1:60 rule

[KandiFloss]

Hi ppruners,

Does anyone have any easy methods/techniques for the 1:60 rule? Even now i'm still struggling to get my head around it. I understand about using 'fan-lines' to determine how far you are off track, and to get back on track you have to double your 'off-track' angle. But I know that this depends upon how far you are along the 60 mile section. An instructor siad that if you're a quarter of the way along your route you divide the correction angle by 1/4 or something like that. So far i've never needed it as so far i've never needed to use it. But should the day I need it come ... :uhoh:

Any help/techniques would be gratefully appreciated

PC

[LH2]

The whole point of the exercise, having realised that you are off track and determined by roughly how much, is to work out a rough course which will get you going in the right direction. In practice this could be either getting back to your original track, or a new track direct to your destination/next waypoint.

Now, how you do this is entirely up to you, as long as your method is reasonably quick and accurate (so that you do not make the situation worse, possibly bust airspace, etc.) What the instructor is teaching you is purely one suggested method, it is advisory not compulsory (although he might want you to demonstrate it, just humour him and move on).

Personally, when dead-reckoning I just have a look at the chart once in a while, then if I have to say "Bugger, I'm a mile off", I proceed to eyeball the new track and fly a roughly suitable heading. Sometimes there is a feature you can aim for to make life easier.

If flying under a radar service then another option is to simply ask for a vector. Then there is the GPS and other navaids, but that entails having to work buttons and dials and adds to your workload.

In summary, just use the simplest method which works for you.


Pre-emptive note to IO540: I know, I know... but some of us actually like doing a bit of dead reckoning for the fun of it. Ideally in a no-radio, open cockpit biplane, for better WW1 effect :E

[NorthSouth]

PC:

No offence to my fellow ppruners but the best way to get your head round use of the 1:60 rule is to read the text book - Jeremy Pratt, Trevor Thom, whichever is your preference.

The basic starting point is that if you're one mile off track after flying straight for 60 miles, you will be one DEGREE off track. When in the air you can use multiples/fractions of that to work out how many degrees off track you are. But 1 in 60 has many more uses than that.

NS

[Shunter]

In my opinion the best thing to do with the 1in60 rule is not bother with it. Skills tests will load your brain fairly heavily as it is, and trying to figure out the 1in60 rule in flight doesn't help.

On my CPL test I just used closing angle corrections to regain the original track, then correct the heading for unforecast wind etc... much easier to remember.

[Pull what]

The 1 in 60 rule is excellent over areas without visual navigational features, water, desert, unpopulated areas but for general navigation in this country most people make small corrections to map read themselves back onto track based on 5, 10 or 20 degree corrections left or right as appropriate. Practice with a map using both the rule and guestimation, you will find you will be always close to the calculation

[xrayalpha]

Try:

60 dots on the dog!

ie:


60 x Distance off track
___________________

distance gone


That then gets you parallel to original course.

Try doubling it to get back on track in the same number of miles that it took you to get off track.

But remember if getting near the Manchester low level corridor or the Kilmarnock corridor - for instance - you could then bust controlled airspace as you get back on track!

Waste of space in UK, one of those classics from the 1920s that everyone still teaches but is off little practical use.

[Gertrude the Wombat]

The basic starting point is that if you're one mile off track after flying straight for 60 miles, you will be one DEGREE off track.
Theoretically true but in practical flying terms completely useless, because nobody can fly to anything remotely near one degree accuracy. (Leaving aside autopilots and suchlike.)

In real life if you are one mile to the left of where you should be, you point right "a bit" until you're back on track. The best way to do this, as others have said, is to spot something out of the window that is on the correct track, and aim at it.

The really clever trick is to have a quick look at the map and ask yourself a question like "if I am a mile to the left of where I should be, have I already busted controlled airspace, and, if not, how quickly will I do so if I carry on like this?". From this you can have a guess as to how much "a bit" is.

There's really no point (if you've got a brain like mine) trying to remember bizarre and arbitrary "one in sixty" rules. Where the "one in sixty" rule comes from is the "facts" that


pi is three, near enough
sin(x) is x, near enough, for small x, and I'm only ever going to be off course by a small angle, aren't I, honest guvand given those facts (which I remember from O level maths anyway, certainly vastly more easily than I can remember some random numbers like "one in sixty") you can do the trig in your head if you really have some pressing reason to come up with a numeric answer for "a bit".

[LH2]

Err... I assumed the original poster knew what the 1:60 rule is, and was asking about how it's applied in PPL navigation. But re-reading, maybe I was wrong.

The 1 in 60 is a rule of thumb, i.e., a simplification of some formula or principle which can be applied with minimum calculation effort. As a simplification, it's meant to be just "good enough", which is why you use them for sorting out small nav errors for example, but not for calculating TODR on a commercial flight (although you would still have a rough guesstimate in your head, to catch any gross errors).

As regards the problem at hand, your goal is to identify your track error--e.g., say you were supposed to be flying a track of 210°, but 60nm from your last waypoint, you cross-check on the map, and that feature you were expecting to overfly is not directly below the plane but, you estimate, about 1nm to one side (say on your right hand side). Now you know that whichever track you were flying, it wasn't 210° but something else, and you would like to have an idea of what that something else might have been so that you can come up with a strategy to get back on track.

This is simple trigonometry, where you have a right triangle formed by sides (a), (b), and (c), and angles (A), (B), and (C), where for the sake of argument we call (a) the hypotenuse, formed by the distance flown from your last waypoint (where your track error was zero), (b) your distance off track perpendicular to your planned track, and (A) is the 90° angle, opposite (a). If you can bear my ASCII art:

..........(B)
..........*
..........|.\
..........|..\
.....(c).|...\..(a)
..........|....\
..........|___\
.....(A)..(b)...(C)

(The dots are to stop this piece of **** of a so-called bulletin board eating up the spaces :rolleyes:)


Now, we know that knowing at least one side and any two other elements, we can solve for the remaining elements of a triangle. In our case, we know the two sides (a) and (b) and the one angle (A) = 90°, and our goal is to find the angle (B). From Euclidean trigonometry we have that (B) = atan(b/a). In our example: (B) = atan(1/60) ~= 0.95484° which is roughly one arc degree.

So now hopefully you see where the 1:60 rule comes from: for small angles, one arc degree subtends approximately one unit of length every sixty units of length (of course it doesn't matter which units you choose, be they nautical miles, metres, fathoms, smoots, or your maternal uncle elbow's length). This rule of thumb holds true to within about a 5% error for angles less than 8°, and within a 10% error for angles less than 20°.

Now for practical applications on a navex you've got to options: you can either wait until you've flown for 60 nautical miles to ascertain your cross track error, or you can use cross-multiplication. So if for example you have flown for 30nm and you estimate your cross-track error to be 2nm, then (1/60)/1 = (2/30)/xte => xte = (2/30)/(1/60) = 60/15 = 4. Your track was about 4° in error, and knowing this you now can come up with a course correction strategy for either getting back on track or proceeding direct to your destination. The simplest strategy is that if you now fly a track which is 4° less (if you are right of track) or more (if you are left of track) than the original track, for a distance equal to your elapsed distance from the last waypoint, you will regain your original track (at which point you should make a new course correction of 4° in the opposite sense as before, or you will overshoot). Note that, because you were flying a track 4° in error, and when you make your correction essentially you will be flying another 4° in error in the opposite sense, you will make an 8° turn.

From simple logic, it follows that if you want to regain track faster you will apply a bigger correction. E.g., 8° correction [12° turn]) and you will regain track in half your elapsed distance, and so on and so forth. Another strategy is simply to work out a new track to your next waypoint (by drawing a new line on your map), or to spot an easily identifiable feature such as a village (do not misidentify) or a valley (idem) which lies on your original track and fly to it. In every case, make sure you are not going to get in trouble by doing whatever you've decided to do (airspace, terrain, weather, etc.). If in doubt, a 90° turn might be a sensible option.

Anyhow, hopefully that's the 1:60 rule explained. I haven't got time to re-read the above so apologies for any errors or omissions. HTH.

[Jofm5]

(The dots are to stop this piece of **** of a so-called bulletin board eating up the spaces :rolleyes:)



Apologies for thread drift - but the eating of spaces is due to a proprtional font being used.

If you want to display something without proportional spacing either switch to courier new which is not proportionally spaced.


Or use the code button on editing

Which is on the toolbar as the # symbol.

[Tinstaafl]

Previous threads about this topic:

http://www.pprune.org/flying-instructors-examiners/13346-1-60-rule-please-explain.html

http://www.pprune.org/private-flying/296489-help-1-60-rule.html

http://www.pprune.org/flying-instructors-examiners/14010-flight-navigation-techniques.html

[BEagle]

Ask your instructor to explain the 'Standard Closing Angle' technique. If he doesn't know, either ask him to find out or find a new instructor!

[Cows getting bigger]

Beagle's SCA is intriguing and, to be honest, more difficult to understand (application is relatively easy).

Alternatively, draw a couple of 10 deg fan lines - one from departure point, the other to arrival point. Once you ascertain your position, use the fan lines to figure how many degrees you are off track so far and how many degrees you are off track to go. Add the two numbers and this is the correction you need to apply to reach destination. Simple, expeditious and no need for a further correction (all the other methods require a second correction when you have regained your original planned track).

[toolowtoofast]

In the real world, I reckon SCA works best and fastest to get back on track, with minimum thought having to go into it, however to learn 1:60, first practice using double track error questions, then change the 'distance to go' to a shorter distance than the one travelled - the process is the same as DTE, but will get you back earlier.

Daily flying though, Dead reckoning is the reality for VFR flight - 'it's somewhere over there on the other side of that hill - that's where I'm going' :)

[LH2]

Daily flying though, Dead reckoning is the reality for VFR flight - 'it's somewhere over there on the other side of that hill - that's where I'm going'

That's not dead reckoning, that's called pilotage.

[IO540]

Incidentally, is the above stuff applicable to a UK PPL? I don't recall doing any of this.

In visual nav, the trick is to pick only those waypoints that are clearly unambiguous (e.g. two lakes next to each other, rather than a single lake in an area littered with lakes), fly the computed heading accurately, and monitor progress as one is going along using similarly unambiguous landmarks along the route, and add/subtract say 5 degrees to one's heading if one is drifting off a bit. If the leg length is not excessive, say under 20nm, one can't be far wrong if one actually flies the heading accurately.

I gather that in the JAA CPL, one does all kinds of tricks but I never did the JAA one myself.

[LH2]

is the above stuff applicable to a UK PPL?

Yep.
. .

[Gertrude the Wombat]

(The dots are to stop this piece of **** of a so-called bulletin board eating up the spaces :rolleyes:)
Apologies for thread drift - but the eating of spaces is due to a proprtional font being used.

If you want to display something without proportional spacing either switch to courier new which is not proportionally spaced.

Back in the real world, the real answer that this is a web page.

Web pages are written in HTML.

The spelling of white space is not significant in HTML - one space or a thousand spaces means the same, it's in the definition of the language.

If you want particular spacing, you can either use the non-breaking space entity or one of the tags that overrides normal HTML formatting.

[mountain-goat]

And in the most practical and simplest of methods in my opinion to use for a JAA ppl or cpl flight test is the: 'Knightson'... A circular transparent piece of plastic with 'wood rings' depicted with the major cardinals dividing the circle into four quarters (A big cross depicted over diminishing equally spaced circles). You plot the actual/forecast wind vector before flight with a "x"; so 090/10kts is 090 from the centre of the Knightson and two rings out from the centre on that radial (each ring representing 5 kts); place the "x" as the new centre of the circle (now skewed) where you are on the map, read off your heading already corrected for wind, add/sub MAG Variation and then you can count the equal distanced wood rings out from where you are to where you want to go to give an accurate ETA measured in minutes. Just make sure you align the depicted cardinals on the Knightson correctly with the map's True North when placing the 'x' over your current position on the map before reading headings etc. No fan lines needed - just wind corrected headings and ETAs measured and a lot less head down time! The size of the Knightson (and subsequently the scale of the circles) is dependent on the average cruise TAS of your aircraft. The Knighston is fixed for its respective TAS. Have used ones respectively for PA28 ppl and PA34 (Seneca) cpl skills tests.

Putting things on plastic doesn't always have to lead to debt :)

Good luck.

MG:ok:

[LH2]

Back in the real world, the real answer that this is a web page.

Yes, thanks. I know a thing or two about web pages and related stuff, but it was late, I'd just spent five hours on my bicycle, I was tired and my arse hurt a lot (from sitting on the bike). I couldn't find the pre-formatted text option (which someone since has kindly pointed out) and somehow I expected the BB would replace spaces with NBSP (which of course it doesn't).

My opinion of the BB software generally still stands.

And who said thread drift?

[toolowtoofast]

That's not dead reckoning, that's called pilotage.

Oops. Learning all the time!

From wiki: Pilotage is frequently combined with navigation (http://en.wikipedia.org/wiki/Navigation) techniques such as dead reckoning (http://en.wikipedia.org/wiki/Dead_reckoning). When a pilot at a known location cannot see the next visual reference on the route to a destination, he or she can use dead reckoning to get closer to the next reference point. This is the most common form of VFR (http://en.wikipedia.org/wiki/Visual_flight_rules) navigation

I guess that's where my confusion came from, but I had honestly never heard of pilotage - I always just thought - 'if I head south for 20 mins I'll be able to see the mountain, then I'll head for that....' was DR in its entirety

[mikehallam]

I radian is 57.3 degrees i.e. nearly 60.
[A radian is an arc of radius R to the length R round a circle's circumference.
Near enough to a chord.

Or think of an equilateral triangle, i.e. equal sides and equal (60) degrees each inside corner.

It's simplified calc. as one of many ad hoc tools for sensibly assessing & correcting a course when map reading.

Mike Hallam.

[Gertrude the Wombat]

"Pure DR" is where you don't look out of the window at all (or, there's nothing to look at, eg over an ocean) until you get to your destination. If you look out of the window from time to time and correct your course depending on what you see that's cheating, the pilot is applying brain power to overcome the limitations of DR!

[homeguard]

Whilst it may be fashionable to denounce anything that requires thought and structure as a futile waste of effort; the infringements of controlled airspace, danger areas and Red Arrows displays continue and from reports are getting worse. Sadly and most important pilots also become lost and spatially disorientated flying into all sorts of things, the results of which can become tragic.

Whether some of you like it or not structured navigation training is crucial for the basis of by whatever means you navigate. There are of course many ways to skin a cat and just as many navigation techniques. That doesn’t matter; the important thing is that a methodical structure is taught. GPS is based logically using Radians, i.e. 1:60 and Descartes grid, so the pilot should have a basic understanding of the use of the rule just the same when using a GPS and should it fail.

Use of the 1:60 as a working base to navigation is perhaps the simplest available. The number 60, as said, is a rounded up Radian. The actual definition of a Radian is; that its angle subtends the length of arc. To see this; draw a circle and from the centre of the circle draw two lines 60 degrees apart. Between the two points that each line crosses the circumference take a measurement. Compare this measurement to the length of each line (radius). You will discover that the length of the arc is almost the same as the length of each of the two lines. I say almost because the circumference is of course an arc, a curving line. Reduce to angles of less than 20 degrees and discover that the difference between the arc and the straight line is impossible to measure on a standard chart. Incidentally 20 degrees is one third that of 60 so therefore the distance off track would be one third off the distance gone.

Treat one radius line as the intended track and the other as the track made good. At a point 24 miles along the intended track take a measurement between the two tracks and divide the distance gone by the distance apart which we will say equals 2 miles.. E.g. 24 miles flown is divided by 2 miles off track which equals a ratio of 12. Divide the radian 60 by the ratio 12 = 5. You are 5 degrees off track. The1:60 formulae commonly given in the text books is to divide distance off by distance gone and multiply by 60 (2\24x60 = 4.999). You may also divide the degrees off track into 60 to find the distance in miles that you are off track. 60\5 = 12 therefore 24\12 = 2 miles off track.

The simplest way is to pre-determine the points along the track where you will assess your progress known as a ‘pinpoint’ or ‘mid track fix’ which doesn’t have to be half way or quarter way, and draw 5 or 10 degree fan lines abeam the point – no need for any sums other than to double or treble the track error as appropriate to regain track. You will regain track should you double the error in exactly the same time and distance or by trebling the error in half the distance and time. You will now have a point and an ETA to regain track.

The 1:60 allows for velocity as well simple angles. Your aircraft is flying at 100kts with a wind 90 degrees across at 20kts. 100\20=5 therefore 60\5 = 12, your drift is 12 degrees. All sorts of navigation problems can be understood by understanding Radians, the 1:60 rule.

[ExSp33db1rd]

Buy a handheld GPS.

or .... draw lines at 10 deg either side of track starting from the start and back from the destination. Fan lines someone has called them earlier.

When you have fixed your position as being halfway between your desired track and the 10 deg line you have drawn from the start point, that is 5 deg off track, but the same point might only be 1/3 of the way between your track line and the 10 deg line from the destination, call that 3 deg.

If you only turn 5 deg toward track you will only parallel, but if you add the 5 and the 3 and turn 8 deg. towards track - Bingo ! Works for any distance along track, not much maths involved.

If I knew how to post diagrams to PPRuNe I'd show you.

The real trick is not to try to do a maths exam in a rattling steel cabinet, big numbers, commonsense

( Oh! and buy that GPS ! )

Used to navigate 707's with a sextant, recently flew a microlight into controlled airspace, needed a second bearing to make my report to ATC, couldn't be bothered re-programming the panel mounted GPS, pulled a handheld from my pocket - had to laugh, sextants in 707's, now 2 GPS's in a microlight !!

Use the KISS method. Keep It Simple, Stupid.

[KandiFloss]

Hi all,

Thanks for everyone's tips and advice! I've just put my brain back together after it just exploded after trying to get my head round some of techniques.

Thank you ExSp33db1rd (and anyone else who gave a simple version) for a nice simple version! Will go away and try working with that as some of the other techniques are just too cranial for me :uhoh:

[ExSp33db1rd]

Pilot Chick

When learning to navigate BIG aeroplanes, an old navigator ( tho' younger then than I am now ! ) once told me to pretend to be sat on the tail of the aeroplane and to just steer it across the map.

Of course you have to consider wind-drift and magnetic variation, but don't get bogged down with science.

One had a trainee co-pilot try to steer me 310 deg. from Singapore to Australia ( think about it ! ) he had done the maths and got it wrong, and totally forgot The Big Picture.

Pass your exams - then buy a GPS ! Shouldn't say that, but GPS's are OK if you first know the basics of navigation, if one removes some of the mental gymastics, and allows you more time to keep your eyes out of the cockpit - why not.

Some people enjoy the challenge of really accurate navigation, and it is fun to see how science works, but don't lose sight of what you are trying to do, have fun, get where you are going, and don't fly into mountains, other aircraft, or prohibited airspace !

Good luck

[Bigglesthefrog]

Hmmmm.... I will bet you a pound to a pinch of Pig muck that all those that have put forward an explanation for the 1 in 60 rule completely forget about it when they are navigating their aeroplanes across good old blighty. Unless you have a dedicated navigator sitting beside you that you can trust to do all the sums associated with this, I would do what I suspect 99% of pilots on here that use a chart do, and that is follow the china graph line that you drew on the half million when you planned the flight. We don’t live in the desert; we live in a land with lots of recognisable towns, motorways, railways and many other landmarks. Granted, we also have the occasional bit of bad visibility too, but if you can’t see the ground properly you should still be sitting on it!
In my view, you draw the track line on the map and then you draw on the wind vector. You do your calculation on what heading to fly and check this out regularly from the moment you take off with landmarks as you go along the track. If you are a bit to the right of the line, then steer a bit more to the left and check things again in a few minutes making more alterations if it is necessary.
Navigating like this with “Mk1 Eyeball” ensures that you get an accurate appreciation of where you are AND affords the important requirement of LOOKING OUT OF THE WINDOW!
I bet another pinch of Pig muck that the same guys I referred to at the beginning of my statement have a nice little GPS perched somewhere on the panel and Why not indeed? Because a GPS backed up with a current aviation chart provide a great navigation setup that is accurate, easy to use and takes most of the worry out of the operation allowing one to enjoy the flying.
1 in 60 rule…… straight into the waste paper basket would be my advice:ok:

[vee-tail-1]

My pennyworth. How often is the standard liquid filled compass commonly fitted to GA aircraft telling the truth? It is usually overeading, underreading, oscillating, or going round in circles. If it does stay still long enough to make an in flight correction to the DI you then have the problem that most DIs have an unknown rate of precession.
GPS and chart works for me.

[stickandrudderman]

I'm with Bigglesthefrog!

[GearDownFlaps]

apart from the atpls, RA60D , never understood it never used it and thus far never suffered as a result of this

[ExSp33db1rd]

....... and go IFR. ( I Follow Roads - or railway lines )

( Not sure that Pilot Chick really wants to know, but maybe needs to know for her exams? )

[KandiFloss]

ExSpeedBird: IFR - I follow Roads ... I like that! :ok:

It's a bit embarrasing to admit this but I do actually have a PPL, it's just that i've never got my head around the 1:60 rule. I just think that I should try to understand it now that i've clocked up the grand total of 79 hours Dual and 20 hours PIC - hey:D! I guess that must be a decimal fraction of your flying time?!

GearDownFlaps: I'm glad that you said "never understood it never used it and thus far never suffered as a result of this" it helps me to admit this too :uhoh:. As they say in 'help' groups ... "Thanks for sharing" :ugh:

[Tinstaafl]

I've flown thousands of hours using 1:60. Not just across desert, farmland, bush, towns or wherever but also for tasks such as finding the height of a weather radar return, finding a lead bearing for starting a turn to intercept a radial/localiser beam, determining maximum drift for a known or estimated crosswind component etc.

Pretty much anytime you need to convert an angle to or from a cartesian coordinate that involves our hexigesimal time or angle systems.

Off track corrections can be done in your head to an acceptable level of accuracy. You only need remember '1, 2, 3, 4 & 1 and a half' and when to use those numbers. It's a three step problem: First to stop diverging from track any more, second to fly towards track, and third to maintain track again.

Step 1: Find the angle of the divergence from track (Track Error or TE) to use to adjust heading to stop any more drift.
Step 2: Find the angle needed adjust heading to close towards track, regaining track at some chosen point (Closing Angle)

Adjust heading by both those amounts ie Track Error and Closing Angle, and then:

Step 3: Remove the closing angle so you maintain the track you just regained.

Step 1: Track Error

If you find yourself off track and have flown any distance that is something like 60nm (say 55nm to 75nm or so) then multiply the distance off track by '1'. For example, flown 55 miles since last on track and fix your position 3 miles off track then multiply the distance off by '1' to find the angle by which you diverged away from the desired track. In this case 3 degrees. If you alter heading by 3 degrees towards track you will parallel track.

If you have flown somewhere around 30 nm use '2' eg flown 34 nm and find yourself 4 nm off track: 2 x 4 equates to 8 deg drift. Alter heading 8 deg towards track to parallel track.

Flown around 20 nm? Use '3 times' eg Flown 19 nm and are 2 nm off track? 3 x 2 equates to 6 deg Track Error. Alter heading 6 deg towards track to parallel.

Flown around 15 nm? Use '4 times'. 16 nm flown since last on track and 1 nm off track? 1 x 4 = 4 deg off track.

If the distance flown is about 45 nm then use 1 1/2 ie 1 x the distance off track + another half of that eg flown 42 nm and 4 nm off track: 1 x 4 = 4 degrees + an extra 'half' of that figure. 2 in this case so Track Error = 6 deg.

Step 2: Closing Angle

Choose a point where you would like to be back on track again. It could be the destination, next turning point or even just some feature that is easy to find.

Use the same method as for Step 1, but use the distance from your present position to the chosen point on track. For example, the point where you would like to regain track is 35nm away and you're 4nm off track. 2 x 4 gives 8 deg needed to alter heading to close track.

Adjust heading towards track by the amounts you just worked out in Steps 1 & 2.

Step 3: Maintain Track

Later, when back on track, adjust heading to remove the Closing Angle found in Step 2 eg Track Error was 6 deg, Closing Angle 8 deg gave total heading adjustment to get back on track of 14 deg. Now that you're back on track turn towards your original heading my 8 deg. That leaves you with your original heading corrected by the Track Error only.

Using the method requires only a few measurements : Distance Run since last on track, Distance to go to get to the back on track position, and distance off track, and only takes moments to do. It's usually possible to see ahead of time where you will fix your position off track so those measurements and even the calcuation can be done ahead of time so when you fly over the off-track fix all you need do is turn towards track by the calculated amount and log the time.

Further, the Distance Run & Distance to Go you measure can then be used to find your groundspeed and revised estimate for the destination/on track fix, killing two tasks with one set of distance measurements.

[ExSp33db1rd]

and don't forget to watch your height, apply a bit of carb/ heat, re-set the D.I., avoid cloud, keep away from that restricted area, change radio frequency, give your pax. a sick bag, tell the youngest in the back seat to shut up whilst you listen to the ATIS etc. etc.

Buy a GPS - 2 if you are worried about one failing at the most inopportune moment - as it will one day.

[Tinstaafl]

If that sort of workload balancing is too much then I'd have to think either incompetence, or the need for a licence limited to either mandatory
GPS equipment or flight with a co-pilot, flight engineer, navigator, radio operator & a flight attendant

It's just not that hard to measure 3 distances on a 1:1,000,000 or 1:500,000 or 1:250,000 scale chart and note the time & next HDG at a pinpoint or fix. Christ, I even manage to do it with my calibrated thumb & a pencil without drama. Everything else can be done looking out the window.

[ExSp33db1rd]

Preferably all of the above !

Flying my single seat microlight around NZ, it's a real hardship not getting that first cup of coffee 30 secs after lift off. ( or the Brake Dwell Cocktail after landing - but that's a secret - and my lips are sealed ! )

Read my post #26. It's Horses for Courses, put me in front of an FMS or a Glass Cockpit and I wouldn't have a clue ( at least, not much ) I don't even answer a Text message on my cellphone - too hard, but if the methods you are happy with, work for you, no problem, but if I were Pilot Chick I'd have run off screaming under the nearest passing bus by now !

I was told that I'd never make a navigator as long as I had a Hole in my A**** until I'd been over Berlin with the shells coming through the cockpit whilst I was trying to get a 3-wind drift fix with the Drift Sight. I never had to.

I watched my own Nav. students in despair sometimes, trying to cope with Sight Reduction tables and the St. Hilaire method of working out an Astro fix with a sextant - then came along INS and now GPS, and they've never had to.

Of course one must understand the basics before playing with the toys, but after that, whatever works for you, and I repeat - KISS ( Keep It Simple, Stupid )

Recently flying the microlight, I needed a cross bearing, rather than re-programme the panel mounted GPS, I pulled a handheld GPS from my pocket, I guess I could have used ' the-length-of-the-ball-point-pen-cap-equals-20 miles-and-I-can-guess-around-150-deg-relative-bearing ' method, but it was just easier.

QED

[BluntM8]

PilotChick,

If it helps, I have to think of the one in sixty in terms of dumper-trucks (don't ask why...). I know that if I go sixty dumper trucks along, and one to the side, I've made a degree. From that I can work backwards for lesser distances. 15 dumper trucks along and already one sideways? Must be 4 degrees!

I'm now a navigator on Tornado GR4....

Draw your own conclusion!

Blunty

[Dashtrash]

Pilotchick,

I'll see if i can explain this without trying to draw it. hmmmmm

1:60 was beyond me for most of my flying training. I only learned this method when I started working as an instructor for a lovely old guy who I think had entries of W.Wright in his logbook....I digress.

Take each leg of your plan on the chart. Draw 10degree splay lines on either side from start and finnish points of the leg (point A-B). What you'll end up with is a line if diamond shapes along your route. (diamonds are a chicks best friend). Apply common sense here and don't try it on short 10nm legs.

What these diamonds provide you with is a scale to make accurate guesses.

Now, picture yourself inlfight. You fix your position a little off track. With the 10degree lines you can quite accurately estimate your track error (from A) and correction angle (to B). Add the two together and alter your heading by that much.

It takes a little bit of extra time in the pre flight stage but you will be more confident about flying longer, more direct and accurate VFR legs.

The only catch is that you MUST maintain your heading. You can't apply a correction to a heading (with any method) if you've havn't maintained one to begin with.

Hope that helps. Feel free to PM if you need any help deciphering all of this.
Happy flying

[mikehallam]

Problem with lots of lines drawn on the chart extra to the route (and a few circles round danger spots) is that it clutters it up. The classic chinagraph lines are fat & obscure bits too.

If one is off course, and over ground features where reading them to chart is feasible, just change course a bit to corrrect. It really doesn't matter what angle, but gently is more efficient.

If you're, say, flying 5 degrees off track & persist with this, all other things being equal, you will be 5 miles off to one side in 60 miles. And pro rata.

So unless you're following a badly mistaken course plot, you're never going to be too far off if correlating features regularly crop up.

Now if it's another thing altogether when featureless terrain/water is crossed !

[Crash one]

The 1 in 60 rule is excellent over areas without visual navigational features, water, desert, unpopulated areas

Now if it's another thing altogether when featureless terrain/water is crossed !

Could you please explain how the 1-60 rule is of any use over water/featureless terrain?

[Tinstaafl]

You need at least 3 identifiable features. One at the start of the track deviation, one for the off track fix and the third at the track regain fix although you could DR the last one with some loss of certainty of position.

[Munnyspinner]

At halfway your correction angle CA will be 2 X Track error (TE)

at 1/4 CA= 1.5 X TE
at 3/4 CA= 3 X TE

Basically, the rule is that for each 1 degree deviation from planned track the aircraft will be 1 nm off track after flying 60 miles.

So,
(distance off track ( in nm) /distance travelled(nm)) x 60 = TE in degrees.

and,

( distance off track ( nm) /distance to go(nm)) x 60= Closing angle in degrees

Correction angle = TE + Closing Angle.

At the halfway mark Distance travelled and distance to go is the same so TE and closing angle have equal values hence Correction angle = 2 xTE


If you like maths there is a much more detailed explanation - but you can work that out. Think about Sine rule.

[Munnyspinner]

Featureless terrain or water - now there's a challenge. Is this from point of origin to point of arrival or only over part of the route.

You will still be flying along your chinagraph pencil line but have no ground features to refer to. You will still be able to establish the expected position on the line form elapsed time. So you will then need to get a fix using VOR/ADF which will give you an approximate position which you can assess relative to you original track.

If you're making long flights over water or desert the a GPS would be advisable.

[mikehallam]

Exactly, then it's DR for the featurelss portion !

[Fark'n'ell]

If you're making long flights over water or desert the a GPS would be advisable.

Or a sextant.:ok:

[hhobbit]

try these "real numbers" :
I am on (already computed) heading 285
XTE
I am now aware of being 3nm to the right after 27 miles
I am doing 89 kts
FIRST CORRECTION
so I turn 50 deg to the left immediately ( I've memorised this number)
my aim is to get back on track in 3nm/min that's 3 min.
SECOND CORRECTION
now time to think is about 2.5 min...
recall 3 to Right having run 27 approximates 6 in 60 or 6 deg
I now turn an extra 6 deg to the left.(optional)
THIRD CORRECTION
3 mins up: original 285 less 6 say 280 should do it for amended heading. If that optional extra correction was made as above, the corrected heading will be 50 deg to the right, a reversal of the original sharp turn. Otherwise its 50-6=44 to turn to the new heading.

80kts turn 50(49)
90kts turn 45(42)
100kts turn 40(37)
110kts turn 35(33)
120kts turn 30(30)
figures in brackets are precise.
track error is always positive and never greater than 7%

now put in your own numbers

I think its quick and dirty!

[Chimbu chuckles]

Ok crash one, and anyone else that is interested, an example of use of the 1/60 over ocean/featureless terrain.

Once upon a time, some years before GPS came on the market, I was tasked with flying from A to B, at night, over the Solomon Sea from PNG to Honiara in a Beech Queenair. I had to track via an NDB on a small Island called Gizo (due IFR enroute navaid requirements) and then down The Slot to Honiara.

As an aside it was a PNG Govt charter and they required 2 pilots so a newbie, who arrived in PNG that morning, was tasked to warm the right seat. The pax were duly loaded, along with some locked large tin boxes (which I was not allowed to know the contents of) and away we went.

Our point of departure had a VOR/DME but terrain would ensure that we lost reception of those not far past TOPC. My plan was to fix my position before we lost those navaids and then do a 'Running Fix' (something I learned navigating yachts on coastal races as a teen (LONG before even Satnav let alone GPS) as I passed abeam an Island with an NDB that would be barely in range - but better than nothing. A Running Fix is when you take a note of the time your relative bearing to a place is 45 degree off and 90 off - if you know your speed then it is easy to calculate how far abeam you were at the 90 off and, therefore, whether you're on track/how far off track and do a 1/60 to resolve any issue. All based on an Equilateral Triangle.

Just past TOPC I gave the DME dist from departure and the time to my 'copilot' and we preceded on our merry way as the sun set rapidly behind us. Some hours later I tried to record the 45/90 off but never received the aid - it only surprised me slightly - this being the SWP navaids were always failing and going unreported for days. I asked my erstwhile companion for the dist/time I had given him before - "Dunno, I didn't write them down".

:hmm:

As I sat there pondering this something that I couldn't put my finger on but that had been bugging me since before we departed suddenly made itself manifest. I handed over control to the newbie (no autopilot - well except for the voice activated one in the RHS) and pulled out the weather reports and perused the forecast winds aloft which I had dutifully applied to the track we were flying giving us a heading. Memory dims but they indicated NW at about 15kts (our track being ENE). It suddenly occurred to me that this was the wrong time of year for NW winds - it was the SE Trade wind season and they typically blow at 15-20kts. In my defense I was a bush pilot who spent his days in the mountains flying VERY short legs between mountain strips and NEVER applied wind to a flight plan in the normal course of a working week...or month...in fact not for a few years.

I turned to my copilot and informed him I believed we were left of track - a long way...which was why we never got the Misima NDB. He sorta looked wide eyed as I explained my logic. Fair enough it was his first day using his brand new CPL.

I sat there with my chart and a pencil and calculated where I believed we were based on the heading I'd been holding (very carefully) and what I believed the real upper winds were. I then worked a DR 1/60 to track direct to Gizo figuring we'd only have to be within +/- 30nm to actually pick up the NDB and make a final course correction.

From memory the heading change I came up with was 40 degrees.:uhoh:

I don't remember what my copilot actually said - but the look on his face was a mixture of horror and 'you gotta be ****ting me'. He'd only met me for the first time 6-7 hours before.

I retook control, altered heading (with my heart in my mouth) and we droned on into the night - me with a very real sense of how Earhart had felt in this same area 50 years before.

Maybe another hour passed and I was really expecting to be well within the range of the Gizo NDB soon if not already - only a DR GS to work off but how far out could I have been? The ADF just swung lazily around the dial - plenty of Equatorial Night TSs around and it was doing its poor mans weather radar imitation.

About 20nm ahead was a line of TS - I intently watched a spot that stayed dark just a fraction right of the nose - maybe a nm or two off my new track - and aimed us through it - no weather radar. 5 minutes or so later we bashed our way through the line of storms and...there was an Island!!

Quite possibly the most beautiful island I have ever seen, bathed in moonlight and ringed by villages...maybe 20nm away. And right then the ADF sprang to a relative bearing of damn near 0 degrees and held steady, the ident booming through within a few more minutes. Some time later I learned that the Gizo NDB had an effective range of about 20nm...on a good day:suspect:

We turned overhead the NDB 5 minutes ahead of my DR estimate and flew down the Slot under the glow of a fantastic moon and landed at Honiara. My new best mate now thought I walked on water.

Last I heard he now flies Airbus for Cathay and I fly Boeings for another airline.

Maybe an irrelevance today with handheld GPS virtually in every pilots navbag - but technology can fail and all you have left is your brain and the basics - to prove the point some years ago both my FMCs failed departing LHR - I reverted to VOR/DME/ADF and continued on to Dubai - we made up time and landed under burn - and most of all I had a BALL doing it. It turned a normally boring sector into a very interesting one.

Oh and the big tin boxes I couldn't look in?

Weapons - I had unknowingly taken a paramilitary hit team to the Solomons to sneak over onto Bouganville Island and attempt to kill the leader of the Bouganville Revolutionary Army. A week later I did a second trip over to drop off a ships captain and when I checked into the Mendana Hotel there on my bed was that days Honiara Star newspaper and it was all over the front page. They had been arrested in the Western Solomons.

We (same young fella in the RHS - hell I was only in my late 20s) checked out the next morning and departed back to PNG all the time expecting to be arrested - but were not even asked a single question.

Had we not altered course there is no land we would have spotted we would have droned out into the Pacific with no accurate idea where we were.:sad:

Ahhh the good old days:ugh::}:ok:

[Crash one]

Chimbu chuckles
Now that is navigation. Brilliant stuff.
Unfortunately my bug smasher has no VOR, ADF, DME, transponder etc. I have a compass & a PDA Memory Map GPS device which I hope will be enough. I am too old & too late in the game to aspire to such feats, but I admire those who have & do.

[BluntM8]

You need at least 3 identifiable features. One at the start of the track deviation, one for the off track fix and the third at the track regain fix although you could DR the last one with some loss of certainty of position.

Agree, but as an aside, have you ever tried flying with a blank sheet, with just the geometery drawn on it? As a way of proving that what is underneath doesn't matter it's amazing!

The simple maths, when applied carefully, is brilliant!

[Tinstaafl]

Done the equivalent to a blank sheet of paper by flying over the top of a hundred miles of fog/low cloud. In my instructing days I loved finding a nice fog morning for my CPL students who couldn't trust headings & DR. New South Wales west of the dividing range in winter was a great time for that but I've also had charters to no-navaid airstrips in Queensland that had the same issue.

Flying across the deserts in outback Australia requires a good grasp of navigation & track correction/ground speed/ETIs. The lack of ground features meant planning track corrections to arrive on track at some miniscule feature that could be seen. Some of my most enjoyable navigational tasks were flying direct from NW. Western Oz to Alice Springs in Central Australia & then direct to Birdsville or Eastern Oz.

Fog & low cloud was a common problem flying in the Shetland Islands. TAS as heading rarely worked due to the gale force winds. Doesn't change the basics of navigation though.

Flying around the Bahamas dodging TS at low level is also an area where good DR & 1:60 skills are beneficial. Not always a convenient navaid in reach.

[ExSp33db1rd]

Long story, might have mentioned it, but I knew the Capt. who crossed the Arctic regions ANC to LHR part way, using two toothpicks stuck into 2 pieces of cheese chunks. Steered a constant Sun line - shadow of one toothpick over the other. He wasn't so much unsure of his positon as being without a reliable heading reference - i.e. a Compass. Sun moves around at 15 deg / hour. Used that to do the rest of the maths.

[Tinstaafl]

That sounds fascinating. Tell us more about it.

[ExSp33db1rd]

" ..That sounds fascinating. Tell us more about it..."

?? PM ??