almost every instructor. I don't like it but I don't have much choice there. I reckon my difficulties are partly due to every instructor teaching the same thing slightly different.
Last edited by indyaachen; 5th Feb 2018 at 09:59.
DR Nav
indyaachen
The earth is the best and most reliable instrument, it doesn't suffer from precession nor topple.
Having set heading and noted the time; check/adjust the HI against the wet compass then select a good reference feature, well ahead, as close as possible to the horizon. Revise the heading if necessary. The reference doesn't need to be on the nose, to one side will do but keep the relationship constant. You can even use a cloud or cloud formation, it won't change much in the short time you will be using it. Complete your FREDA/LIFE checks or whatever you have been taught.
As you get closer to your reference you will need to revise it. During this time relax, if you maintain wings level and fly in balance then your heading will remain constant and height maintenance will be good. You do not have to constantly stare at the HI. The more you roll or yaw the more you will cause precession of the HI. Not only for safety, though important, having your head up and looking out you will naturally maintain spacial awareness. As light changes so does the look of the world around you which can be confusing. So often the pilot believes they are lost because of this phenomena and air traffic confirm they are exactly where they expect to be.
DR navigation is not about flying in straight lines (although nice if it happens) but rather about flying a constant heading and speed. At intervals, I would suggest never less than 8-10 minutes, calculate any off track and time errors, you have now found the actual w/v. Regain track, check you HI against the wet compass and having done so revise your heading by the value of the track error.
Any club that allows instructors to do their own thing is unacceptable and I have never allowed it. Particularly in a situation where the student must fly with a range of instructors during their training.
The earth is the best and most reliable instrument, it doesn't suffer from precession nor topple.
Having set heading and noted the time; check/adjust the HI against the wet compass then select a good reference feature, well ahead, as close as possible to the horizon. Revise the heading if necessary. The reference doesn't need to be on the nose, to one side will do but keep the relationship constant. You can even use a cloud or cloud formation, it won't change much in the short time you will be using it. Complete your FREDA/LIFE checks or whatever you have been taught.
As you get closer to your reference you will need to revise it. During this time relax, if you maintain wings level and fly in balance then your heading will remain constant and height maintenance will be good. You do not have to constantly stare at the HI. The more you roll or yaw the more you will cause precession of the HI. Not only for safety, though important, having your head up and looking out you will naturally maintain spacial awareness. As light changes so does the look of the world around you which can be confusing. So often the pilot believes they are lost because of this phenomena and air traffic confirm they are exactly where they expect to be.
DR navigation is not about flying in straight lines (although nice if it happens) but rather about flying a constant heading and speed. At intervals, I would suggest never less than 8-10 minutes, calculate any off track and time errors, you have now found the actual w/v. Regain track, check you HI against the wet compass and having done so revise your heading by the value of the track error.
Any club that allows instructors to do their own thing is unacceptable and I have never allowed it. Particularly in a situation where the student must fly with a range of instructors during their training.
Having been the Navigator in a Rally Car, I soon got to realise that where the bonnet was pointing was not necessarily the direction we were traveling... The old joke was that you cleaned the side windows so that you could see where you were going.
It is exactly the same with flying in a crosswind. If you have 10 degrees of drift, then you are not going where the prop-spinner is pointing... More likely it coincides with the pillar on the left, or the edge of the bonnet to the right. So look for landmarks in either of those directions to aim at, and fly over.
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It is exactly the same with flying in a crosswind. If you have 10 degrees of drift, then you are not going where the prop-spinner is pointing... More likely it coincides with the pillar on the left, or the edge of the bonnet to the right. So look for landmarks in either of those directions to aim at, and fly over.
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Most pilots, even PPLs these days (due to GPS etc), don't navigate enough with compass, stopwatch and map to realise that with a bit of experience it's uncanny how accurately you can do it.
I used to regularly fly hundreds of kilometers over featureless African bush and swamp with the GPS switched off for the practice. I was struck by two things:
(a) With practice you quickly 'sense' after setting course how much drift you have and how much to correct by. After flying regularly like this for a bit you get an intuition for it; no need for fancy mental calculations.
(b) If you fly the same route enough, even if it is featureless, you know where you are simply by such things as slight changes in the colour of the ground etc.
However, technological aids (which I am all for by the way) mean people rarely fly enough the old fashioned way to get really good at it.
Golden rule of course - stick to your heading like glue unless youhave reason to change it.
I used to regularly fly hundreds of kilometers over featureless African bush and swamp with the GPS switched off for the practice. I was struck by two things:
(a) With practice you quickly 'sense' after setting course how much drift you have and how much to correct by. After flying regularly like this for a bit you get an intuition for it; no need for fancy mental calculations.
(b) If you fly the same route enough, even if it is featureless, you know where you are simply by such things as slight changes in the colour of the ground etc.
However, technological aids (which I am all for by the way) mean people rarely fly enough the old fashioned way to get really good at it.
Golden rule of course - stick to your heading like glue unless youhave reason to change it.
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Then there's the "how to find a clearing in the Burmese jungle" game, when the weather forecasting is sufficient to tell you whether the wind is coming from the left or the right but not how strong it is accurately enough for you to end up over a tiny clearing in a vast jungle. And having done your dead reckoning and not seeing the clearing, do you turn left or right? - you haven't a clue.
Instead, fly desired track for heading, for the calculated time. You then know you're downwind of the destination, so turn 90 degrees upwind and fly until you spot it.
Instead, fly desired track for heading, for the calculated time. You then know you're downwind of the destination, so turn 90 degrees upwind and fly until you spot it.
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The Sir Francis Chichester method. Yes it works. It's also a good navigation technique for finding your way on land - the army teach it, and orienteering people use it.
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(PS: shouldn't need saying, but these days ...
DON'T TRY THIS AT HOME CHILDREN
Not if you're within a couple of hundred miles of controlled air space, anyway.)
DON'T TRY THIS AT HOME CHILDREN
Not if you're within a couple of hundred miles of controlled air space, anyway.)
